Patent Publication Number: US-2006002110-A1

Title: Methods and systems for providing lighting systems

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
      The present application claims the benefit, under 35 U.S.C. §119(e), of the following U.S. Provisional Applications:  
      Ser. No. 60/553,111, filed Mar. 15, 2004, entitled “Lighting Methods and Systems;” 
      Ser. No. 60/553,318, filed Mar. 15, 2004, entitled “Power Control Methods and Apparatus;” 
      Ser. No. 60/558,400, filed Mar. 31, 2004, entitled “Methods and Systems for Providing Lighting Components;” 
      Ser. No. 60/558,449, filed Mar. 31, 2004, entitled “Systems and Methods of Assembling and Connecting Solid State Lighting Modules;” 
      Ser. No. 60/586,939, filed Jul. 8, 2004, entitled “Integrated White Systems;” 
      Ser. No. 60/588,090, filed Jul. 15, 2004, entitled “LED Package Methods and Systems;” and  
      Ser. No. 60/608,847, filed Sep. 10, 2004, entitled “Lighting Zone Controller Methods and Systems.” 
      Each of the foregoing applications hereby is incorporated herein by reference. 
    
    
     BACKGROUND  
      LED lighting systems are known that provide illumination and direct view effects. A need exists for improved components for such lighting systems and for improved methods and systems for powering, making, addressing, cooling, and controlling such lighting systems. A need also exists for improved systems that take advantage of LED lighting systems.  
     SUMMARY  
      The methods disclosed herein include a method of determining an identifier of a networked lighting device among a group of networked lighting devices, the method including providing a plurality of lighting devices with multiple bit binary identifiers, the plurality of lighting devices arranged in a network, delivering a plurality of signals to the lighting devices, observing a condition of the network in response to each one of the plurality of signals, and inferring an identifier of at least one of the plurality of lighting devices based on the condition of the network.  
      The method may include mapping the identifier to the at least one of the plurality of lighting devices. The condition may include an indication of power drawn by the plurality of lighting devices in the network. The condition may include an exceptional condition of the network. The exceptional condition may include a short in a data communication path to at least one of the plurality of lighting devices. The exceptional condition may include a short in a data communication path to a lighting unit associated with at least one of the plurality of lighting devices. The condition may include a lighting condition of at least one of the plurality of lighting devices in the network. The condition may include a time required for a networked lighting device to respond to a signal on the network.  
      In the method, the plurality of signals may be delivered according to a binary tree search algorithm. The plurality of lighting devices may include at least one string of lighting units. A determination algorithm may be used to determine a location of the at least one string of lighting units. A determination algorithm may be used to determine a number of nodes on the at least one string of lighting units. A determination algorithm may vary power to the at least one string of lighting units and monitor responsive behavior of the at least one string of lighting units. A determination algorithm may include a binary search tree algorithm.  
      In another aspect, a system disclosed herein may include a plurality of lighting devices with multiple bit binary identifiers, the plurality of lighting devices arranged in a network; and a controller adapted to determine an identifier for at least one of the plurality of lighting devices by delivering a plurality of signals to the plurality of lighting devices, observing a condition of the network in response to each one of the plurality of signals, and inferring the identifier of the at least one of the plurality of lighting devices based on the condition of the network.  
      In the system, the identifier may be mapped to the at least one of the plurality of lighting devices. The condition may include an indication of power drawn by the plurality of lighting devices in the network. The condition may include an exceptional condition of the network. The exceptional condition may include a short in a data communication path to at least one of the plurality of lighting devices. The exceptional condition may include a short in a data communication path to a lighting unit associated with at least one of the plurality of lighting devices. The condition may include a lighting condition of at least one of the plurality of lighting devices in the network. The condition may include a time required for a networked lighting device to respond to a signal on the network.  
      In the system, the plurality of signals may be delivered according to a binary tree search algorithm. The plurality of lighting devices may include at least one string of lighting units. A determination algorithm may be used to determine a location of the at least one string of lighting units. A determination algorithm may be used to determine a number of nodes on the at least one string of lighting units. A determination algorithm may vary power to the at least one string of lighting units and monitor responsive behavior of the at least one string of lighting units. A determination algorithm may include a binary search tree algorithm.  
      In another aspect, a method disclosed herein includes providing a housing, the housing being substantially linear and including a first end, a second end, and a slot for receiving an array of a plurality of LED light sources; disposing the array of LED light sources on a circuit board within the slot; running an interior power/data feed from the first end to the second end; disposing at least one connector within at least one of the first end and the second end, the at least one connector adapted to connect the lighting unit to a similar lighting unit while allowing the two lighting units to be placed end to end without spacing therebetween; and providing a thermal facility for removing heat from a proximity of one or more of the plurality of LED light sources.  
      In the method, the lens may include an optical facility for operating on the light from the plurality of LED light sources. The optical facility may include a phosphor for shifting a wavelength of light emitted from one or more of the plurality of LEDs. The thermal facility may include an interior cavity of the lighting unit for moving air within the housing. The thermal facility may include a vent for releasing air from an interior of the housing to an exterior of the housing, at least one fin for radiating heat from the housing, a heat-conducting mass integral to the housing, a potting facility for receiving heat from the circuit board, a metal plate, or other thermal facility. The plurality of LEDs may include high-brightness LEDs.  
      In the method, a lens may be provided in a slot above the plurality of LED light sources wherein a profile of the lens may be co-planar with a top of the housing. The lens may be sealed to prevent a user from accessing the plurality of LEDs. The lens may be sealed to prevent a user from accessing a drive circuit on the circuit board. A power facility may be provided for the plurality of LED light sources. The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. The lighting unit may be a networked lighting unit. The lighting unit may be addressed using a serial addressing protocol. The lighting unit may be an addressable lighting unit. The lighting unit may be addressed using a determination algorithm.  
      In another aspect, a system disclosed herein includes a housing, the housing being substantially linear and including a slot for receiving an array of a plurality of LED light sources, the array disposed on a circuit board within the housing; an interior power/data feed from a first end of the housing to a second end of the housing; at least one connector within at least one of the first end and the second end adapted to connect the lighting unit to a similar lighting unit while allowing the two lighting units to be placed end to end without spacing therebetween; and a thermal facility for removing heat from a proximity of the plurality of LED light sources.  
      In the system, the lens may include an optical facility for operating on the light from the plurality of LED light sources. The optical facility may include a phosphor for shifting a wavelength of light emitted from one or more of the plurality of LEDs. The thermal facility may include an interior cavity of the lighting unit for moving air within the housing. The thermal facility may include a vent for releasing air from an interior of the housing to an exterior of the housing, at least one fin for radiating heat from the housing, a heat-conducting mass integral to the housing, a potting facility for receiving heat from the circuit board, a metal plate, or other thermal facility. The plurality of LEDs may include high-brightness LEDs.  
      In the system, a lens may be provided in a slot above the plurality of LED light sources wherein a profile of the lens may be co-planar with a top of the housing. The lens may be sealed to prevent a user from accessing the plurality of LEDs. The lens may be sealed to prevent a user from accessing a drive circuit on the circuit board. A power facility may be provided for the plurality of LED light sources. The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. The lighting unit may be a networked lighting unit. The lighting unit may be addressed using a serial addressing protocol. The lighting unit may be an addressable lighting unit. The lighting unit may be addressed using a determination algorithm.  
      In another aspect, a method or system disclosed herein includes providing an LED-based lighting unit, providing a housing configured in the shape of an MR-type halogen lamp; providing an MR-type connector for connecting the housing to a power source; disposing a plurality of LEDs in the housing; and providing a thermal facility for removing heat from a proximity of one or more of the plurality of LEDs, and/or systems for performing related steps.  
      In the system or method, the housing may be constructed from two cast halves or may be a single cast unit. The thermal facility may include a heat-conducting mass that is integral to the housing. The thermal facility may include a vent for allowing air to circulate from the housing, an internal power and data connection for the plurality of LEDs, a heat shield that protects one or more of the plurality of LEDs from heat generated by power/data circuitry within the housing, a potting facility for trapping heat away from one or more of the plurality of LEDs, a metal core board for accepting heat from one or more of the plurality of LEDs, or other thermal facility. The metal core board may be a printed circuit board. The plurality of LEDs may include at least one heat resistant LED.  
      In the system or method, a lens associated with the system or method may include an optical facility in a position to operate on light emitted from one or more of the plurality of LEDs. The lens may include a screw-type cap wherein a gap may separate the lens from the one or more of the plurality of LEDs. The lens may include a coating to prevent reflection of radiation back to the plurality of LEDs. The coating may reduce heat within the housing. The lens may protect one or more of the plurality of LEDs. The lens may prevent a user from touching one or more of the plurality of LEDs. The lens may prevent a user from touching one or more electronic components within the housing.  
      In another aspect, a method disclosed herein includes providing a housing, the housing being substantially linear and including a slot for receiving an array of a plurality of LED light sources, wherein the plurality of LED light sources are capable of producing substantially white light; disposing the array on a circuit board within the housing; running an interior power/data feed from a first end of the housing to a second end of the housing; disposing at least one connector within at least of the first end and the second end, the at least one connector adapted to connect the lighting unit to a similar lighting unit while allowing the two lighting units to be placed end to end without spacing therebetween; and providing a thermal facility for removing heat from a proximity of the plurality of LED light sources.  
      In the method, the plurality of LED light sources may include one or more red LEDs, one or more green LEDs, one or more blue LEDs, and one or more white LEDs. The plurality of LED light sources may include at least two white LEDs that emit different color temperatures of white light. The plurality of LED light sources may include one or more blue LEDs that include a phosphor. The plurality of LED light sources may include at least one white LED and at least one amber LED. The plurality of LED light sources may include one or more ultraviolet LEDs and one or more phosphors. The lens may include an optical facility for operating on light emitted from the plurality of LED light sources. The optical facility may include a phosphor for shifting a wavelength of light from one or more of the plurality of LEDs. The thermal facility may include an interior cavity of the housing for moving air within the housing, a vent for releasing air from an interior of the housing to an exterior of the housing, one or more fins for radiating heat from the housing, a heat-conducting mass integral to the housing, a potting facility for receiving heat from the circuit board, a metal plate or other thermal facility. The plurality of LEDs may include at least one high-brightness LED.  
      In the method, a lens may be disposed in a slot above the array wherein a profile of the lens may be co-planar with a top of the housing. The lens may be sealed to prevent a user from accessing the plurality of LEDs. A power facility may provide power to the plurality of LEDs. The power facility includes a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. The lighting unit may be a networked lighting unit. The lighting unit may be addressed using a serial addressing protocol. The lighting unit may be an addressable lighting unit. The lighting unit may be addressed using a determination algorithm.  
      In another aspect, a system disclosed herein includes providing a housing, the housing being substantially linear and the housing including a slot for receiving an array of a plurality of LED light sources, the plurality of LED light sources capable of producing substantially white light, and the array disposed on a circuit board within the housing; an interior power/data feed from a first end of the housing to a second end of the housing; at least one connector within at least one of the first end and the second end adapted to connect the lighting unit to a similar lighting unit while allowing the two lighting units to be placed end to end without spacing therebetween; and a thermal facility for removing heat from a proximity of the plurality of LED light sources.  
      In the system, the plurality of LED light sources may include one or more red LEDs, one or more green LEDs, one or more blue LEDs, and one or more white LEDs. The plurality of LED light sources may include at least two white LEDs that emit different color temperatures of white light. The plurality of LED light sources may include one or more blue LEDs that include a phosphor. The plurality of LED light sources may include at least one white LED and at least one amber LED. The plurality of LED light sources may include one or more ultraviolet LEDs and one or more phosphors. The lens may include an optical facility for operating on light emitted from the plurality of LED light sources. The optical facility may include a phosphor for shifting a wavelength of light from one or more of the plurality of LEDs. The thermal facility may include an interior cavity of the housing for moving air within the housing, a vent for releasing air from an interior of the housing to an exterior of the housing, one or more fins for radiating heat from the housing, a heat-conducting mass integral to the housing, a potting facility for receiving heat from the circuit board, a metal plate or other thermal facility. The plurality of LEDs may include at least one high-brightness LED.  
      In the system, a lens may be disposed in a slot above the array wherein a profile of the lens may be co-planar with a top of the housing. The lens may be sealed to prevent a user from accessing the plurality of LEDs. A power facility may provide power to the plurality of LEDs. The power facility includes a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. The lighting unit may be a networked lighting unit. The lighting unit may be addressed using a serial addressing protocol. The lighting unit may be an addressable lighting unit. The lighting unit may be addressed using a determination algorithm.  
      In one aspect, a method disclosed herein includes providing a circuit board; disposing a plurality of LEDs on the circuit board; and disposing a plurality of control facilities on the circuit board and connecting the plurality of control facilities in a series, each one of the control facilities controlling at least one of the plurality of LEDs, and each one of the control facilities being an addressable control facility that responds to data according to a serial addressing protocol.  
      In this method, one of the control facilities in the series may respond to a first unmodified byte in a data stream, modifies the first unmodified byte to provide a modified data stream, and sends the modified data stream to a next control facility in the series. Each one of the plurality of control facilities may be an application specific integrated circuit. Each one of the plurality of control facilities may control three LEDs. The three LEDs may be LEDs of three different colors. The three colors may be red, green and blue. The plurality of LEDs may substantially serve to illuminate a surrounding space or may be viewed directly.  
      In the method, the plurality of control facilities may be disposed in a rectangular array wherein the rectangular array may be a three-by-three array. The three-by-three array may have dimensions of about six inches by about six inches. The three-by-three array may have dimensions of about one foot by about one foot. The array may be a four-by-four array, a five-by-five array, a six-by-six array, or other array. The six-by-six array may have dimensions of about six inches by about six inches. The six-by-six array may have dimensions of about one foot by about one foot. A plurality of substantially rectangular circuit boards may contain substantially rectangular arrays of control facilities in an array of such rectangular circuit boards. The array of such rectangular circuit boards may be roughly spherical, roughly cylindrical, roughly semicylindrical, or other appropriate shape. A plurality of substantially triangular circuit boards may contain substantially triangular arrays of control facilities in an array of such triangular circuit boards. A protective lens may be for the circuit board. A lens may be fitted on the circuit board serving to shape the light coming from the LEDs. A diffuser may be fitted on the circuit serving to diffuse the light coming from the LEDs.  
      In another aspect, a device disclosed herein includes providing a plurality of LEDs disposed on the circuit board; and a plurality of control facilities disposed on the circuit board and connected in a series, each one of the plurality of control facilities being an addressable control facility adapted to control at least one of the plurality of LEDs and to respond to data according to a serial addressing protocol.  
      In this device, one of the control facilities in the series may respond to a first unmodified byte in a data stream, modifies the first unmodified byte to provide a modified data stream, and sends the modified data stream to a next control facility in the series. Each one of the plurality of control facilities may be an application specific integrated circuit. Each one of the plurality of control facilities may control three LEDs. The three LEDs may be LEDs of three different colors. The three colors may be red, green and blue. The plurality of LEDs may substantially serve to illuminate a surrounding space or may be viewed directly.  
      In this device, the plurality of control facilities may be disposed in a rectangular array wherein the rectangular array may be a three-by-three array. The three-by-three array may have dimensions of about six inches by about six inches. The three-by-three array may have dimensions of about one foot by about one foot. The array may be a four-by-four array, a five-by-five array, a six-by-six array, or other array. The six-by-six array may have dimensions of about six inches by about six inches. The six-by-six array may have dimensions of about one foot by about one foot. A plurality of substantially rectangular circuit boards may contain substantially rectangular arrays of control facilities in an array of such rectangular circuit boards. The array of such rectangular circuit boards may be roughly spherical, roughly cylindrical, roughly semicylindrical, or other appropriate shape. A plurality of substantially triangular circuit boards may contain substantially triangular arrays of control facilities in an array of such triangular circuit boards. A protective lens may be for the circuit board. A lens may be fitted on the circuit board serving to shape the light coming from the LEDs. A diffuser may be fitted on the circuit serving to diffuse the light coming from the LEDs.  
      In one aspect, there is disclosed herein a circuit board for a lighting system, as well as methods for providing such a circuit board, on which may be disposed a plurality of LEDs and a series of addressable control facilities, each of which may control at least one LED, wherein the control facility may respond to data according to an addressing protocol, which may be a serial protocol. A control facility in the series may respond to a first unmodified byte in a data stream; may modify that byte; and may send the modified data stream to the next control facility in the series. The control facility may be an application specific integrated circuit, which may control three LEDs. The control facilities may be individually addressable.  
      The three LEDs may be of three different colors which may, without limitation, be red, green, and blue. The LEDs may substantially serve to illuminate a surrounding space. Or, they may substantially service to be viewed directly.  
      The circuit board may be supplied with an interface for providing a physical connection and a data connection to another circuit board. The physical connection may be without limitation an interlocking tab configuration; a magnet; or a connector such as a jack. The physical connection may provide for the circuit board to interlocked with other such circuit boards to form an array. This interlocking may enable accurate and precise positioning of the LEDs, for example and without limitation by facilitating the production of a physical shape comprising a plurality of circuit boards. By individually addressing the addressable control facilities, it may be possible to create an appearance that differs from varying points of view.  
      In some embodiments, the circuit board may be triangular. Triangular circuit boards may be interlocked in such a manner as to create a substantially spherical configuration. This configuration may serve as a luminaire and may comprise without limitation narrow-angle LEDs; medium-angle LEDs; narrow- and medium-angle LEDs; or linear-emitting LEDs. The LEDs may point radially outward from the center of the spherical configuration.  
      Triangular circuit boards may be interlocked in a substantially cylindrical configuration. This configuration may serve as a luminaire and may comprise linear-emitting LEDs wherein the LEDs may point radially outward. Triangular circuit boards may be interlocked in a substantially a substantially semicylindrical configuration. This configuration may serve as a luminaire and may comprise linear-emitting LEDs wherein the LEDs may point inward, with the beams emitted by the LEDs crossing as they exit the half cylinder. Triangular circuit boards may be interlocked in an appreciably planar configuration. An edge of such an interlocking of triangular circuit boards may be connected to another configuration of circuit boards. Generally, triangular circuit boards may be interlocked to create a geometrical configuration that is planar such as a tesselation, that is three-dimensional and open such as a parabolic dish, or that is three-dimensional and volume-enclosing such as a sphere. The configuration may be connected on its surface or face to another such configuration.  
      In other embodiments, the circuit board may be rectangular. The control facilities may be disposed on a rectangular circuit board in a substantially rectangular array, which may without limitation be a three-by-three array; a four-by-four array; a five-by-five array; or a six-by-six array. In one embodiment, the array may have dimensions of about six inches by six inches. In another embodiment, the array may have dimensions of about one foot by one foot. Still other embodiments may become apparent from the following detailed description. In any case, a plurality of such rectangular circuit boards may themselves be disposed in an array. This array may be roughly spherical, roughly cylindrical, roughly semicylindrical, and so forth.  
      Generally, the circuit board may comprise a feature that may allow for like circuit boards to be connected. This connection may be in the same plane, or different planes. The different planes may intersect at any angle, including but not limited to a right angle. The feature that may allow for like circuit boards to be connected may comprise a magnetic facility, which may be disposed along the side of the circuit board; may provide a magnetic connection; may provide a power interface between the circuit board and another such circuit board; may provide a data interface between the circuit board and another such circuit board. The feature that may allow for like circuit boards to be connected may, alternately or additionally, comprise a fastening facility for allowing circuit boards to be connected, which may without limitation comprise a ball and socket combination; an adhesive; a tape; an interlocking shape; an interlocking edge; a tab; or a solderable finger joint. The circuit board may comprise a dedicated input pad and a dedicated output pad.  
      The circuit board may further comprise a protective cover, which may include a space providing a viewer with direct viewing of one of the LEDs without having light pass through the cover. The cover may be a sealed cover that may provide for underwater operation of the circuit board. The sealed cover may comprise a sealed housing, which may be oil-filled with an oil that may be clear, may serve as a thermal facility, may serve as an optical facility, may serve as both a thermal and optical facility, or may contain a non-conductive particulate, which may service to diffuse the light coming from the LEDs.  
      The circuit board may still further comprise a lens fitted on the printed circuit board serving to shape the light coming from the LEDs The lens may be interchangeable, such as a snap-in lense. Likewise, the circuit board may comprise a diffuser fitted on the circuit board serving to diffuse the light coming from the LEDs. The diffuser may be interchangeable, such as a snap-in diffuser  
      The circuit board may still yet further comprise a jack for taking in power and data from a source, such as and without limitation a central controller or another such circuit board. The circuit board may also comprise a jack for sending power and data out to a destination, such as and without limitation another such circuit board. The circuit board may still further comprise a Dipline-style mounting panel, which may allow the circuit board to be placed anywhere on a surface The circuit board may comprise an integrated hash mark or laser level for aligning the circuit board during installation and/or to facilitate accurate installation. A modular attached pin connector may providing contact between the circuit board and a selected conductive layer within a layered surface of conductors, such as a Dipline-style surface.  
      The circuit board may further comprise a sensor that is operatively coupled to the circuit board. The sensor may be disposed on the circuit board, coupled via a wire to the circuit board, or coupled via a wireless facility to the circuit board. The sensor may be without limitation a yaw sensor; a pitch sensor; a roll sensor; a two-axis sensor, wherein the two axes may be selected from the group of yaw, pitch, roll; a three-axis sensor, such as a roll, pitch, yaw sensor; a global positioning system; an inclinometer; a gyroscope; a sensor thaqt functions as though it is a gyroscope; an inertial navigation sensor; a dead reckoning device; or a sensor that detects motion.  
      The circuit board may be operatively coupled to a plurality of other such circuit boards, thus forming an array of circuit boards. The array of circuit boards may be attached to a wall with a mounting cleat, which may be disposed in proximity to a power supply; be disposed in proximity to a data supply; have an integrated electrical connection as well as power; comprise small ridges, which may provide electrical connection for both power and data, which may be shaped horizontally, or which may be shaped vertically.  
      The circuit board may further comprise an attachment to an electrical junction box, a thermally conductive gap pad to hold heat away from the LEDs, and/or an electrical rail. The electric rail may be a power rail or a data rail. A plurality of such rails may be provided in a grid format. The rail may serve as a track and the circuit board may snap into the track. The circuit board may further comprise providing live feedback during installation, such as and without limitation a blinking light or the emission of a particular color of light. The feedback may, without limitation be in relation to reaching a maximum number of units per power supply, the position of the circuit board with respect to another such circuit boards, or based upon a geometric orientation of the board. A sensor may measure the geometric orientation of the board.  
      A method disclosed herein includes providing a substantially flexible substrate; disposing a plurality of LEDs on the substrate; and providing a control facility on the substrate for controlling the plurality of LEDs.  
      In the method, the substrate may include a flexible band. A power facility may be provided for the plurality of LEDs. The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. A thermal facility may be provided for the circuit board. The thermal facility may include a potting compound. The thermal facility may include an epoxy.  
      In another aspect, a method disclosed herein includes providing a plurality of circuit boards, each circuit board having disposed thereon a plurality of LEDs and a control facility for controlling the plurality of LEDs; and providing a flexible connection between the circuit boards. The flexible connection may include an interlocking tab, a power/data connection, a data cable, a wire, or other connection type.  
      In another aspect, a lighting system disclosed herein includes a substantially flexible substrate; a plurality of LEDs on the substrate; and a control facility on the substrate for controlling the plurality of LEDs.  
      In the system, the substrate may include a flexible band. A power facility may be provided for the plurality of LEDs. The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, a power/data power facility, or other power facility. A thermal facility may be provided for the circuit board. The thermal facility may include a potting compound. The thermal facility may include an epoxy.  
      In another aspect, a flexible lighting system disclosed herein includes a plurality of circuit boards, each circuit board having disposed thereon a plurality of LEDs and a control facility for the plurality of LEDs; and a flexible connection between the circuit boards. The flexible connection may include an interlocking tab, a power/data connection, a data cable, a wire, or other connection type.  
      In another aspect, a method disclosed herein includes providing a circuit board, disposing a plurality of LEDs on the circuit board, and attaching an optical facility to the circuit board, the optical facility being an attachable optical facility.  
      In the method, the optical facility may include a lens. The lens may operate on light emitted from the plurality of LEDs. The optical facility may include a phosphor for shifting at least one wavelength of light emitted from the plurality of LEDs. The circuit board may be rectangular and the plurality of LEDs may be arranged in an array. The array may be a three-by-three array. The array may have dimensions of about six inches by about six inches. The array may have dimensions of about one foot by about one foot. The array may be a four-by-four array, a five-by-five array, a six-by-six array, or other array. The array may have dimensions of about six inches by about six inches. The array may have dimensions of about one foot by about one foot. The optical facility may include a diffuser. The optical facility may be transparent. The optical facility may include a hinge for attaching to the circuit board.  
      In another aspect, a system for providing an optical facility for a lighting unit may include a circuit board; a plurality of LEDs disposed on the circuit board; and an attachable optical facility for the circuit board.  
      In the system, the optical facility may include a lens. The lens may operate on light emitted from the plurality of LEDs. The optical facility may include a phosphor for shifting at least one wavelength of light emitted from the plurality of LEDs. The circuit board may be rectangular and the plurality of LEDs are arranged in an array. The array may be a three-by-three array. The array may have dimensions of about six inches by about six inches. The array may have dimensions of about one foot by about one foot. The array may be a four-by-four array, a five-by-five array, a six-by-six array, or other array. The array may have dimensions of about six inches by about six inches. The array may have dimensions of about one foot by about one foot. The optical facility may include a diffuser. The optical facility may be transparent. The optical facility may include a hinge for attaching to the circuit board.  
      In another aspect, a method disclosed herein includes providing a circuit board; disposing a plurality of LEDs on the circuit board; configuring the circuit board to be disposed in proximity to other similarly configured circuit boards; and providing a magnetic connector for connecting the circuit board to an item.  
      In the method, the item may be a second circuit board. The circuit board and the second circuit board may be magnetically connected and reside in substantially the same plane. The circuit board and the second circuit board may be magnetically connected and may bend relative to each other in different planes while remaining in physical connection. A data interface may be provided for allowing the circuit board to connect in a communicating relationship to another circuit board. The data interface may include the magnetic connector. The data interface may transceive data, carry power, include a ball and socket combination, include an adhesive, include a tape, include one or more interlocking shapes, include a tab, and/or include a solderable finger joint. An electrical path may provide identification to the circuit board. The identification may be transmitted to a controller on the circuit board. The identification may be transmitted through input and output pins of the circuit board.  
      In another aspect, a system disclosed herein includes a circuit board, the circuit board adapted to be disposed in proximity to other similarly configured circuit boards and to form a communicating relationship therewith; a plurality of LEDs disposed on the circuit board; and a magnetic connector for connecting the circuit board to an item.  
      In the system, the item may be a second circuit board. The circuit board and the second circuit board may be magnetically connected and may reside in substantially the same plane. The circuit board and the second circuit board may be magnetically connected and may bend relative to each other in different planes while remaining in physical connection. The system may include a data interface for allowing the circuit board to connect in a communicating relationship to another circuit board. The data interface may include the magnetic connector. The data interface may transceive data, carry power, include a ball and socket combination, include an adhesive, include a tape, include one or more interlocking shapes, include a tab, and/or include a solderable finger joint. An electrical path may provide identification to the circuit board. The identification may be transmitted to a controller on the circuit board. The identification may be transmitted through input and output pins of the circuit board.  
      In methods and systems disclosed herein, a lighting unit is provided that is shaped to fit to a fluorescent lighting fixture, wherein a plurality of LEDs are disposed on the structure, the LEDs being configured to receive power from a power facility. A fastening facility may be provided for connecting the structure to the fluorescent lighting fixture. The fastening facility may be without limitation a screw hole or a clip. The lighting unit may without limitation provide a thermal connection between the structure and the fluorescent lighting unit, may provide a data facility for delivering data to the LEDs, and may associate a control facility with each of the LEDs.  
      In these methods and systems, the LEDs may be light sources, which maybe configured to produce substantially white light and may include without limitation red, green, blue and white LEDs. The white LEDs may emit at different color temperatures of white light, may include blue LEDs that include a phosphor, may include at least one white LED and at least one amber LED, and/or may include a UV LED and a phosphor. The structure may be configured to fit over a fluorescent lamp, and may be a bridge-type structure with a substantially rectangular plane supported by two substantially rectangular legs, which may include two substantially rectangular planes connected at about a ninety-degree angle. In this configuration, the structure may be configured to fit between the ballasts that receive a fluorescent lamp, wherein the power facility may be configured to receive power from the ballasts that power the fluorescent lamp. In an alternate configuration, the structure may comprise three substantially rectangular sides, two of which may be substantially parallel to each other, the third of which may be perpendicular to the first two and connects the first two. The lighting unit may comprise a power facility for the lighting unit, which may without limitation be a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, or a power/data power facility. The lighting unit may be a networked lighting unit. The lighting unit may further comprise a thermal facility for the lighting unit, wherein the thermal facility may without limitation be an interior cavity of the lighting unit for moving air within the housing, a vent for releasing air from the interior of the housing to the exterior of the housing, a fin for radiating heat from the housing, a heat-conducting mass that is part of the housing, a potting facility for receiving heat from the board, and/or a metal plate.  
      In certain embodiments, a method of providing a lighting unit disclosed herein includes providing a structure that is shaped to fit into an incandescent lighting fixture; and disposing a plurality of LEDs on the structure, the LEDs configured to receive power from a power facility.  
      The method may further include providing a fastening facility for connecting the structure to the incandescent lighting fixture. The fastening facility may include a screw hole. The fastening facility may include a clip. The method may further include providing a thermal connection. The method may further include providing a data facility for delivering data to the plurality of LEDs. The method may further include associating a control facility with each one of the plurality of LEDs. The plurality of LEDs may be configured to produce substantially white light. The plurality of LEDs may include at least one red LED, at least one green LED, and least one blue LED, and at least one white LED. The plurality of LEDs may include at least two white LEDs that emit light at different color temperatures of white light. The plurality of LEDs may include at least one blue LED that further includes a phosphor. The plurality of LEDs may include at least one white LED and at least one amber LED. The plurality of LEDs may include at least one ultraviolet LED, the ultraviolet LED including a phosphor.  
      The structure may be configured to fit over an incandescent light bulb. The structure may be a bridge-type structure with a substantially rectangular plane supported by two substantially rectangular legs. The structure may include two substantially rectangular planes connected at about a ninety degree angle. The structure may be a substantially cylindrical structure with a substantially circular top. The structure may have three substantially rectangular sides, two of which are substantially parallel to each other, the third of which is perpendicular to the first two and connects the first two.  
      The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, and/or a power/data power facility. The lighting unit may be a networked lighting unit. The method may further include providing a thermal facility for the lighting unit. The thermal facility may include a heat-conducting path for connecting the structure that supports the plurality of LEDs to the housing of the incandescent lighting fixture. The heat-conducting path may connect to a socket for an incandescent bulb. The heat-conducting path may include a flare shape that touches a housing of an incandescent lighting unit. The thermal facility may include an interior cavity of the structure for moving air within the structure, a vent for releasing air from an interior of the structure to an exterior of the structure, at least one fin for radiating heat from the structure, a heat-conducting mass integral to the structure, a potting facility for receiving heat from a circuit board associated with one or more of the plurality of LEDs, and/or a metal plate.  
      In another aspect, a lighting unit disclosed herein includes a structure shaped to fit to an incandescent lighting fixture; and a plurality of LEDs on the structure, the LEDs being adapted to receive power from a power facility.  
      The lighting unit may further include a fastening facility for connecting the structure to the incandescent lighting fixture. The fastening facility may include a screw hole. The fastening facility may include a clip. The lighting unit may further include a thermal connection. The lighting unit may further include a data facility for delivering data to the plurality of LEDs. The lighting unit may further include a control facility associated with each one of the plurality of LEDs. The plurality of LEDs may be configured to produce substantially white light. The plurality of LEDs may include at least one red LED, at least one green LED, and least one blue LED, and at least one white LED. The plurality of LEDs may include at least two white LEDs that emit light at different color temperatures of white light. The plurality of LEDs may include at least one blue LED that further includes a phosphor. The plurality of LEDs may include at least one white LED and at least one amber LED. The plurality of LEDs may include at least one ultraviolet LED, the ultraviolet LED including a phosphor.  
      The structure may be configured to fit over an incandescent light bulb. The structure may be a bridge-type structure with a substantially rectangular plane supported by two substantially rectangular legs. The structure may include two substantially rectangular planes connected at about a ninety degree angle. The structure may be a substantially cylindrical structure with a substantially circular top. The structure may have three substantially rectangular sides, two of which are substantially parallel to each other, the third of which is perpendicular to the first two and connects the first two.  
      The power facility may include a high-voltage power facility, a power-factor-corrected power facility, an on-board power facility, an inductively controlled power facility, a feed-forward power facility, and/or a power/data power facility. The lighting unit may be a networked lighting unit. The lighting unit may further include a thermal facility for the lighting unit. The thermal facility may include a heat-conducting path for connecting the structure that supports the plurality of LEDs to the housing of the incandescent lighting fixture. The heat-conducting path may connect to a socket for an incandescent bulb. The heat-conducting path may include a flare shape that touches a housing of an incandescent lighting unit. The thermal facility may include an interior cavity of the structure for moving air within the structure, a vent for releasing air from an interior of the structure to an exterior of the structure, at least one fin for radiating heat from the structure, a heat-conducting mass integral to the structure, a potting facility for receiving heat from a circuit board associated with one or more of the plurality of LEDs, and/or a metal plate.  
      In one aspect, a device disclosed herein includes a housing configured to fit a lighting fixture, the lighting fixture being a conventional lighting fixture, and the housing shaped to cover a space where a conventional bulb would be located in the lighting fixture; a plurality of light sources associated with the housing, the plurality of light sources generating heat in response to activation; a thermal facility that dissipates heat from the plurality of light sources; and a fastener adapted to attach the housing to the lighting fixture.  
      The fastener may include at least one of a screw hole, a clip, or a tab. The fastener may provide a heat conduction path for the thermal facility. The device may include a circuit board associated with one or more of the plurality of light sources. The thermal facility may include a heat-conducting plate associated with the circuit board. The housing may be cylindrical. The device may include a processor to control operation of the plurality of light sources. The plurality of light sources may include at least one LED. The plurality of light sources may be disposed on top of the housing. The light fixture may include at least one ballast. The light fixture may include a diffuser that diffuses light emitted from the plurality of light sources. The light sources may be arranged in one or more lines. The fixture may include a socket for at least one of an incandescent lamp or a halogen lamp. The device may include an optical facility. The optical facility may include a protective cover for at least one of the plurality of light sources and one or more electrical components associated with the plurality of light sources.  
      In another aspect, a method disclosed herein includes providing a housing configured to fit a lighting fixture, the lighting fixture being a conventional lighting fixture, and the housing shaped to cover a space where a conventional bulb would be located in the lighting fixture; associating a plurality of light sources with the housing, the plurality of light sources generating heat in response to activation; placing a thermal facility in thermally conductive association with the plurality of light sources to dissipate heat from the plurality of light sources when the plurality of light sources are activated; and providing a fastener adapted to attach the housing to the lighting fixture.  
      The fastener may include at least one of a screw hole, a clip, or a tab. The fastener may provide a heat conduction path for the thermal facility. The method may include mounting the plurality of light sources on a circuit board. The thermal facility may include a heat-conducting plate associated with the circuit board. The housing may be cylindrical. The method may include controlling operation of the plurality of light sources with a processor. The plurality of light sources may include at least one LED. The plurality of light sources may be disposed on top of the housing. The light fixture may include at least one ballast. The method may include diffusing light emitted from the plurality of light sources. The method may include arranging the light sources in one or more lines. The fixture may include a socket for at least one of an incandescent lamp or a halogen lamp. The method may include associating an optical facility with the light sources. The optical facility may include a protective cover for at least one of the plurality of light sources and one or more electrical components associated with the plurality of light sources.  
      In another aspect, a method of providing a lighting structure as disclosed herein includes providing a structural element for bearing a plurality of LEDs; and providing a control facility for controlling the LEDs, wherein the structural element is configured to fit with other structural elements into the lighting structure.  
      In the method, the structural element may be designed to allow tessellation of multiple structural elements. The structural element may be designed to allow tiling of structural elements filling a portion of a two-dimensional plane. The structural element may be a triangle. The structural element may be an icosahedron. The structural element may be a six-sided element. The structural element may be designed to facilitate construction of a spherical lighting structure. The structural element may be designed to facilitate construction of a two-dimensional lighting structure. The structural element may include a power facility. The power facility may be a high-voltage power facility. The power facility may be a power-factor-corrected power facility. The power facility may be an on-board power facility. The power facility may be an inductively controlled power facility. The power facility may be a feed-forward power facility. The power facility may be a power/data power facility. The structural element may be a networked lighting unit. The structural element may be addressed using a serial addressing protocol. The structural element may be designed to facilitate construction of a rectangular solid lighting structure.  
      In another aspect, a system for a lighting structure as disclosed herein may include: a structural element for bearing a plurality of LEDs; and a control facility for controlling the LEDs, wherein the structural element is configured to fit with other structural elements into the lighting structure.  
      In the system, the structural element may be designed to allow tessellation of multiple structural elements. The structural element may be designed to allow tiling of structural elements filling a portion of a two-dimensional plane. The structural element may be a triangle. The structural element may be an icosahedron. The structural element may be a six-sided element. The structural element may be designed to facilitate construction of a spherical lighting structure. The structural element may be designed to facilitate construction of a two-dimensional lighting structure. The structural element may include a power facility. The power facility may be a high-voltage power facility. The power facility may be a power-factor-corrected power facility. The power facility may be an on-board power facility. The power facility may be an inductively controlled power facility. The power facility may be a feed-forward power facility. The power facility may be a power/data power facility. The structural element may be a networked lighting unit. The structural element may be addressed using a serial addressing protocol. The structural element may be designed to facilitate construction of a rectangular solid lighting structure.  
      A method of providing an effect on a lighting system disclosed herein may include: distributing a plurality of lighting units in a geometric configuration, each of the lighting units being an addressable lighting unit; mapping a plurality of addresses corresponding to the plurality of lighting units; providing a control facility for controlling the plurality of lighting units using the plurality of addresses; providing an authoring facility for authoring an effect; and using the authoring facility to generate a scrolling effect on the lighting system, the scrolling effect using the plurality of addresses to map control signals to the locations of selected ones of the plurality of lighting units in the geometric configuration.  
      In the method, the scrolling effect may be a text effect. The scrolling effect may be an animation effect. The lighting units may be individually addressable. The lighting units may be addressable strings of lighting units. The strings may be flexible. The strings may be disposed as a curtain. The strings may be woven into a fabric. The strings may be disposed on an exterior of a building. The strings may be disposed on a wall of an interior of a building. The lighting units may be disposed in a non-rectangular configuration.  
      In another aspect, a system disclosed herein may include a plurality of lighting units in a geometric configuration, each one of the plurality of lighting units having an address and a predetermined location within the geometric configuration; an address mapping of each address of one of the plurality of lighting units to the predetermined location of that one of the plurality of lighting units; a control facility for controlling the lighting units, the control facility configured to access each one of the plurality of lighting units by address; and an authoring facility for authoring an effect including a scrolling effect by applying the address mapping to map actions in a user interface to lighting control signals for selected ones of the plurality of lighting units in the geometric configuration.  
      In the system, the scrolling effect may be a text effect. The scrolling effect may be an animation effect. The lighting units may be individually addressable. The lighting units may be addressable strings of lighting units. The strings may be flexible. The strings may be disposed as a curtain. The strings may be woven into a fabric. The strings may be disposed on an exterior of a building. The strings may be disposed on a wall of an interior of a building. The lighting units may be disposed in a non-rectangular configuration.  
      In one aspect, a method of providing a lighting system as disclosed herein includes providing a plurality of LEDs; providing a control facility for the LEDs; and disposing the LEDs and the control facility in a housing, the housing configured to hold an on-board power facility.  
      In the method, the power facility may include a high-voltage power facility. The power facility may include a power-factor-corrected power facility. The power facility may include an inductively controlled power facility. The power facility may include a feed-forward power facility. The power facility may include a power/data power facility. The lighting system may include an architectural lighting fixture. The lighting system may include a theatrical lighting system. The lighting system may include a lighting system for a transportation environment. The lighting system may include a general illumination lighting system for a venue. The venue may include an entertainment venue. The venue may include a restaurant. The venue may include a nightclub. The venue may include an office. The venue may include an outdoor lighting system for an exterior of a building. The lighting system may include a lighting system for a large-scale display. The lighting system may include an alcove lighting system. The lighting system may include a wall washing lighting system.  
      In another aspect, a lighting system disclosed herein may include a housing configured to hold an on-board power facility; a plurality of LEDs disposed in the housing; and a control facility disposed in the housing, the control facility configured to control operation of the plurality of LEDs.  
      In the system, the power facility may include a high-voltage power facility. The power facility may include a power-factor-corrected power facility. The power facility may include an inductively controlled power facility. The power facility may include a feed-forward power facility. The power facility may include a power/data power facility. The lighting system may include an architectural lighting fixture. The lighting system may include a theatrical lighting system. The lighting system may include a lighting system for a transportation environment. The lighting system may include a general illumination lighting system for a venue. The venue may include an entertainment venue. The venue may include a restaurant. The venue may include a nightclub. The venue may include an office. The venue may include an outdoor lighting system for an exterior of a building. The lighting system may include a lighting system for a large-scale display. The lighting system may include an alcove lighting system. The lighting system may include a wall washing lighting system.  
      The following patents and patent applications are hereby incorporated herein by reference:  
      U.S. Pat. No. 6,016,038, issued Jan. 18, 2000, entitled “Multicolored LED Lighting Method and Apparatus;” 
      U.S. Pat. No. 6,211,626, issued Apr. 3, 2001 to Lys et al, entitled “Illumination Components,” 
      U.S. Pat. No. 6,608,453, issued Aug. 19, 2003, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” 
      U.S. Pat. No. 6,548,967, issued Apr. 15, 2003, entitled “Universal Lighting Network Methods and Systems;” 
      U.S. patent application Ser. No. 09/886,958, filed Jun. 21, 2001, entitled Method and Apparatus for Controlling a Lighting System in Response to an Audio Input;” 
      U.S. patent application Ser. No. 10/078,221, filed Feb. 19, 2002, entitled “Systems and Methods for Programming Illumination Devices;” 
      U.S. patent application Ser. No. 09/344,699, filed Jun. 25, 1999, entitled “Method for Software Driven Generation of Multiple Simultaneous High Speed Pulse Width Modulated Signals;” 
      U.S. patent application Ser. No. 09/805,368, filed Mar. 13, 2001, entitled “Light-Emitting Diode Based Products;” 
      U.S. patent application Ser. No. 09/716,819, filed Nov. 20, 2000, entitled “Systems and Methods for Generating and Modulating Illumination Conditions;” 
      U.S. patent application Ser. No. 09/675,419, filed Sep. 29, 2000, entitled “Systems and Methods for Calibrating Light Output by Light-Emitting Diodes;” 
      U.S. patent application Ser. No. 09/870,418, filed May 30, 2001, entitled “A Method and Apparatus for Authoring and Playing Back Lighting Sequences;” 
      U.S. patent application Ser. No. 10/045,604, filed Mar. 27, 2003, entitled “Systems and Methods for Digital Entertainment;” 
      U.S. patent application Ser. No. 10/045,629, filed Oct. 25, 2001, entitled “Methods and Apparatus for Controlling Illumination;” 
      U.S. patent application Ser. No. 09/989,677, filed Nov. 20, 2001, entitled “Information Systems;” 
      U.S. patent application Ser. No. 10/158,579, filed May 30, 2002, entitled “Methods and Apparatus for Controlling Devices in a Networked Lighting System;” 
      U.S. patent application Ser. No. 10/163,085, filed Jun. 5, 2002, entitled “Systems and Methods for Controlling Programmable Lighting Systems;” 
      U.S. patent application Ser. No. 10/174,499, filed Jun. 17, 2002, entitled “Systems and Methods for Controlling Illumination Sources;” 
      U.S. patent application Ser. No. 10/245,788, filed Sep. 17, 2002, entitled “Methods and Apparatus for Generating and Modulating White Light Illumination Conditions;” 
      U.S. patent application Ser. No. 10/245,786, filed Sep. 17, 2002, entitled “Light Emitting Diode Based Products;” 
      U.S. patent application Ser. No. 10/325,635, filed Dec. 19, 2002, entitled “Controlled Lighting Methods and Apparatus;” 
      U.S. patent application Ser. No. 10/360,594, filed Feb. 6, 2003, entitled “Controlled Lighting Methods and Apparatus;” 
      U.S. patent application Ser. No. 10/435,687, filed May 9, 2003, entitled “Methods and Apparatus for Providing Power to Lighting Devices;” and  
      U.S. patent application Ser. No. 10/828,933, filed Apr. 21, 2004, entitled “Tile Lighting Methods and Systems.” 
      It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  depicts a configuration for a controlled lighting system.  
       FIG. 2  is a schematic diagram with elements for a lighting system.  
       FIG. 3  depicts configurations of light sources that can be used in a lighting system.  
       FIG. 4  depicts an optical facility for a lighting system.  
       FIG. 5  depicts diffusers that can serve as optical facilities.  
       FIG. 6  depicts optical facilities.  
       FIG. 7  depicts optical facilities for lighting systems.  
       FIG. 8  depicts a tile light housing for a lighting system.  
       FIG. 9  depicts housings for architectural lighting systems.  
       FIG. 10  depicts specialized housings for lighting systems.  
       FIG. 11  depicts housings for lighting systems.  
       FIG. 12  depicts a signage housing for a lighting system.  
       FIG. 13  depicts a housing for a retrofit lighting unit.  
       FIGS. 14   a - d  depict housings for a linear fixture.  
       FIG. 15  depicts a power circuit for a lighting system with power factor correction.  
       FIG. 16  depicts another embodiment of a power factor correction power system.  
       FIG. 17  depicts another embodiment of a power system for a lighting system that includes power factor correction.  
       FIG. 18  depicts drive hardware for a lighting system.  
       FIG. 19  depicts thermal facilities for a lighting system.  
       FIG. 20  depicts mechanical interfaces for lighting systems.  
       FIG. 21  depicts additional mechanical interfaces for lighting systems.  
       FIGS. 22   a - d  depict additional mechanical interfaces for a lighting system.  
       FIG. 23  depicts a mechanical interface for connecting two linear lighting units.  
       FIG. 24  depicts drive hardware for a lighting system.  
       FIG. 25  depicts methods for driving lighting systems.  
       FIG. 26  depicts a chromaticity diagram for a lighting system.  
       FIG. 27  depicts a configuration for a light system manager.  
       FIG. 28  depicts a configuration for a networked lighting system.  
       FIG. 29  depicts an XML parser environment for a lighting system.  
       FIG. 30  depicts a network with a central control facility for a lighting system.  
       FIG. 31  depicts network topologies for lighting systems.  
       FIG. 32  depicts a physical data interface for a lighting system with a communication port.  
       FIG. 33  depicts physical data interfaces for lighting systems.  
       FIG. 34  depicts user interfaces for lighting systems.  
       FIG. 35  depicts additional user interfaces for lighting systems.  
       FIG. 36  depicts a keypad user interface.  
       FIG. 37  depicts a configuration file for mapping locations of lighting systems.  
       FIG. 38  depicts a binary tree for a method of addressing lighting units.  
       FIG. 39  depicts a flow diagram for mapping locations of lighting units.  
       FIG. 40  depicts steps for mapping lighting units.  
       FIG. 41  depicts a method for mapping and grouping lighting systems for purposes of authoring shows.  
       FIG. 42  depicts a graphical user interface for authoring lighting shows.  
       FIG. 43  depicts a user interface screen for an authoring facility.  
       FIG. 44  depicts effects and meta effects for a lighting show.  
       FIG. 45  depicts steps for converting an animation into a set of lighting control signals.  
       FIG. 46  depicts steps for associating lighting control signals with other object-oriented programs.  
       FIG. 47  depicts parameters for effects.  
       FIG. 48  depicts effects that can be created using lighting systems.  
       FIG. 49  depicts additional effects.  
       FIG. 50  depicts additional effects.  
       FIG. 51  depicts environments for lighting systems.  
       FIG. 52  depicts additional environments for lighting systems.  
       FIG. 53  depicts additional environments for lighting systems.  
       FIG. 54  depicts additional environments for lighting systems.  
       FIG. 55  depicts additional environments for lighting systems.  
       FIG. 56  depicts a retrofit housing for a linear fixture.  
       FIG. 57  depicts an embodiment of a retrofit housing for a linear fixture.  
       FIG. 58  depicts an embodiment of a retrofit housing for a cylindrical fixture.  
       FIG. 59  depicts a retrofit housing for a linear fixture.  
       FIG. 60  depicts a bottom view of a retrofit housing for a linear fixture.  
       FIG. 61  depicts a retrofit unit disposed over a ballast for a fluorescent fixture.  
       FIG. 62  depicts a retrofit unit disposed over a ballast for a fluorescent fixture.  
       FIG. 63  depicts a retrofit unit for a hanging light fixture.  
       FIG. 64  depicts a retrofit unit for a down light fixture.  
       FIG. 65  depicts a board designed to fit on a substantially rectangular fixture.  
       FIG. 66  depicts a retrofit unit for a traditional lighting fixture.  
       FIG. 67  depicts a lighting unit with two perpendicular planes.  
       FIG. 68  depicts a lighting unit with power and data supplied to both ends of the unit.  
       FIG. 69  depicts a lighting unit with power and data supplied to one end of the unit.  
       FIG. 70  depicts a flared thermal facility for a lighting unit.  
       FIG. 71  depicts a cylindrical lighting unit with a thermal facility.  
       FIG. 72  depicts a lighting unit with three sides.  
       FIG. 73  depicts a cover for an array of LEDs on a board, where the cover includes optical elements.  
       FIG. 74  depicts boards with magnetic interconnections.  
       FIGS. 75 and 76  depict boards with interlocking connectors.  
       FIG. 77  depicts a board with a motion sensor.  
       FIG. 78  depicts a board with an attachable optical lens element.  
       FIG. 79  depicts a lighting unit formed as a modular block.  
       FIG. 80  depicts a lighting unit formed on flexible circuit board material.  
       FIG. 81  depicts a cleat-type mounting for an array-type lighting unit. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 1 , in a lighting system  100  a lighting unit  102  is controlled by a control facility  3500 . In embodiments, the control facility  3500  controls the intensity, color, saturation, color temperature, on-off state, brightness, or other feature of light that is produced by the lighting unit  102 . The lighting unit  102  can draw power from a power facility  1800 . The lighting unit  102  can include a light source  300 , which in embodiments is a solid-state light source, such as a semiconductor-based light source, such as light emitting diode, or LED.  
      Referring to  FIG. 2 , the system  100  can be a solid-state lighting system and can include the lighting unit  102  as well as a wide variety of optional control facilities  3500 .  
      In embodiments, the system  100  may include an electrical facility  202  for powering and controlling electrical input to the light sources  300 , which may include drive hardware  3802 , such as circuits and similar elements, and the power facility  1800 .  
      In embodiments the system can include a mechanical interface  3200  that allows the lighting unit  102  to mechanically connect to other portions of the system  100 , or to external components, products, lighting units, housings, systems, hardware, or other items.  
      The lighting unit  102  may have a primary optical facility  1700 , such as a lens, mirror, or other optical facility for shaping beams of light that exit the light source, such as photons exiting the semiconductor in an LED package  
      The system  100  may include an optional secondary optical facility  400 , which may diffuse, spread, focus, filter, diffract, reflect, guide or otherwise affect light coming from a light source  300 . The secondary optical facility  400  may include one or many elements.  
      In embodiments, the light sources  300  may be disposed on a support structure, such as a board  204 . The board  204  may be a circuit board or similar facility suitable for holding light sources  300  as well as electrical components, such as components used in the electrical facility  202 .  
      In embodiments the system  100  may include a thermal facility  2500 , such as a heat-conductive plate, metal plate, gap pad, liquid heat-conducting material, potting facility, fan, vent, or other facility for removing heat from the light sources  300 .  
      The system  100  may optionally include a housing  800 , which in embodiments may hold the board  204 , the electrical facility  202 , the mechanical interface  3200 , and the thermal facility  2500 . In some embodiments, no housing  800  is present.  
      In embodiments the system  100  is a standalone system with an on-board control facility  3500 . The system  100  can include a processor  3600  for processing data to accept control instructions and to control the drive hardware  3802 .  
      In embodiments the system  100  can respond to control of a user interface  4908 , which may provide control directly to the lighting unit  102 , such as through a switch, dial, button, dipswitch, slide mechanism, or similar facility or may provide control through another facility, such as a network interface  4902 , a light system manager  5000 , or other facility.  
      The system  100  can include a data storage facility  3700 , such as memory. In a standalone embodiment the data storage facility  3700  may be memory, such as random access memory. In other embodiments the data storage facility  3700  may include any other facility for storing and retrieving data.  
      The system  100  can produce effects  9200 , such as illumination effects  9300  that illuminate a subject  9900  and direct view effects  9400  where the viewer is intended to view the light sources  300  or the secondary optical facility  400  directly, in contrast to viewing the illumination produced by the light sources  300 , as in illumination effects  9300 . Effects can be static and dynamic, including changes in color, color-temperature, intensity, hue, saturation and other features of the light produced by the light sources  300 . Effects from lighting units  102  can be coordinated with effects from other systems, including other lighting units  102 .  
      The system  100  can be disposed in a wide variety of environments  9600 , where effects  9200  interact with aspects of the environments  9600 , such as subjects  9900 , objects, features, materials, systems, colors or other characteristics of the environments. Environments  9600  can include interior and exterior environments, architectural and entertainment environments, underwater environments, commercial environment, industrial environments, recreational environments, home environments, transportation environments and many others.  
      Subjects  9900  can include a wide range of subjects  9900 , ranging from objects such as walls, floors and ceilings to alcoves, pools, spas, fountains, curtains, people, signs, logos, buildings, rooms, objects of art and photographic subjects, among many others.  
      While embodiments of a control facility  3500  may be as simple as a single processor  3600 , data storage facility  3700  and drive hardware  3802 , in other embodiments more complex control facilities  3500  are provided. Control facilities may include more complex drive facilities  3800 , including various forms of drive hardware  3802 , such as switches, current sinks, voltage regulators, and complex circuits, as well as various methods of driving  4300 , including modulation techniques such as pulse-width-modulation, pulse-amplitude-modulation, combined modulation techniques, table-based modulation techniques, analog modulation techniques, and constant current techniques. In embodiments a control facility  3500  may include a combined power/data protocol  4800  for controlling light sources  300  in response to data delivered over power lines.  
      A control facility  3500  may include a control interface  4900 , which may include a physical interface  4904  for delivering data to the lighting unit  102 . The control interface  4900  may also include a computer facility, such as a light system manager  5000  for managing the delivery of control signals, such as for complex shows and effects  9200  to lighting units  102 , including large numbers of lighting units  102  deployed in complex geometric configurations over large distances.  
      The control interface  4900  may include a network interface  4902 , such as for handling network signals according to any desired network protocol, such as DMX, Ethernet, TCP/IP, DALI, 802.11 and other wireless protocols, and linear addressing protocols, among many others. In embodiments the network interface  4902  may support multiple protocols for the same lighting unit  102 .  
      In embodiments involving complex control, the physical data interface  4904  may include suitable hardware for handling data transmissions, such as USB ports, serial ports, Ethernet facilities, wires, routers, switches, hubs, access points, buses, multi-function ports, intelligent sockets, intelligent cables, flash and USB memory devices, file players, and other facilities for handling data transfers.  
      In embodiments the control facility  3500  may include an addressing facility  6600 , such as for providing an identifier or address to one or more lighting units  102 . Many kinds of addressing facility  6600  may be used, including facilities for providing network addresses, dipswitches, bar codes, sensors, cameras, and many others.  
      In embodiments the control facility  3500  may include an authoring facility  7400  for authoring effects  9200 , including complex shows, static and dynamic effects. The authoring facility  7400  may be associated with the light system manager  5000 , such as to facilitate delivery of control signals for complex shows and effects over a network interface  4900  to one or more lighting units  102 . The authoring facility  7400  may include a geometric authoring facility, an interface for designing light shows, an object-oriented authoring facility, an animation facility, or any of a variety of other facilities for authoring shows and effects.  
      In embodiments the control facility  3500  may take input from a signal sources  8400 , such as a sensor  8402 , an information source, a light system manager  5000 , a user interface  4908 , a network interface  4900 , a physical data interface  4904 , an external system  8800 , or any other source capable of producing a signal.  
      In embodiments the control facility  3500  may respond to an external system  8800 . The external system  8800  may be a computer system, an automation system, a security system, an entertainment system, an audio system, a video system, a personal computer, a laptop computer, a handheld computer, or any of a wide variety of other systems that are capable of generating control signals.  
      Referring to  FIG. 3 , the lighting unit  102  may be any kind of lighting unit  102  that is capable of responding to control, but in embodiments the lighting unit  102  includes a light source  300  that is a solid-state light source, such as a semiconductor-based light source, such as a light emitting diode, or LED. Lighting units  102  can include LEDs that produce a single color or wavelength of light, or LEDs that produce different colors or wavelengths, including red, green, blue, white, orange, amber, ultraviolet, infrared, purple or any other wavelength of light. Lighting units  102  can include other light sources, such as organic LEDS, or OLEDs, light emitting polymers, crystallo-luminescent lighting units, lighting units that employ phosphors, luminescent polymers and other sources. In other embodiments, lighting units  102  may include incandescent sources, halogen sources, metal halide sources, fluorescent sources, compact fluorescent sources and others.  
      Referring still to  FIG. 3 , the sources  300  can be point sources or can be arranged in many different configurations  302 , such as a linear configuration  306 , a circular configuration  308 , an oval configuration  304 , a curvilinear configuration, or any other geometric configuration, including two-dimensional and three-dimensional configurations. The sources  300  can also be mixed, including sources  300  of varying wavelength, intensity, power, quality, light output, efficiency, efficacy or other characteristics. In embodiments sources  300  for different lighting units  102  are consistently mixed to provide consistent light output for different lighting units  102 . In embodiments the sources are mixed  300  to allow light of different colors or color temperatures, including color temperatures of white. Various mixtures of sources  300  can produce substantially white light, such as mixtures of red, green and blue LEDs, single white sources  300 , two white sources of varying characteristics, three white sources of varying characteristics, or four or more white sources of varying characteristics. One or more white source can be mixed with, for example, an amber or red source to provide a warm white light or with a blue source to produce a cool white light.  
      Sources  300  may be constructed and arranged to produce a wide range of variable color radiation. For example, the source  300  may be particularly arranged such that the processor-controlled variable intensity light generated by two or more of the light sources combines to produce a mixed colored light (including essentially white light having a variety of color temperatures). In particular, the color (or color temperature) of the mixed colored light may be varied by varying one or more of the respective intensities of the light sources or the apparent intensities, such as using a duty cycle in a pulse width modulation technique. Combinations of LEDs with other mechanisms that affect light characteristics, such as phosphors, are also encompassed herein.  
      Any combination of LED colors can produce a gamut of colors, whether the LEDs are red, green, blue, amber, white, orange, UV, or other colors. The various embodiments described throughout this specification encompass all possible combinations of LEDs in lighting units  102 , so that light of varying color, intensity, saturation and color temperature can be produced on demand under control of a control facility  3500 .  
      Although mixtures of red, green and blue have been proposed for light due to their ability to create a wide gamut of additively mixed colors, the general color quality or color rendering capability of such systems are not ideal for all applications. This is primarily due to the narrow bandwidth of current red, green and blue emitters. However, wider band sources do make possible good color rendering, as measured, for example, by the standard CRI index. In some cases this may require LED spectral outputs that are not currently available. However, it is known that wider-band sources of light will become available, and such wider-band sources are encompassed as sources for lighting units  102  described herein.  
      Additionally, the addition of white LEDs (typically produced through a blue or UV LED plus a phosphor mechanism) does give a ‘better’ white, but it still can be limiting in the color temperature that is controllable or selectable from such sources.  
      The addition of white to a red, green and blue mixture may not increase the gamut of available colors, but it can add a broader-band source to the mixture. The addition of an amber source to this mixture can improve the color still further by ‘filling in’ the gamut as well.  
      Combinations of light sources  300  can help fill in the visible spectrum to faithfully reproduce desirable spectrums of lights. These include broad daylight equivalents or more discrete waveforms corresponding to other light sources or desirable light properties. Desirable properties include the ability to remove pieces of the spectrum for reasons that may include environments where certain wavelengths are absorbed or attenuated. Water, for example tends to absorb and attenuate most non-blue and non-green colors of light, so underwater applications may benefit from lights that combine blue and green sources  300 .  
      Amber and white light sources can offer a color temperature selectable white source, wherein the color temperature of generated light can be selected along the black body curve by a line joining the chromaticity coordinates of the two sources. The color temperature selection is useful for specifying particular color temperature values for the lighting source.  
      Orange is another color whose spectral properties in combination with a white LED-based light source can be used to provide a controllable color temperature light from a lighting unit  102 .  
      As used herein for purposes of the present disclosure, the term “LED” should be understood to include any light emitting diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, light-emitting strips, electro-luminescent strips, and the like.  
      In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured to generate radiation having various bandwidths for a given spectrum (e.g., narrow bandwidth, broad bandwidth).  
      For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectrums of luminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts luminescence having a first spectrum to a different second spectrum. In one example of this implementation, luminescence having a relatively short wavelength and narrow bandwidth spectrum “pumps” the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum.  
      It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectrums of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc.  
      The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources as defined above, incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of luminescent sources, electro-lumiscent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers.  
      A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms “light” and “radiation” are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication and/or illumination. An “illumination source” is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space.  
      The term “spectrum” should be understood to refer to any one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term “spectrum” refers to frequencies (or wavelengths) not only in the visible range, but also frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Also, a given spectrum may have a relatively narrow bandwidth (essentially few frequency or wavelength components) or a relatively wide bandwidth (several frequency or wavelength components having various relative strengths). It should also be appreciated that a given spectrum may be the result of a mixing of two or more other spectrums (e.g., mixing radiation respectively emitted from multiple light sources).  
      For purposes of this disclosure, the term “color” is used interchangeably with the term “spectrum.” However, the term “color” generally is used to refer primarily to a property of radiation that is perceivable by an observer (although this usage is not intended to limit the scope of this term). Accordingly, the terms “different colors” implicitly refer to different spectrums having different wavelength components and/or bandwidths. It also should be appreciated that the term “color” may be used in connection with both white and non-white light.  
      The term “color temperature” generally is used herein in connection with white light, although this usage is not intended to limit the scope of this term. Color temperature essentially refers to a particular color content or shade (e.g., reddish, bluish) of white light. The color temperature of a given radiation sample conventionally is characterized according to the temperature in degrees Kelvin (K) of a black body radiator that radiates essentially the same spectrum as the radiation sample in question. The color temperature of white light generally falls within a range of from approximately 700 degrees K (generally considered the first visible to the human eye) to over 10,000 degrees K.  
      Lower color temperatures generally indicate white light having a more significant red component or a “warmer feel,” while higher color temperatures generally indicate white light having a more significant blue component or a “cooler feel.” By way of example, a wood burning fire has a color temperature of approximately 1,800 degrees K, a conventional incandescent bulb has a color temperature of approximately 2848 degrees K, early morning daylight has a color temperature of approximately 3,000 degrees K, and overcast midday skies have a color temperature of approximately 10,000 degrees K. A color image viewed under white light having a color temperature of approximately 3,000 degree K has a relatively reddish tone, whereas the same color image viewed under white light having a color temperature of approximately 10,000 degrees K has a relatively bluish tone.  
      Illuminators may be selected so as to produce a desired level of output, such as a desired total number of lumens of output, such as to make a lighting unit  102  consistent with or comparable to another lighting unit  102 , which might be a semiconductor illuminator or might be another type of lighting unit, such as an incandescent, fluorescent, halogen or other light source, such as if a designer or architect wishes to fit semiconductor-based lighting units  102  into installations that use such traditional units.  
      The number and type of semiconductor illuminators can be selected to produce the desired lumens of output, such as by selecting some number of one-watt, five-watt, power package or other LEDs. In embodiments two or three LEDs are chosen. In other embodiments any number of LEDs, such as six, nine, twenty, thirty, fifty, one hundred, three hundred or more LEDs can be chosen.  
      Referring to  FIG. 4 , a system  100  can include a secondary optical facility  400  to optically process the radiation generated by the light sources  300 , such as to change one or both of a spatial distribution and a propagation direction of the generated radiation. In particular, one or more optical facilities may be configured to change a diffusion angle of the generated radiation. One or more optical facilities  400  may be particularly configured to variably change one or both of a spatial distribution and a propagation direction of the generated radiation (e.g., in response to some electrical and/or mechanical stimulus). An actuator  404 , such as under control of a control facility  3500 , can control an optical facility  400  to produce different optical effects.  
      Referring to  FIG. 5 , an optical facility  400  may be a diffuser  502 . A diffuser may absorb and scatter light from a source  300 , such as to produce a glowing effect in the diffuser. As seen in  FIG. 5 , diffusers  502  can take many different shapes, such as tubes, cylinders, spheres, pyramids, cubes, tiles, panels, screens, doughnut shapes, V-shapes, T-shapes, U-shapes, junctions, connectors, linear shapes, curves, circles, squares, rectangles, geometric solids, irregular shapes, shapes that resemble objects found in nature, and any other shape. Diffusers may be made of plastics, polymers, hydrocarbons, coated materials, glass materials, crystals, micro-lens arrays, fiber optics, or a wide range of other materials. Diffusers  502  can scatter light to provide more diffuse illumination of other objects, such as walls or alcoves. Diffusers  502  can also produce a glowing effect when viewed directly by a viewer. In embodiments, it may be desirable to deliver light evenly to the interior surface of a diffuser  502 . For example, a reflector  600  may be disposed under a diffuser  502  to reflect light to the interior surface of the diffuser  502  to provide even illumination.  
      Diffusing material can be a substantially light-transmissive material, such as a fluid, gel, polymer, gas, liquid, vapor, solid, crystal, fiber optic material, or other material. In embodiments the material may be a flexible material, so that the diffuser may be made flexible. The diffuser may be made of a flexible material or a rigid material, such as a plastic, rubber, a crystal, PVC, glass, a polymer, a metal, an alloy or other material.  
      Referring to  FIG. 6 , an optical facility  400  may include a reflector  600  for reflecting light from a light source  300 . Embodiments include a paraboloic reflector  612  for reflecting light from many angles onto an object, such as an object to be viewed in a machine vision system. Other reflectors  600  include mirrors, spinning mirrors  614 , reflective lenses, and the like. In some cases, the optical facility  400  may operate under control of a processor  3600 . Optical facilities  500  can also include lenses  402 , including microlens arrays that can be disposed on a flexible material.  
      Other examples of optical facilities  400  include, but are not limited to, reflectors, lenses, reflective materials, refractive materials, translucent materials, filters, mirrors, spinning mirrors, dielectric mirrors, Bragg cells, MEMs, acousto-optic modulators, crystals, gratings and fiber optics. The optical facility  400  also may include a phosphorescent material, luminescent material, or other material capable of responding to or interacting with the generated radiation.  
      Variable optics can provide discrete or continuous adjustment of beam spread or angle or simply the profile of the light beam emitted from a fixture. Properties can include, but are not limited to, adjusting the profile for surfaces that vary in distance from the fixture, such as wall washing fixtures. In various embodiments, the variable nature of the optic can be manually adjusted, adjusted by motion control or automatically be controlled dynamically.  
      Referring to  FIG. 7 , actuation of variable optics can be through any kind of actuator, such as an electric motor, piezoelectric device, thermal actuator, motor, gyro, servo, lever, gear, gear system, screw drive, drive mechanism, flywheel, wheel, or one of many well-known techniques for motion control. Manual control can be through an adjustment mechanism that varies the relative geometry of lens, diffusion materials, reflecting surfaces or refracting elements. The adjustment mechanism may use a sliding element, a lever, screws, or other simple mechanical devices or combinations of simple mechanical devices. A manual adjustment or motion control adjustment may allow the flexing of optical surfaces to bend and shape the light passed through the system or reflected or refracted by the optical system.  
      Actuation can also be through an electromagnetic motor or one of many actuation materials and devices. Optical facilities  400  can also include other actuators, such as piezo-electric devices, MEMS devices, thermal actuators, processors, and many other forms of actuators.  
      A wide range of optical facilities  400  can be used to control light. Such devices as Bragg cells or holographic films can be used as optical facilities  400  to vary the output of a fixture. A Bragg cell or acoustic-optic modulator can provide for the movement of light with no other moving mechanisms. The combination of controlling the color (hue, saturation and value) as well as the form of the light beam brings a tremendous amount of operative control to a light source. The use of polarizing films can be used to reduce glare and allow the illumination and viewing of objects that present specular surfaces, which typically are difficult to view. Moving lenses and shaped non-imaging surfaces can provide optical paths to guide and shape light.  
      In other embodiments, fluid-filled surfaces  428  and shapes can be manipulated to provide an optical path. In combination with lighting units, such shapes can provide varying optical properties across the surface and volume of the fluid-filled material. The fluid-filled material can also provide a thermal dissipation mechanism for the light-emitting elements. The fluid can be water, polymers, silicone or other transparent or translucent liquid or a gas of any type and mixture with desirable optical or thermal properties.  
      In other embodiments, gelled, filled shapes can be used in conjunction with light sources to evenly illuminate said shapes. Light propagation and diffusion is accomplished through the scattering of light through the shape.  
      In other embodiments, spinning mirror systems such as those used in laser optics for scanning (E.g. bar code scanners or 3D terrain scanners) can be used to direct and move a beam of light. That combined with the ability to rapidly turn on and off a lighting unit  102  can allow a beam of light to be spread across a larger area and change colors to ‘draw’ shapes of varying patterns. Other optical facilities  400  for deflecting and changing light patterns are known and described in the literature: They include methods for beam steering, such as mechanical mirrors, driven by stepper or galvanometer motors and more complex robotic mechanisms for producing sophisticated temporal effects or static control of both color (HS&amp;V) and intensity. Optical facilities  400  also include acousto-optic modulators that use sound waves generated via piezoelectrics to control and steer a light beam. They also include digital mirror devices and digital light processors, such as available from Texas Instruments. They also include grating light valve technology (GLV), as well as inorganic digital light deflection. They also include dielectric mirrors, such as developed at Massachusetts Institute of Technology.  
      Control of form and texture of the light can include not only control of the shape of the beam but also control of the way in which the light is patterned across its beam. An example of a use of this technology may be in visual merchandising, where product ‘spotlights’ could be created while other media is playing in a coordinated manner. Voice-overs or music-overs or even video can be played during the point at which a product is highlighted during a presentation. Lights that move and ‘dance’ can be used in combination with A/V sources for visual merchandising purposes.  
      Optical facilities  400  can be light pipes, lenses, light guides and fibers and any other light transmitting materials.  
      In other embodiments, non-imaging optics are used as an optical facility. Non-imaging optics do not require traditional lenses. They use shaped surfaces to diffuse and direct light. A fundamental issue with fixtures using discrete light sources is mixing the light to reduce or eliminate color shadows and to produce uniform and homogenous light output. Part of the issue is the use of high efficiency surfaces that do not absorb light but bounce and reflect the light in a desired direction or manner. Optical facilities can be used to direct light to create optical forms of illumination from lighting units  102 .  
      The actuator  404  can be any type of actuator for providing linear movement, such as an electromechanical element, a screw drive mechanism (such as used in computer printers), a screw drive, or other element for linear movement known to those of ordinary skill in the art.  
      In embodiments the optical facility is a fluid filled lens, which contains a compressible fluid, such as a gas or liquid. The actuator includes a valve for delivering fluid to the interior chamber of the lens.  
      In embodiments a digital mirror  408  serves as an optical facility  400 . The digital mirror is optionally under control of a processor  3600 , which governs the reflective properties of the digital mirror.  
      In embodiments a spinning mirror system  614  serves as an optical facility  400 . As in other embodiments, the spinning mirror system is responsive to the control of a processor, which may be integrated with it or separate.  
      In embodiments a grating light valve (GLV)  418  serves as an optical facility  400 . The grating light valve can receive light from a lighting unit under control of a processor. GLV uses micro-electromechanical systems (MEMS) technology and optical physics to vary how light is reflected from each of multiple ribbon-like structures that represent a particular “image point” or pixel. The ribbons can move a tiny distance, such as between an initial state and a depressed state. When the ribbons move, they change the wavelength of reflected light. Grayscale tones can also be achieved by varying the speed at which given pixels are switched on and off. The resulting image can be projected in a wide variety of environments, such as a large arena with a bright light source or on a small device using low power light sources. In the GLV, picture elements (pixels) are formed on the surface of a silicon chip and become the source for projection.  
      In embodiments an acousto-optical modulator serves as an optical facility  400 . Also known as a tunable filter and as a Bragg cell, the acousto-optical modulator consists of a crystal that is designed to receive acoustic waves generated, for example, by a transducer, such as a piezoelectric transducer. The acoustic standing waves produce index of refraction changes in the crystal, essentially due to a Doppler shift, so that the crystal serves as a tunable diffraction grating. Incident light, such as from a lighting unit  102 , is reflected in the crystal by varying degrees, depending on the wavelength of the acoustic standing waves induced by the transducer. The transducer can be responsive to a processor, such as to convert a signal of any type into an acoustic signal that is sent through the crystal.  
      Referring again to  FIG. 6 , in embodiments the optical facility  400  is a reflector  612 , such as a reflective dome for providing illumination from a wide variety of beam angles, rather than from one or a small number of beam angles. Providing many beam angles reduces harsh reflections and provides a smoother view of an object. A reflective surface is provided for reflecting light from a lighting unit  102  to the object. The reflective surface is substantially parabolic, so that light from the lighting unit  102  is reflected substantially to the object, regardless of the angle at which it hits the reflective surface from the lighting unit  102 . The surface could be treated to a mirror surface, or to a matte Lambertian surface that reflects light substantially equally in all directions. As a result, the object is lit from many different angles, making it visible without harsh reflections. The object may optionally be viewed by a camera, which may optionally be part of or in operative connection with a vision system. The camera may view the object through a space in the reflective surface, such as located along an axis of viewing from above the object. The object may rest on a platform, which may be a moving platform. The platform, light system  100 , vision system and camera may each be under control of a processor, so that the viewing of the object and the illumination of the object may be coordinated, such as to view the object under different colors of illumination.  
      Referring to  FIG. 7 , optical facilities include a light pipe  420  that reflects light to produce a particular pattern of light at the output end. A different shape of light pipe produces a different pattern. In general, such secondary optics, whether imaging or non-imaging, and made of plastic, glass, mirrors or other materials, can be added to a lighting unit  102  to shape and form the light emission. Such an optical facility  400  can be used to spread, narrow, diffuse, diffract, refract or reflect the light in order that a different output property of the light is created. These can be fixed or variable. Examples can be light pipes, lenses, light guides and fibers and any other light transmitting materials, or a combination of any of these.  
      In embodiments the light pipe  420  serves as an optical facility, delivering light from one or more lighting systems  102  to an illuminated material. The lighting systems  100  are optionally controlled by a control facility  3500 , which controls the lighting systems  102  to send light of selected colors, color temperatures, intensities and the like into the interior of the light pipe. In other embodiments a central controller is not required, such as in embodiments where the lighting systems  102  include their own processor. In embodiments one or more lighting systems  102  may be equipped with a communications facility, such as a data port, receiver, transmitter, or the like. Such lighting systems  102  may receive and transmit data, such as to and from other lighting systems  100 . Thus, a chain of lighting systems  100  in a light pipe may transmit not only light, but also data along the pipe, including data that sends control signals for the lighting systems disposed in the pipe.  
      The optical facility may be a color mixing system  422  for mixing color from a lighting unit  102 . The color mixing system may consist of two opposing truncated conical sections, which meet at a boundary. Light from a lighting unit  102  is delivered into the color mixing system and reflected from the interior surfaces of the two sections. The reflections mix the light and produce a mixed light from the distal end of the color mixing system. U.S. Pat. No. 2,686,866 to Williams, incorporated by reference herein, shows a color mixing lighting apparatus utilizing two inverted cones to reflect and mix the light from multiple sources. By combining a color mixing system such as this with color changes from the lighting unit  102 , a user can produce a wide variety of lighting effects.  
      Other color mixing systems can work well in conjunction with color changing lighting systems  102 . For example, U.S. Pat. No. 2,673,923 to Williams, also incorporated by reference herein, uses a series of lens plates for color mixing.  
      In embodiments an optical facility is depicted consisting of a plurality of cylindrical lens elements. These cylindrical elements diffract light from a lighting unit  102 , producing a variety of patterns of different colors, based on the light from the lighting unit  102 . The cylinders may be of a wide variety of sizes, ranging from microlens materials to conventional lenses.  
      In embodiments the optical facility  400  is a microlens array  424 . The microlens array consists of a plurality of microscopic hexagonal lenses, aligned in a honeycomb configuration. Microlenses are optionally either refractive or diffractive, and can be as small as a few microns in diameter. Microlens arrays can be made using standard materials such as fused silica and silicon and newer materials such as Gallium Phosphide, making possible a very wide variety of lenses. Microlenses can be made on one side of a material or with lenses on both sides of a substrate aligned to within as little as one micron. Surface roughness values of 20 to 80 angstroms RMS are typical, and the addition of various coatings can produce optics with very high transmission rates. The microlens array can refract or diffract light from a lighting unit  102  to produce a variety of effects.  
      In embodiments a microlens array optical facility  400  can consist of a plurality of substantially circular lens elements. The array can be constructed of conventional materials such as silica, with lens diameters on the range of a few microns. The array can operate on light from a lighting unit  102  to produce a variety of colors and optical effects.  
      In embodiments a microlens array is disposed in a flexible material, so that the optical facility  400  can be configured by bending and shaping the material that includes the array.  
      In embodiments a flexible microlens array is rolled to form a cylindrical shape for receiving light from a lighting unit  102 . The configuration could be used, for example, as a light-transmissive lamp shade with a unique appearance.  
      In embodiments a system can be provided to roll a microlens array about an axis. A drive mechanism can roll or unroll the flexible array under control of a controller. The controller can also control a lighting unit  102 , so that the array is disposed in front of the lighting unit  102  or rolled away from it, as selected by the user.  
      The terms “lighting unit,” “luminaire” and “lighting fixture” are used herein to refer to an apparatus including one or more light sources  300 . A given lighting unit  102  may have any one of a variety of mounting arrangements for the light source(s) in a variety of housings  800 . Housings  800  may include enclosures, platforms, boards, mountings, and many other form factors, including forms designed for other purposes. Housings  800  may be made of any material, such as metals, alloys, plastics, polymers, and many others.  
      Referring to  FIG. 8 , housings  800  may include panels  804  that consist of a support platform on which light sources  300  are disposed in an array. Equipped with a diffuser  502 , a panel  804  can form a light tile  802 . The diffuser  502  for a light tile  802  can take many forms, as depicted in  FIG. 8 . The light tile  802  can be of any shape, such as square, rectangular, triangular, circular or irregular. The light tile  802  can be used on or as a part of a wall, door, window, ceiling, floor, or other architectural features, or as a work of art, or as a toy, novelty item, or item for entertainment, among other uses. Housings  800  may be configured as tiles or panels, such as for wall-hangings, walls, ceiling tiles, or floor tiles.  
      Referring to  FIG. 9 , housings  800  may include a housing for an architectural lighting fixture  810 , such as a wall-washing fixture. Housings  800  may be square, rectangular  810 , circular, cylindrical  812 , or linear  814 . A linear housing  814  may be equipped with a diffuser  502  to simulate a neon light of various shapes, or it may be provided without a diffuser, such as to light an alcove or similar location. A housing  800  may be provided with a watertight seal, to provide an underwater lighting system  818 .  
      Housings  800  may be configured to resemble retrofit bulbs, fluorescent bulbs, incandescent bulbs, halogen lamps, high-intensity discharge lamps, or other kinds of bulbs and lamps. Housings  800  may be configured to resemble neon lights, such as for signs, logos, or decorative purposes. Housings  800  may be configured to highlight architectural features, such as lines of a building, room or architectural feature. Housings  800  may be configured for various industrial applications, such as medical lighting, surgical lighting, automotive lighting, under-car lighting, machine vision lighting, photographic lighting, lighting for building interiors or exteriors, lighting for transportation facilities, lighting for pools, spas, fountains and baths, and many other kinds of lighting.  
      Additionally, one or more lighting units similar to that described in connection with  FIG. 2  may be implemented in a variety of products including, but not limited to, various forms of light modules or bulbs having various shapes and electrical/mechanical coupling arrangements (including replacement or “retrofit” modules or bulbs adapted for use in conventional sockets or fixtures), as well as a variety of consumer and/or household products (e.g., night lights, toys, games or game components, entertainment components or systems, utensils, appliances, kitchen aids, cleaning products, etc.).  
      Lighting units  102  encompassed herein include lighting units  102  configured to resemble all conventional light bulb types, so that lighting units  102  can be conveniently retrofitted into fixtures, lamps and environments suitable for such environments. Such retrofitting lighting units  102  can be designed, as disclosed above and in the applications incorporated herein by reference, to use conventional sockets of all types, as well as conventional lighting switches, dimmers, and other controls suitable for turning on and off or otherwise controlling conventional light bulbs. Retrofit lighting units  102  encompassed herein include incandescent lamps, such as A15 Med, A19 Med, A21 Med, A21 3C Med, A23 Med, B10 Blunt Tip, B10 Crystal, B10 Candle, F15, GT, C7 Candle C7 DC Bay, C15, CA10, CA8, G16/1/2 Cand, G16-1/2 Med, G25 Med, G30 Med, G40 Med, S6 Cand, S6 DC Bay, S11 Cand, S11 DC Bay, S11 Inter, S11 Med, S14 Med, S19 Med, LINESTRA 2-base, T6 Cand, T7 Cand, T7 DC Bay, T7 Inter, T8 Cand, T8 DC Bay, T8 Inter, T10 Med, T6-1/2 Inter, T6-1/2 DC Bay, R16 Med, ER30 Med, ER40 Med, BR30 Med, BR40 Med, R14 Inter, R14 Med, K19, R20 Med, R30 Med, R40 Med, R40 Med Skrt, R40 Mog, R52 Mog, P25 Med, PS25 3C, PS25 Med, PS30 Med, PS35 Mog, PS52 Mog, PAR38 Med Skrt, PAR38 Med Sid Pr, PAR46 Scrw Trm, PAR46 Mog End Pr, PAR 46 Med Sid Pr, PAR56 Scrw Trm, PAR56 Mog End Pr, PAR 64 Scrw Trm, and PAR64 Ex Mog End Pr. Also, retrofit lighting units  102  include conventional tungsten/halogen lamps, such as BT4, T3, T4 BI-PIN, T4 G9, MR16, MR11, PAR14, PAR16, PAR16 GU10, PAR20, PAR30, PAR30LN, PAR36, PAR38 Medium Skt., PAR38 Medium Side Prong, AR70, AR  111 , PAR56 Mog End Pr, PAR64 Mog End Pr, T4 DC Bayonet, T3, T4 Mini Can, T3, T4 RSC Double End, T10, and MB19. Lighting units  102  can also include retrofit lamps configured to resemble high intensity discharge lamps, such as E17, ET18, ET23.5, E25, BT37, BT56, PAR20, PAR30, PAR38, R40, T RSC base, T Fc2 base, T G12 base, T G8.5 base, T Mogul base, and TBY22d base lamps. Lighting units  102  can also be configured to resemble fluorescent lamps, such as T2 Axial Base, T5 Miniature Bipin, T8 Medium Bipin, T8 Medium Bipin, T12 Medium Bipin, U-shaped t-12, OCTRON T-8 U-shaped, OCTRON T8 Recessed Double Contact, T12 Recessed Double Contact, T14-1/2 Recessed Double Contact, T6 Single Pin, T8 Single Pin, T12 Single Pin, ICETRON, Circline 4-Pin T-19, PENTRON CIRCLINE 4-pin T5, DULUX S, DULUX S/E, DULUX D, DULUX D/E, DULUX T, DULUX T/E, DULUX T/E/IN, DULUX L, DULUX F, DULUX EL Triple, DULUX EL TWIST DULUX EL CLASSIC, DULUX EL BULLET, DULUX EL Low Profile GLOBE, DULUX EL GLOBE, DULUE EL REFLECTOR, and DULUX EL Circline. Lighting units  102  can also include specialty lamps, such as for medical, machine vision, or other industrial or commercial applications, such as airfield/aircraft lamps, audio visual maps, special purpose heat lamps, studio, theatre, TV and video lamps, projector lamps, discharge lamps, marine lamps, aquatic lamps, and photo-optic discharge lamps, such as HBO, HMD, HMI, HMP, HSD, HSR, HTI, LINEX, PLANON, VIP, XBO and XERADEX lamps. Other lamps types can be found in product catalog for lighting manufacturers, such as the Sylvania Lamp and Ballast Product Catalog 2002, from Sylvania Corporation or similar catalogs offered by General Electric and Philips Corporation.  
      In embodiments the lighting system may have a housing configured to resemble a fluorescent or neon light. The housing may be linear, curved, bent, branched, or in a “T” or “V” shape, among other shapes.  
      Housings  800  can take various shapes, such as one that resembles a point source, such as a circle or oval. Such a point source can be located in a conventional lighting fixture, such as lamp or a cylindrical fixture. Lighting units  102  can be configured in substantially linear arrangements, either by positioning point sources in a line, or by disposing light sources substantially in a line on a board located in a substantially linear housing, such as a cylindrical housing. A linear lighting unit can be placed end-to-end with other linear elements or elements of other shapes to produce longer linear lighting systems comprised of multiple lighting units  102  in various shapes. A housing can be curved to form a curvilinear lighting unit. Similarly, junctions can be created with branches, “Ts,” or “Ys” to created a branched lighting unit. A bent lighting unit can include one or more “V” elements. Combinations of various configurations of point source, linear, curvilinear, branched and bent lighting units  102  can be used to create any shape of lighting system, such as one shaped to resemble a letter, number, symbol, logo, object, structure, or the like.  
      Housings  800  can include or be combined to produce three-dimensional configurations, such as made from a plurality of lighting units  102 . Linear lighting units  102  can be used to create three-dimensional structures and objects, or to outline existing structures and objects when disposed along the lines of such structures and objects. Many different displays, objects, structures, and works of art can be created using linear lighting units as a medium. Examples include pyramid configurations, building outlines and two-dimensional arrays. Linear units in two-dimensional arrays can be controlled to act as pixels in a lighting show.  
      In embodiments the housing  800  may be a housing for an architectural, theatrical, or entertainment lighting fixture, luminaire, lamp, system or other product. The housing  800  may be made of a metal, a plastic, a polymer, a ceramic material, glass, an alloy or another suitable material. The housing  800  may be cylindrical, hemispherical, rectangular, square, or another suitable shape. The size of the housing may range from very small to large diameters, depending on the nature of the lighting application. The housing  800  may be configured to resemble a conventional architectural lighting fixture, such as to facilitate installation in proximity to other fixtures, including those that use traditional lighting technologies such as incandescent, fluorescent, halogen, or the like. The housing  800  may be configured to resemble a lamp. The housing  800  may be configured as a spot light, a down light, an up light, a cove light, an alcove light, a sconce, a border light, a wall-washing fixture, an alcove light, an area light, a desk lamp, a chandelier, a ceiling fan light, a marker light, a theatrical light, a moving-head light, a pathway light, a cove light, a recessed light, a track light, a wall fixture, a ceiling fixture, a floor fixture, a circular fixture, a spherical fixture, a square fixture, a rectangular fixture, an accent light, a pendant, a parabolic fixture, a strip light, a soffit light, a valence light, a floodlight, an indirect lighting fixture, a direct lighting fixture, a flood light, a cable light, a swag light, a picture light, a portable luminaire, an island light, a torchiere, a boundary light, a flushor any other kind architectural or theatrical lighting fixture or luminaire.  
      Housings may also take appropriate shapes for various specialized, industrial, commercial or high performance lighting applications. For example, in an embodiment a miniature system, such as might be suitable for medical or surgical applications or other applications demanding very small light systems  100 , can include a substantially flat light shape, such as round, square, triangular or rectangular shapes, as well as non-symmetric shapes such as tapered shapes. In many such embodiments, housing  800  could be generally described as a planar shape with some small amount of depth for components. The housing  800  can be small and round, such as about ten millimeters in diameter (and can be designed with the same or similar configuration at many different scales.) The housing  800  may include a power facility, a mounting facility and an optical facility. The housing  800  and optical facility can be made of metals or plastic materials suitable for medical use.  
      Referring to  FIG. 10 , a housing  800  for a lighting unit  100  may serve as a housing for another object as well, such as a compact  1002 , a flashlight  1004 , a ball  1008 , a mirror  1012 , an overhead light  1014 , a wand  1010 , a traffic light  1020 , a mirror  1018 , a sign  1022 , a toothbrush  1024 , a cube  1028  (such as a Lucite cube), a display  1030 , a handheld computer  1032 , a phone  1034 , or a block  1038 . Almost any object can be integrated with a lighting unit  102  to provide a controlled lighting feature.  
       FIG. 11  shows additional housings  800  for lighting units  102 , such as blocks  1104 , balls  1108 , pucks  1110 , spheres  1112 , and lamps  1114 .  
      Referring to  FIG. 11 , housings  800  may also take the form of a flexible band  1102 , tape or ribbon to allow the user to conform the housing to particular shapes or cavities. Similarly, housings  800  can take the form of a flexible string  1104 . Such a band  1102  or string  1104  can be made in various lengths, widths and thicknesses to suit specific demands of applications that benefit from flexible housings  800 , such as for shaping to fit body parts or cavities for surgical lighting applications, shaping to fit objects, shaping to fit unusual spaces, or the like. In flexible embodiments it may be advantageous to use thin-form batteries, such as polymer or “paper” batteries for small bands  1102  or strings  1104 .  
      Referring to  FIG. 12 , lighting units  102  can be disposed in a sign  1204 , such as to provide lighting. Combined with diffusers  502 , the lighting units  102  can produce an effect similar to neon lights. Signs  1204  can take many different forms, with lighting units  102 , housings  800  and diffusers  502  shaped to resemble logos, characters, numbers, symbols, and other signage elements. In embodiments the sign  1204  can be made of light-transmissive materials. Thus, a sign  1204  can glow with light from the lighting units  102 , similar to the way a neon light glows. The sign  1204  can be configured in letters, symbols, numbers, or other configurations, either by constructing it that way, or by providing sub-elements that are fit together to form the desired configuration. The light from the lighting units  102  can be white light, other colors of light, or light of varying color temperatures. In an embodiment the sign  1204  can be made from a kit that includes various sub-elements, such as curved elements, straight elements, “T” junctions, “V-” and “U-” shaped elements, and the like.  
      In embodiments a housing  800  may be configured as a sphere or ball, so as to produce light in substantially all directions. The ball housing  800  can be made of plastic or glass material that could be transparent for maximum light projection or diffuse to provide softer light output that is less subject to reflections. The ball housing  800  could be very small, such as the size of a marble or a golf ball, so that it is easily managed in environments that require miniature light systems  100 , or it could be very large, such as in art, architectural, and entertainment applications. Multiple balls can be used simultaneously to provide additional light. If it is desired to have directional light from a ball lighting system  100 , then part of the ball can be made dark.  
      Housings  800  can incorporate lighting units  102  into conventional objects, such as tools, utensils, or other objects. For example, a housing  800  may be shaped into a surgical tool, such as tweezers, forceps, retractors, knives, scalpels, suction tubes, clamps or the like. A lighting unit  102  can be collocated at the end of a tool and provide illumination to the working area of the tool. One of many advantages of this type of tool is the ability to directly illuminate the working area, avoiding the tendency of tools or the hands that use them to obscure the working area. Tools can have onboard batteries or include other power facilities as described herein.  
      Housings  800  can also be configured as conventional tools with integrated lighting units  102 , such as hammers, screw drivers, wrenches (monkey wrenches, socket wrenches and the like), pliers, vise-grips, awls, knives, forks, spoons, wedges, drills, drill bits, saws (circular saws, jigsaws, mitre saws and the like), sledge hammers, shovels, digging tools, plumbing tools, trowels, rakes, axes, hatchets and other tools. As with surgical tools, including the lighting unit  102  as part of the tool itself allows lighting a work area or work piece without the light being obscured by the tool or the user.  
      Referring to  FIG. 13 , a housing may be configured to resemble a conventional MR-type halogen fixture  1300 . A rectangular opening  1302  in the housing  800  allows the positioning of a connector that serves as an interface  4904  between a socket into which the housing  800  is positioned and a board  204  that bears the light sources  300 , which include a plurality of LEDs. The interface  4904  provides a mechanical, electrical and data connection between the board  204  and the socket into which the housing  800  is placed. In embodiments the fixture  1300  is made of a heat-conducting material, such as metal. The housing  800  may be cast as a single unit or cast in separate halves. In embodiments an additional heat shield  1304  may shield the LEDs from heat that may come from the power/data circuitry. In embodiments a metal mesh may exist between the light sources  300  and the lens  1308 . The lens  1308  may be attached by a screw-type cap  1308  with a central space for allowing light to shine from the fixture  1302 . In embodiments a side of the lens  1308  may be coated to prevent reflection of radiation back to the light sources  300  to reduce heat in the environment of the light sources  300 . The lens  1308  may protect the light sources  300  and electronic components located on the board  204  from damage and prevent a user from touching the electronic components, which could result in electric shock. In embodiments the light sources  300  may be heat-resistant LEDs. The board  204  may be a metal core board for accepting heat from the light sources  300  and trapping the heat away from the light sources  300 . The interior of the unit  1300  may be filled with a potting facility for trapping heat away from the light sources  300 . The board  204  may be a printed circuit board. In embodiments the housing  800  may include a thermally conductive material, such as a potting material or an adhesive. In embodiments a power/data supply may be on board the fixture  1302 .  
      Referring to  FIGS. 14   a  and  14   b , a housing  800  may be a linear housing  1402 . Referring to  FIG. 14   a , the housing may include connectors  1404  located at the ends of the linear housing  1402 , so that separate modular units of the housing  1402  can be connected end-to-end at a junction  1412  with little spacing in between. The connectors  1404  of  FIG. 14   b  extend from the housing  800 . The connectors  1404  can be designed to transmit power and data from one lighting unit  102  to another lighting unit  102  having a similar linear housing  1402 . The power and data may be fed through the interior of the lighting unit  1402 . The top of the housing can include a slot  1408  into which light sources  300  are disposed. The light sources  300  may be high-brightness LEDs. The housing  800  can be fit with a lens  1412  for protecting the light sources  300  or shaping light coming from the light sources  300 . The lens  1412  can be provided with a very tight seal, such as to prevent a user from touching the light sources  300  or any of the drive circuitry. In embodiments the housing  1402  may house drive circuitry for a high-voltage embodiment, as described in more detail below and in applications incorporated herein by reference. In embodiments the housing  1402  may include a cover  1414  for covering the connector  1404  if the connector is not in use. The linear housing  1402  can be deployed to produce many different effects in many different environments, as described in connection with other linear embodiments described herein. In one preferred embodiment, lighting units  102  with linear housings  1402  are strung end-to-end in an alcove to light the alcove. In another preferred embodiments, such lighting units  102  with linear housings  1402  are connected end-to-end across the base of a wall or other architectural feature to wash the wall or other feature with light of varying colors.  
      Referring to  FIG. 14   c , a cut-through view of the housing  1402  is depicted, showing the lens  1412 , circuit board  204 , light sources  300  and other elements. An element  1418  can be used to hold down the lens  1412 . Fasteners  1424  attach the top part of the housing  1402  to the bottom part of the housing  1402 . Lines  1420 ,  1422  for power and data run through the housing  1402 . In embodiments a metal plate  1428  conducts heat away from the board  204  and the light sources  300 . In embodiments the interior space  1430  may be filled with potting material to trap heat away from the light sources  300 . Gaskets  1432  can connect the inner part of the housing  1402  to the outer part. The housing  1402  may include substantial heat-conducting mass, to trap heat away from the light sources  300 . The housing  1402  may include a board  1434  with a power facility, such as a power-on-board power facility. Cooling fins  1438  may provide additional cooling for the housing  1402 .  
       FIG. 14   d  shows a side cut view of the housing  1402 . The board  204  with the light sources  300  is disposed in the housing  1402 . The power-on-board power facility  1434  is disposed in the housing  1402 . A power bus  1440  carries power to the power-on-board power facility  1434 .  
      In embodiments a light source  300  may be equipped with a primary optical facility  1700 , such as a lens, diode package, or phosphor for shaping, spreading or otherwise optically operating on photons that exit the semiconductor in an LED. For example, a phosphor may be used to convert UV or blue radiation coming out of a light source  300  into broader band illumination, such as white illumination. Primary optical facilities may include packages such as those used for one-watt, three-watt, five-watt and power packages offered by manufacturers such as LumiLeds, Nichia, Cree and Osram-Opto.  
      In one embodiment, the lighting unit  102  or a light source  300  of  FIGS. 1 and 2  may include and/or be coupled to a power facility  1800 . In various aspects, examples of power facilities  1800  include, but are not limited to, AC power sources, DC power sources, batteries, solar-based power sources, thermoelectric or mechanical-based power sources and the like. Additionally, in one aspect, the power facility  1800  may include or be associated with one or more power conversion devices that convert power received by an external power source to a form suitable for operation of the lighting unit  102 .  
      Light sources  300  have varying power requirements. Accordingly, lighting units  102  may be provided with dedicated power supplies that take power from power lines and convert it to power suitable for running a lighting unit  102 . Power supplies may be separate from lighting units  102  or may be incorporated on-board the lighting units  102  in power-on-board configurations. Power supplies may power multiple lighting units  102  or a single lighting unit  102 . In embodiments power supplies may provide low-voltage output or high-voltage output. Power supplies may take line voltage or may take power input that is interrupted or modified by other devices, such as user interfaces  4908 , such as switches, dials, sliders, dimmers, and the like.  
      In embodiments a line voltage power supply is integrated into a lighting system  100  and a power line carrier (PLC) serves as a power facility  1800  and as a control facility  3500  for delivering data to the lighting units  102  in the lighting system  100  over the power line. In other cases a lighting system  100  ties into existing power systems (120 or 220 VAC), and the data is separately wired or provided through wireless.  
      A power facility  1800  may include a battery, such as a watch-style battery, such as Lithium, Alkaline, Silver-Zinc, Nickel-Cadmium, Nickel metal hydride, Lithium ion and others. The power facility  1800  may include a thin-form polymer battery that has the advantage of being very low profile and flexible, which can be useful for lighting unit configurations in flexible forms such as ribbons and tape. A power facility  1800  may also comprise a fuel cell, photovoltaic cell, solar cell or similar energy-producing facility. A power facility  1800  may be a supercapacitor, a large-value capacitor that can store much more energy than a conventional capacitor. Charging can be accomplished externally through electrical contacts and the lighting device can be reused. A power facility  1800  can include an inductive charging facility. An inductive charging surface can be brought in proximity to a lighting unit  102  to charge an onboard power source, allowing, for example, a housing  800  to be sealed to keep out moisture and contaminants.  
      Battery technologies typically generate power at specific voltage levels such as 1.2 or 1.5V DC. LED light sources  300 , however, typically require forward voltages ranging from around 2 VDC to 3.2 VDC. As a result batteries may be put in series to achieve the required voltage, or a boost converter may be used to raise the voltage.  
      It is also possible to use natural energy sources as a power facility  1800 , such as solar power, the body&#39;s own heat, mechanical power generation, the body&#39;s electrical field, wind power, water power, or the like.  
      Referring to  FIG. 15 , in embodiments it is desirable to supply power factor correction (PFC) to power for a lighting unit  102 . In a power-factor-corrected lighting system  102 , a line interference filter and rectifier  1802  may be used to remove interference from the incoming line power and to rectify the power. The rectified power can be delivered to a power factor corrector  1804  that operates under control of a control circuit  1810  to provide power factor correction, which is in turn used to provide a high voltage direct current output  1808  to the lighting unit  102 . Many embodiments of power factor correction systems can be used as alternatives to the embodiment of  FIG. 15 .  
       FIG. 16   a  shows an embodiment of a lighting system  100  with a power factor correction facility  1804 . The line filter and rectifier  1802  takes power from the line, filters and rectifies the power, and supplies it to the power factor correction facility  1804 . The embodiment of  FIG. 16   a  includes a DC to DC converter  1812  that converts the output of the power factor correction facility  1804  to, for example, twenty-four volt power for delivery via a bus. The bus also carries data from a data converter  1904 , which carries a control signal for the lighting units  102  that are attached to the bus that carries both the power and the data. In the embodiment of  FIG. 16   b , the DC to DC converter  1812  is disposed locally at each lighting unit  102 , rather than in a central power supply as in  FIG. 16   a.    
       FIG. 17  shows an embodiment where the power factor correction facility  1804  and DC to DC converter  1812  are integrated into a single stage power factor correction/DC to DC converter facility  1908  that is integrated with the lighting unit  102 , rather than being contained in a separate power supply. The alternating current line power is delivered to a high-voltage three wire power/data bus  1910  that also carries input from a data converter  1904  that carries control signals for the lighting unit  102 . Power factor correction and conversion to DC output voltages suitable for light sources  300  such as LEDs occurs at the lighting units  102 . Unlike conventional power supplies where power factor correction is absent or present only in a separate power supply, the local power factor correction/DC to DC converter  1908  can take line voltage and correct it to an appropriate input for a LED light source  300  even if the line voltage has degraded substantially after a long run of wire. The configuration of  FIG. 17  and other alternative embodiments that supply power factor correction and voltage conversion on board allow lighting units  102  to be configured in long strings over very large geometries, without the need to install separate power supplies for each lighting unit  102 . Accordingly, it is one preferred embodiment of a power supply for disposing lighting units  102  on building exteriors and other large environments where it is inconvenient to install or maintain many separate power supplies.  
      In embodiments it is desirable to provide power and data over the same line. Referring to  FIG. 18 , a multiplexer  1850  takes a data input and a direct current power input and combines them to provide a combined power and data signal.  1852 .  
      Semiconductor devices like LED light sources  300  can be damaged by heat; accordingly, a system  100  may include a thermal facility  2500  for removing heat from a lighting unit  102 . Referring to  FIG. 19 , the thermal facility  2500  may be any facility for managing the flow of heat, such as a convection facility  2700 , such as a fan  2702  or similar mechanism for providing air flow to the lighting unit  102 , a pump or similar facility for providing flow of a heat-conducting fluid, a vent  2704  for allowing flow of air, or any other kind of convection facility  2700 . A fan  2702  or other convection facility  2700  can be under control of a processor  3600  and a temperature sensor such as a thermostat to provide cooling when necessary and to remain off when not necessary.  
      The thermal facility  2500  can also be a conduction facility  2600 , such as a conducting plate or pad of metal, alloy, or other heat-conducting material, a gap pad  2602  between a board  204  bearing light sources  300  and another facility, a thermal conduction path between heat-producing elements such as light sources  300  and circuit elements, or a thermal potting facility, such as a polymer for coating heat-producing elements to receive and trap heat away from the light sources  300 . The thermal facility  2500  may be a radiation facility  2800  for allowing heat to radiate away from a lighting unit  102 . A fluid thermal facility  2900  can permit flow of a liquid or gas to carry heat away from a lighting unit  102 . The fluid may be water, a chlorofluorocarbon, a coolant, or the like. In a preferred embodiment a conductive plate is aluminum or copper. In embodiments a thermal conduction path  2720  conducts heat from a circuit board  204  bearing light sources  300  to a housing  800 , so that the housing  800  radiates heat away from the lighting unit  102 .  
      Referring to  FIG. 20 , a mechanical interface  3200  may be provided for connecting a lighting unit  102  or light source  300  mechanically to a platform, housing  800 , mounting, board, other lighting unit  102 , or other product or system. In embodiments the mechanical interface  3200  may be a modular interface for removeably and replaceably connecting a lighting unit  102  to another lighting unit  102  or to a board  204 . A board  204  may include a lighting unit  102 , or it may include a power facility for a lighting unit  102 .  
      In embodiments the modular interface  3202  comprises a board  204  with a light source  300  on one side and drive circuit elements on the other side, or two boards  204  with the respective elements on opposites sides and the boards  204  coupled together. The modular interface  3202  may be designed to allow removal or replacement of a lighting unit  102 , either in the user environment of the lighting unit  102  or at the factory. In embodiments a lighting unit  102  has a mechanical retrofit interface  3300  for allowing it to fit the housing of a traditional lighting source, such as a halogen bulb  3302 . In embodiments the modular interface  3200  is designed to allow multiple lighting units  102  to fit together, such as a modular block  3204  with teeth, slots, and other connectors that allow lighting units  102  to serve as building blocks for larger systems of lighting units  102 .  
      In embodiments the retrofit interface  3300  allows the lighting unit  102  to retrofit into the mechanical structure of a traditional lighting source, such as screw for an Edison-mount socket, pins for a Halogen socket, ballasts for a fluorescent fixture, or the like.  
      In embodiments the mechanical interface is a socket interface  3400 , such as to allow the lighting unit  102  to fit into any conventional type of socket, which in embodiments may be a socket equipped with a control facility  3500 , i.e., a smart socket.  
      In embodiments the mechanical interface  3200  is a circuit board  204  on which a plurality of light sources  300  are disposed. The board  204  can be configured to fit into a particular type of housing  800 , such as any of the housings  800  described above. In embodiments the board  204  may be moveably positioned relative to the position of the housing  800 . A control facility may adjust the position of the board  204 .  
      A kit may be provided for producing an illumination system, which may include light sources  300 , components for a control facility  3500 , and instructions for using the control facility components to control the light sources  300  to produce an illumination effect.  
      In embodiments a control facility  3500  for a light source  300  may be disposed on a second board  204 , so that the control facility  3500  can be moveably positioned relative to the board  204  on which the light sources  300  are disposed. In embodiments the board for the control facility  3500  and the board  204  for the light sources  300  are configured to mechanically connect in a modular way, permitting removal and replacement of one board  204  relative to the other, whether during manufacturing or in the field.  
      A developer&#39;s kit may be provided including light sources  300 , a circuit board  204  and instructions for integrating the board  204  into a housing  800 . A board  204  with light sources  300  may be provided as a component for a manufacturer of a lighting system  100 . The component may further include a chip, firmware, and instructions or specifications for configuring the system into a lighting system  100 .  
      In embodiments a board  204  carrying LEDs may be configured to fit into an architectural lighting fixture housing  800  or other housing  800  as described above.  
      In embodiments, a light source  300  can be configured with an off-axis mounting facility or a light shade that selectively allows light to shine through in certain areas and not in others. These techniques can be used to reduce glare and light shining directly into the eyes of a user of the lighting unit  102 . Snap-on lenses can be used atop the light-emitting portion to allow for a much wider selection of light patterns and optical needs. In embodiments a disk-shaped light source  300  emits light in one off-axis direction. The light can then be rotated about the center axis to direct the light in a desired direction. The device may be simply picked up, rotated, and placed back down using the fastening means such as magnetic or clamp (see below for more fastening options) or may simply incorporate a rotational mechanism.  
      Referring to  FIG. 21 , in embodiments the mechanical interface  3200  may connect light sources  300  to fiber bundles  2102  to create flexible lighting units  102 . A lighting unit  102  can be configured to be incorporated directly in a tool  2104 , so that the fiber transports the light to another part of the tool  2104 . This would allow the light source  300  to be separated from the ‘working’ end of the tool  2104  but still provide the lighting unit  102  without external cabling and with only a short efficient length of fiber. An electro-luminescent panel can be used wherein the power is supplied via onboard power in the form of a battery or a cable or wire to an off board source.  
      A mechanical interface  3200  may include facilities for fastening lighting units  102  or light sources  300 , such as to platforms, tools, housing or the like. Embodiments include a magnetic fastening facility. In embodiments a lighting unit  102  is clamped or screwed into a tool or instrument. For example, a screw-type clamp  2108  can be used to attach a lighting unit  102  to another surface. A toggle-type clamp can be used, such as De-Sta-Co style clamps as used in the surgical field. A clip or snap-on facility can be used to attach a lighting unit  102  and allow flexing elements. A flexible clip  2110  can be added to the back of a lighting device  102  to make it easy to attach to another surface. A spring-clip, similar to a binder clip, can be attached to the back of a lighting unit  102 . A flexing element can provide friction when placed on another surface. Fasteners can include a spring-hinge mechanism, string, wire, Ty-wraps, hook and loop fastener  2114 , adhesives or the like. Fastening materials include bone wax  2112 ; a beeswax compound (sometimes mixed with Vaseline), which can be hand, molded, and can also be used for holding the lighting device  102 . The exterior of the lighting device  102  can be textured to provide grip and holding power to facilitate the fastening. Tapes, such as surgical DuoPlas tape from Sterion, are another example of materials that can be used to fasten the light to tools, instruments, and drapes or directly to the patient.  
      Mechanical interfaces  3200  configured as boards  204  on which light sources  300  are disposed can take many shapes, including shapes that allow the boards  204  to be used as elements, such as tiles, to make up larger structures. Thus, a board  204  can be a triangle  2118 , square  2120 , hexagon, or other element that can serve as a subunit of a larger pattern, such as a two-dimensional planar pattern or a three-dimensional object, such as a regular polyhedron or irregular object.  
      Referring to  FIG. 22   a , boards  204  can provide a mechanical and electrical connection  2202 , such as with matching tabs and spaces that fit into each other to hold the boards  204  together. Such boards can build large structures. For example, a large number of triangular boards  2118  can be arranged together to form a substantially spherical configuration  2204  that resembles a large ball, with individual lighting units  102  distributed about the entire perimeter to shine light in substantially all directions from the ball sphere  2204 .  
      In embodiments, the boards  204  may be used as interlocking, substantially similar, repeated subassemblies whose interlocking mechanism can provide both mechanical strength and electrical connectivity. In embodiments the geometry of interlocking repeated subassemblies enable accurate and precise positioning of light sources  300 . The interlocking assemblies product displays of various physical shapes, and lighting units  100  can be individually addressed and controlled to achieve appearances that differ from varying points of view.  
      When considering the question of how to subdivide the volume of a space into a collection of illuminated areas, it is immediately evident that many of the desired subdivision schemes will have a significant degree of regularity and symmetry. For example, a relatively small, roughly spherical luminaire in a large room would naturally lend itself to being constructed from a set of narrow- to medium-angle light emitters that point radially outward from the center of the sphere. Similarly, a roughly cylindrical luminaire might consist of a set of linear emitters pointing radially outward, or a half-cylinder might consist of a set of linear emitters pointing inward, whose beams cross as they exit the fixture.  
      In any case, for reasons of both manufacturability and simplicity of design, it is desirable to utilize a light source  300  with a specific shape, size and feature set that can be repeated many times throughout the lighting unit  100 . Such a lighting unit  100  might be appreciably planar, so that it could touch other such lighting units  100  edge to edge, or a lighting unit  100  might occupy a certain volume, so that it could touch other such lighting units  100  surface to surface or face to face. This lighting unit  100  could be considered a “tile,” and a number of these units in proximity to each other, touching edge to edge or face to face, would constitute a tessellation. The tessellation need not be regular and need not repeat, and the tiles need not all be identical.  
      In embodiments boards  204  formed into tiles can be assembled into a tessellation. Since edges or faces of the boards  204  or tiles will be in contact with one another, and since the geometric possibilities for the set of interfaces between tiles is strictly limited by the parameters of the tiles, it becomes evident that these points of contact are eminently suited for both the mechanical fastening required to hold the tessellation together and for the electrical connections required to power the light source in each tile. Thus, a properly designed tile will incorporate a fastening scheme such that one tile&#39;s edge can be securely attached to another tile&#39;s edge, and/or such that one tile&#39;s face can be securely attached to another tile&#39;s face. Also, a properly designed tile would incorporate an electrical interconnection mechanism on an edge and/or face such that one tile&#39;s edge or face can provide electrical signals to, or obtain electrical signals from, a mating tile. It should be noted that, geometrically speaking, sets of interconnected units such as has been described here generally obtain very high strength via the distribution of loads and stresses throughout the structure as a whole. As a consequence, properly designed tiles, assembled with each other, may obviate the need for any auxiliary framework, superstructure or backbone to support the structure as a whole. Likewise, the tile-to-tile electrical connections may obviate the need for any auxiliary wiring. The shape and functionality of a lighting unit  100  constructed of these tiles can therefore be an emergent property of the design of the tiles themselves.  
      Furthermore, as a geometric consequence of the tessellation of tiles with specific geometric properties, the absolute position and orientation of each tile in three-dimensional space can be represented mathematically as a function of the tile&#39;s shape; therefore it is equally possible to choose a desired mathematical representation for the geometry of the lighting unit  100  and work in the other direction to search for tile shapes from which that structure can be made.  
      The present invention exploits this property that simple tiles with simple geometry can be assembled into complex structures with complex geometry. By way of example: An icosahedron can be constructed from twenty edge-connected triangles, each with sides measuring exactly one inch. The number one is a rational number, and one inch is easy to measure and fabricate, but when interconnected the vertices of these triangles have irrational coordinates in three-space and tiles&#39; faces meet at edges whose fastening angle is an irrational number. Were one to fabricate an icosahedron from a block of metal, one would have to invest substantial effort to cut all the faces with the desired degree of precision, but were one to construct an icosahedron from twenty identical triangles, very high precision would be obtained with the trivial step of measuring an equilateral triangle. In relation to a luminaire, one therefore is able to position and orient each tile&#39;s light source with high precision and accuracy, simply by ensuring that one particular kind of tile can be reliably, repeatably manufactured and reliably interconnected to its neighbors.  
      Thus far, given examples have related to the use of light sources  300  that are intended to project light from the lighting unit  100  for the purposes of illuminating the surrounding space. But the present invention is equally relevant to the use of light sources that are intended to be viewed directly. A tile could have one or many light sources  300  on it, arranged in some pattern or design, so that when interconnected with other tiles a larger pattern emerges. Rectangular, planar matrix displays consisting of orthogonal rows and columns of pixels are commonplace, but displays with non-orthogonal sets of pixels and, in particular, three-dimensional displays are rare. Again, the emergent pattern may have a degree of complexity and precision that is substantially in excess of the complexity and precision inherent in a single tile.  
      Finally, if a display is three-dimensional, its appearance will vary depending on where a viewer is standing. A roughly spherical display would appear spherical-shaped from any viewpoint, but the pixels on one section of the sphere need not behave the same way as pixels elsewhere on the sphere. Hence, two viewers looking at the same sphere from different angles will see different patterns on the display.  
      Referring to  FIG. 22   b , in embodiments the board  204  may consist of a rectangular board  204 , with an array  2208  of light sources  300 . In the embodiment depicted in  FIG. 22   b , the array is a six-by-six array on a square board  204  with six-inch sides. The array  2208  can have any number of light sources  300  and take on any other dimensions. The light sources may consist of miniature groups of LEDs, such as red, green, blue, white or other colors of LEDs. In embodiments each light source  300  is comprised of a triad of red, green and blue surface mount LEDs. The square array makes it very convenient for the array  2208  to be placed side by side with other boards  204  containing similar arrays  2208 , so that effects can be generated across multiple arrays  2208 , such as an extended system covering a wall or the outside of a building. That is, the arrays  2208  can serve as modular components of larger lighting systems. To facilitate rapid installation, the board  204  may have a plurality of pre-fabricated screw holes  2210  that make it very convenient to attach the board  204  to a wall or other mounting area. In embodiments the board  204  is provided with a protective cover  2212 , such as a plastic cover to protect the board from damage and to prevent a user from touching electrical connections on the board  204 . The cover  2212  may include spaces  2214 , so that a viewer can see the light sources  300  directly without having light diffused through the cover  2212 . In other embodiments the cover  2212  may be a light transmitting cover or a light diffusing cover.  
      Referring to  FIG. 22   c , in another embodiment the array  2208  of light sources  300  may be a three-by-three array, less dense than the six-by-six array of  FIG. 22   b , but including similar elements, such as the board  204  (again a six-inch by six-inch board  204 ), the cover  2212 , the screw holes  2210  and the spaces  2214  through which the viewer can directly see the light sources  300 . Again the light sources  300  may consist of various colors of LED, such as a trio of red, green and blue surface mount LEDs.  
       FIG. 22   d  shows the back of a board  204  such as the rectangular array  2208  boards  204  described in connection with  FIGS. 22   b  and  22   c . The board  204  includes a jack  2218  for taking in power and data from a source and a jack  2220  for sending power and data out. In embodiments the jacks  2218 ,  2220  allow the board  204  to be aligned in series with other boards  204 , where data from a central controller is passed from board-to-board by the jacks  2218 ,  2220 . In embodiments each group of light sources  300  in the array  2208  may be provided with a processor  3600 , such as an ASIC, for handling lighting control signals for the light sources  300 . In embodiments the ASICs  3600  are disposed in series and are controlled by a serial control facility such as described herein, where each ASIC takes a data stream, responds to the first unmodified byte, modifies the byte to which it responds, and sends the modified data stream to the next ASIC. The ASICs  3600  on the back of the board  204  may be strung in an array, such as the six-by-six array  2208  or the three-by-three array  2208 . In embodiments each of the ASICs  3600  is disposed along with a resistor and a capacitor on the back of the board  204 . The board  204  may also contain an additional ASIC  2230 , such as to allow a central controller to identify the particular type of board  204  on which the ASICs are disposed, such as to identify the board  204  as a six-by-six or three-by-three array. The board  204  may also include extrusions  2228  from the screw holes  2210  of the board. The extrusions  2228  guide the screws that attached the board  204  to a surface, and they also provide an offset between the back of the board  204  and the surface, so that the ASICs  3600  or other components are not crushed when the board  204  is attached to the surface. Corner extrusions  2224  provide an offset at the corners of the board  204  as well.  
      In embodiments the cover  2212  may be fitted with lenses, diffusers or other optical facilities  400  that shape the light coming from the light sources  300  that make up the arrays  2208 , such as to increase the viewing angle of light sources  300 .  
      In embodiments the lighting units  100  may include a dipline style mounting panel that allows units to be placed anywhere on a surface. The boards  204  may include integrated hash marks for aligning units  100  during installation. In embodiments boards  204  may have an integrated laser level to facilitate accurate installation. In this embodiment a layered surface of conductors such as Dipline-style (Dipline is a trademarked layered conductive mounting material) surface material is used to allow units to be placed anywhere on surface by inserting of modular attached pin connectors to be pushed through the surface of the materials to make contact with selected conductive layers within the surface.  
       FIG. 14  showed a mechanical interface  3200  for connecting two linear lighting units  102  end-to-end. Another mechanical interface  3200  is seen in  FIG. 23 , where cables  2322  exit a portal  2324  in the housing  800  and enter a similar portal  2324  in the housing  800  of the next linear unit  102 , so that the two units  102  can be placed end-to-end. A protective cover  2320  can cover the cables  2322  between the units  102 . The cables  2322  can carry power and data between the units  102 .  
      In embodiments, mechanical interfaces  3200  can include thermal facilities  2500  such as those described above as well as facilities for delivering power and data.  
      A control facility  3500  may produce a signal for instructing a light system  100  lighting unit  102  to produce a desired light output, such as a mixture of light from different light sources  300 . Control facilities can be local to a lighting unit  102  or remote from the lighting unit  102 . Multiple lighting units  102  can be linked to central control facilities  3500  or can have local control facilities  3500 . Control facilities can use a wide range of data protocols, ranging from simple switches for “on” and “off” capabilities to complex data protocols such as Ethernet and DMX.  
      Referring to  FIG. 24   a , a control facility  3500  may include drive hardware  3800  for delivering controlled current to one or more light sources  300 . Referring to  FIGS. 24   a  and  24   b , control signals from a control facility  3500 , such as a central data source, are used by a processor  3600  that controls the drive hardware  3800 , causing current to be delivered to the light sources  300  in the desired intensities and durations, often in very rapid pulses of current, such as in pulse width modulation or pulse amplitude modulation, or combinations of them, as described below. Two examples of drive hardware  3800  circuits are shown in  FIG. 24 , but many alternative embodiments are possible, including those described in the patent incorporated by reference herein. Referring to  FIG. 24   c  in embodiments power from a power facility  1800  and data from a control facility  3500  are delivered together as an input  2402 . A dipswitch  2408  can be used to provide a processor  3600  with a unique address, so that the lighting unit  102  responds to control signals intended for that particular lighting unit  102 . The processor  3600  reads the power/data input and drives the drive hardware  3800  to provide current to the light sources  300 .  
      In embodiments the control facility  3500  includes the processor  3600 . “Processor” or “controller” describes various apparatus relating to the operation of one or more light sources. A processor or controller can be implemented in numerous ways, such as with dedicated hardware, using one or more microprocessors that are programmed using software (e.g., microcode or firmware) to perform the various functions discussed herein, or as a combination of dedicated hardware to perform some functions and programmed microprocessors and associated circuitry to perform other functions. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers, including by retrieval of stored sequences of instructions.  
      In particular, in a networked lighting system environment, as discussed in greater detail further below (e.g., in connection with  FIG. 2 ), as data is communicated via the network, the processor  3600  of each lighting unit coupled to the network may be configured to be responsive to particular data (e.g., lighting control commands) that pertain to it (e.g., in some cases, as dictated by the respective identifiers of the networked lighting units). Once a given processor identifies particular data intended for it, it may read the data and, for example, change the lighting conditions produced by its light sources according to the received data (e.g., by generating appropriate control signals to the light sources). In one aspect, a data facility  3700  of each lighting unit  102  coupled to the network may be loaded, for example, with a table of lighting control signals that correspond with data the processor  3600  receives. Once the processor  3600  receives data from the network, the processor may consult the table to select the control signals that correspond to the received data, and control the light sources of the lighting unit accordingly.  
      In one aspect of this embodiment, the processor  3600  of a given lighting unit, whether or not coupled to a network, may be configured to interpret lighting instructions/data that are received in a DMX protocol (as discussed, for example, in U.S. Pat. Nos. 6,016,038 and 6,211,626), which is a lighting command protocol conventionally employed in the lighting industry for some programmable lighting applications. However, it should be appreciated that lighting units suitable for purposes of the present invention are not limited in this respect, as lighting units according to various embodiments may be configured to be responsive to other types of communication protocols so as to control their respective light sources.  
      In other embodiments the processor  3600  may be an application specific integrated circuit, such as one configured to respond to instructions according to a protocol, such as the DMX protocol, Ethernet protocols, or serial addressing protocols where each ASIC responds to control instructions directed to it, based on the position of the ASIC in a string of similar ASICs.  
      In various implementations, a processor or controller may be associated with a data facility  3700 , which can comprise one or more storage media (generically referred to herein as “memory,” e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present invention discussed herein.  
      In embodiments the data storage facility  3700  stores information relating to control of a lighting unit  102 . For example, the data storage facility may be memory employed to store one or more lighting programs for execution by the processor  3600  (e.g., to generate one or more control signals for the light sources), as well as various types of data useful for generating variable color radiation (e.g., calibration information, information relating to techniques for driving light sources  300 , information relating to addresses for lighting units  102 , information relating to effects run on lighting units  102 , and may other purposes as discussed further herein). The memory also may store one or more particular identifiers (e.g., a serial number, an address, etc.) that may be used either locally or on a system level to identify the lighting unit  102 . In various embodiments, such identifiers may be pre-programmed by a manufacturer or alterable by the manufacturer, for example, and may be either alterable or non-alterable thereafter (e.g., via some type of user interface located on the lighting unit, via one or more data or control signals received by the lighting unit, etc.). Alternatively, such identifiers may be determined at the time of initial use of the lighting unit in the field, and again may be alterable or non-alterable thereafter. The data storage facility  3700  may also be a disk, diskette, compact disk, random access memory, read only memory, SRAM, DRAM, database, data mart, data repository, cache, queue, or other facility for storing data, such as control instructions for a control facility  3500  for a lighting unit  102 . Data storage may occur locally with the lighting unit, in a socket or housing  800 , or remotely, such as on a server or in a remote database. In embodiments the data storage facility  3700  comprises a player that stores shows that can be triggered through a simple interface.  
      The drive facility  3800  may include drive hardware  3802  for driving one or more light sources  300 . In embodiments the drive hardware  3802  comprises a current sink, such as a switch  3900 , such as for turning on the current to a light source  300 . In embodiments the switch  3900  is under control of the processor  3600 , so that the switch  3900  can turn on or off in response to control signals. In embodiments the switch turns on and off in rapid pulses, such as in pulse width modulation of the current to the LEDs, which results in changes in the apparent intensity of the LED, based on the percentage of the duty cycle of the pulse width modulation technique during which the switch is turned on.  
      The drive hardware  3802  may include a voltage regulator  4000  for controlling voltage to a light source, such as to vary the intensity of the light coming from the light source  300 .  
      The drive hardware  3802  may include a feed-forward drive circuit  4100  such as described in the patent applications incorporated herein by reference.  
      The drive hardware  3802  may include an inductive loop drive circuit  4200  such as in the patent applications incorporated herein by reference.  
      Various embodiments of the present invention are directed generally to methods and apparatus for providing and controlling power to at least some types of loads, wherein overall power efficiency typically is improved and functional redundancy of components is significantly reduced as compared to conventional arrangements. In different aspects, implementations of methods and apparatus according to various embodiments of the invention generally involve significantly streamlined circuits having fewer components, higher overall power efficiencies, and smaller space requirements.  
      In some embodiments, a controlled predetermined power is provided to a load without requiring any feedback information from the load (i.e., without monitoring load voltage and/or current). Furthermore, in one aspect of these embodiments, no regulation of load voltage and/or load current is required. In another aspect of such embodiments in which feedback is not required, isolation components typically employed between a DC output voltage of a DC-DC converter (e.g., the load supply voltage) and a source of power derived from an AC line voltage (e.g., a high DC voltage input to the DC-DC converter) in some cases may be eliminated, thereby reducing the number of required circuit components. In yet another aspect, eliminating the need for a feedback loop generally increases circuit speed and avoids potentially challenging issues relating to feedback circuit stability.  
      Based on the foregoing concepts, one embodiment of the present invention is directed to a “feed-forward” driver for an LED-based light source. Such a feed-forward driver combines the functionality of a DC-DC converter and a light source controller, and is configured to control the intensity of light generated by the light source based on modulating the average power delivered to the light source in a given time period, without monitoring or regulating the voltage or current provided to the light source. In one aspect of this embodiment, the feed-forward driver is configured to store energy to and release energy from an energy transfer device using a “discontinuous mode” switching operation. This type of switching operation facilitates the transfer of a predictable quantum of energy per switching cycle, and hence a predictable controlled power delivery to the light source.  
      In embodiments the drive hardware  3802  includes at least one energy transfer element to store input energy based on an applied input voltage and to provide output energy to a load at an output voltage. The drive hardware  3802  may include at least one switch coupled to the at least one energy transfer element to control at least the input energy stored to the at least one energy transfer element and at least one switch controller configured to control the at least one switch, wherein the at least one switch controller does not receive any feedback information relating to the load to control the at least one switch.  
      As shown in  FIG. 1 , the lighting unit  102  also may include the processor  3600  that is configured to output one or more control signals to drive the light sources  300  so as to generate various apparent intensities of light from the light sources. For example, in one implementation, the processor  3600  may be configured to output at least one control signal for each light source so as to independently control the intensity of light generated by each light source. Some examples of control signals that may be generated by the processor to control the light sources include, but are not limited to, pulse modulated signals, pulse width modulated signals (PWM), pulse amplitude modulated signals (PAM), pulse displacement modulated signals, analog control signals (e.g., current control signals, voltage control signals), combinations and/or modulations of the foregoing signals, or other control signals. In one aspect, the processor  3600  may control other dedicated circuitry that in turn controls the light sources so as to vary their respective intensities.  
      Lighting systems in accordance with this specification can operate light sources  300  such as LEDs in an efficient manner. Typical LED performance characteristics depend on the amount of current drawn by the LED. The optimal efficacy may be obtained at a lower current than the level where maximum brightness occurs. LEDs are typically driven well above their most efficient operating current to increase the brightness delivered by the LED while maintaining a reasonable life expectancy. As a result, increased efficacy can be provided when the maximum current value of the PWM signal may be variable. For example, if the desired light output is less than the maximum required output the current maximum and/or the PWM signal width may be reduced. This may result in pulse amplitude modulation (PAM), for example; however, the width and amplitude of the current used to drive the LED may be varied to optimize the LED performance. In an embodiment, a lighting system may also be adapted to provide only amplitude control of the current through the LED. While many of the embodiments provided herein describe the use of PWM and PAM to drive the LEDs, one skilled in the art would appreciate that there are many techniques to accomplish the LED control described herein and, as such, the scope of the present invention is not limited by any one control technique. In embodiments, it is possible to use other techniques, such as pulse frequency modulation (PFM), or pulse displacement modulation (PDM), such as in combination with either or both of PWM and PAM.  
      Pulse width modulation (PWM) involves supplying a substantially constant current to the LEDs for particular periods of time. The shorter the time, or pulse-width, the less brightness an observer will observe in the resulting light. The human eye integrates the light it receives over a period of time and, even though the current through the LED may generate the same light level regardless of pulse duration, the eye will perceive short pulses as “dimmer” than longer pulses. The PWM technique is considered on of the preferred techniques for driving LEDs, although the present invention is not limited to such control techniques. When two or more colored LEDs are provided in a lighting system, the colors may be mixed and many variations of colors can be generated by changing the intensity, or perceived intensity, of the LEDs. In an embodiment, three colors of LEDs are presented (e.g., red, green and blue) and each of the colors is driven with PWM to vary its apparent intensity. This system allows for the generation of millions of colors (e.g., 16.7 million colors when 8-bit control is used on each of the PWM channels).  
      In an embodiment the LEDs are modulated with PWM as well as modulating the amplitude of the current driving the LEDs (Pulse Amplitude Modulation, or PAM). LED efficiency as a function of the input current increases to a maximum followed by decreasing efficiency. Typically, LEDs are driven at a current level beyond maximum efficiency to attain greater brightness while maintaining acceptable life expectancy. The objective is typically to maximize the light output from the LED while maintaining an acceptable lifetime. In an embodiment, the LEDs may be driven with a lower current maximum when lower intensities are desired. PWM may still be used, but the maximum current intensity may also be varied depending on the desired light output. For example, to decrease the intensity of the light output from a maximum operational point, the amplitude of the current may be decreased until the maximum efficiency is achieved. If further reductions in the LED brightness are desired the PWM activation may be reduced to reduce the apparent brightness.  
      One issue that may arise in connection with controlling multiple light sources  300  in the lighting unit  102 , and controlling multiple lighting units  102  in a lighting system relates to potentially perceptible differences in light output between substantially similar light sources. For example, given two virtually identical light sources being driven by respective identical control signals, the actual intensity of light output by each light source may be perceptibly different. Such a difference in light output may be attributed to various factors including, for example, slight manufacturing differences between the light sources, normal wear and tear over time of the light sources that may differently alter the respective spectrums of the generated radiation, etc. For purposes of the present discussion, light sources for which a particular relationship between a control signal and resulting intensity are not known are referred to as “uncalibrated” light sources.  
      The use of one or more uncalibrated light sources in the lighting unit  102  may result in generation of light having an unpredictable, or “uncalibrated,” color or color temperature. For example, consider a first lighting unit including a first uncalibrated red light source and a first uncalibrated blue light source, each controlled by a corresponding control signal having an adjustable parameter in a range of from zero to 255 (0-255). For purposes of this example, if the red control signal is set to zero, blue light is generated, whereas if the blue control signal is set to zero, red light is generated. However, if both control signals are varied from non-zero values, a variety of perceptibly different colors may be produced (e.g., in this example, at very least, many different shades of purple are possible). In particular, perhaps a particular desired color (e.g., lavender) is given by a red control signal having a value of 125 and a blue control signal having a value of 200.  
      Now consider a second lighting unit including a second uncalibrated red light source substantially similar to the first uncalibrated red light source of the first lighting unit, and a second uncalibrated blue light source substantially similar to the first uncalibrated blue light source of the first lighting unit. As discussed above, even if both of the uncalibrated red light sources are driven by respective identical control signals, the actual intensity of light output by each red light source may be perceptibly different. Similarly, even if both of the uncalibrated blue light sources are driven by respective identical control signals, the actual intensity of light output by each blue light source may be perceptibly different.  
      With the foregoing in mind, it should be appreciated that if multiple uncalibrated light sources are used in combination in lighting units to produce a mixed colored light as discussed above, the observed color (or color temperature) of light produced by different lighting units under identical control conditions may be perceivably different. Specifically, consider again the “lavender” example above; the “first lavender” produced by the first lighting unit with a red control signal of 125 and a blue control signal of 200 indeed may be perceptibly different than a “second lavender” produced by the second lighting unit with a red control signal of 125 and a blue control signal of 200. More generally, the first and second lighting units generate uncalibrated colors by virtue of their uncalibrated light sources.  
      In view of the foregoing, in one embodiment of the present invention, the lighting unit  102  includes a calibration facility to facilitate the generation of light having a calibrated (e.g., predictable, reproducible) color at any given time. In one aspect, the calibration facility is configured to adjust the light output of at least some light sources of the lighting unit so as to compensate for perceptible differences between similar light sources used in different lighting units.  
      For example, in one embodiment, the processor  3600  of the lighting unit  102  is configured to control one or more of the light sources  300  so as to output radiation at a calibrated intensity that substantially corresponds in a predetermined manner to a control signal for the light source(s). As a result of mixing radiation having different spectra and respective calibrated intensities, a calibrated color is produced. In one aspect of this embodiment, at least one calibration value for each light source is stored in the data facility  3700 , and the processor  3600  is programmed to apply the respective calibration values to the control signals for the corresponding light sources so as to generate the calibrated intensities.  
      In one aspect of this embodiment, one or more calibration values may be determined once (e.g., during a lighting unit manufacturing/testing phase) and stored in memory  3700  for use by the processor  3600 . In another aspect, the processor  3600  may be configured to derive one or more calibration values dynamically (e.g. from time to time) with the aid of one or more photosensors, for example. In various embodiments, the photosensor(s) may be one or more external components coupled to the lighting unit, or alternatively may be integrated as part of the lighting unit itself. A photosensor is one example of a signal source that may be integrated or otherwise associated with the lighting unit  102 , and monitored by the processor  3600  in connection with the operation of the lighting unit. Other examples of such signal sources are discussed further below, in connection with the signal source  8400 .  
      One exemplary method that may be implemented by the processor  3600  to derive one or more calibration values includes applying a reference control signal to a light source, and measuring (e.g., via one or more photosensors) an intensity of radiation thus generated by the light source. The processor may be programmed to then make a comparison of the measured intensity and at least one reference value (e.g., representing an intensity that nominally would be expected in response to the reference control signal). Based on such a comparison, the processor may determine one or more calibration values for the light source. In particular, the processor may derive a calibration value such that, when applied to the reference control signal, the light source outputs radiation having an intensity that corresponds to the reference value (i.e., the “expected” intensity).  
      In various aspects, one calibration value may be derived for an entire range of control signal/output intensities for a given light source. Alternatively, multiple calibration values may be derived for a given light source (i.e., a number of calibration value “samples” may be obtained) that are respectively applied over different control signal/output intensity ranges, to approximate a nonlinear calibration function in a piecewise linear manner.  
      Referring to  FIG. 25   c , typically an LED produces a narrow emission spectrum centered on a particular wavelength; i.e. a fixed color. Through the use of multiple LEDs and additive color mixing a variety of apparent colors can be produced, as described elsewhere herein.  
      In conventional LED-based light systems, constant current control is often preferred because of lifetime issues. Too much current can destroy an LED or curtail useful life. Too little current produces little light and is an inefficient or ineffective use of the LED.  
      The light output from a semiconductor illuminator may shift in wavelength as a result in changes in current. In general, the shift in output has been thought to be undesirable for most applications, since a stable light color is often preferred to an unstable one. Recent developments in LED light sources with higher power ratings (&gt;100 mA) have made it possible to operate LED systems effectively without supplying maximum current. Such operational ranges make it possible to provide LED-based lighting units  102  that have varying wavelength outputs as a function of current. Thus, different wavelengths of light can be provided by changing the current supplied to the LEDs to produce broader bandwidth colors (potentially covering an area, rather than just a point, in the chromaticity diagram of  FIG. 26 ), and to produce improved quality white light. This calibration technique not only changes the apparent intensity of the LEDs (reflecting the portion of the duty cycle of a pulse width modulation signal during which the LED is on as compared to the portion during which it is off), but also shifting the output wavelength or color. Current change can also broaden the narrow emission of the source, shifting the saturation of the light source towards a broader spectrum source. Thus, current control of LEDs allows controlled shift of wavelength for both control and calibration purposes.  
      In the visible spectrum, roughly 400 to 700 nm, the sensitivity of the eye varies according to wavelength. The sensitivity of the eye is least at the edges of that range and peaks at around 555 nm in the middle of the green.  
      Referring to  FIG. 25   b , a schematic diagram shows pulse shapes for a PWM signal. By rapidly changing the current and simultaneously adjusting the intensity via PWM, a broader spectrum light source can be produced.  FIG. 25   b  shows two PWM signals. The two PWM signals vary both in current level and width. The top one has a narrower pulse-width, but a higher current level than the bottom one. The result is that the narrower pulse offsets the increased current level in the top signal. As a result, depending on the adjustment of the two factors (on-time and current level) both light outputs could appear to be of similar brightness. The control is a balance between current level and the on time.  FIG. 25   a  shows an embodiment of a drive facility  3800  for simultaneous current control and on-off control under the control of a processor  3600 .  
      Controlled spectral shifting can also be used to adjust for differences between light sources  300 , such as differences between individual light sources  300  from the same vendor, or different lots, or “bins,” of light sources  300  from different vendors, such as to produce lighting units  102  that produce consistent color and intensity from unit to unit, notwithstanding the use of different kinds of light sources  300  in the respective lighting units  102 .  
       FIG. 25   c  shows the effect of changing both the current and adjusting the PWM for the purposes of creating a better quality white by shifting current and pulse-widths simultaneously and then mixing multiple sources, such as RG &amp; B, to produce a high quality white. The spectrum is built up by rapidly controlling the current and on-times to produce multiple shifted spectra. Thus, the original spectrum is shifted to a broader-spectrum by current shifts, while coordinated control of intensity is augmented by changes in PWM.  
      Current control can be provided with various embodiments, including feedback loops, such as using a light sensor as a signal source  8400 , or a lookup table or similar facility that stores light wavelength and intensity output as a function of various combinations of pulse-width modulation and pulse amplitude modulation.  
      In embodiments, a lighting system can produce saturated colors for one purpose (entertainment, mood, effects), while for another purpose it can produce a good quality variable white light whose color temperature can be varied along with the spectral properties. Thus a single fixture can have narrow bandwidth light sources for multicolor light applications and then can change to a current and PWM control mode to get broad spectra to make good white light or non-white light with broader spectrum color characteristics. In addition, the control mode can be combined with various optical facilities  400  described above to further control the light output from the system. In embodiments, the methods and systems can include a control loop and fast current sources to allow an operator to sweep about a broad spectrum. This could be done in a feed-forward system or with feedback to insure proper operation over a variety of conditions.  
      The control facility  3500  can switch between a current-control mode  2502  (which itself could be controlled by a PWM stream) and a separate PWM mode  2504 . Such a system can include simultaneous current control via PWM for wavelength and PWM control balanced to produce desired output intensity and color.  FIG. 25   a  shows a schematic diagram with one possible embodiment for creating the two control signals from a controller, such as a microprocessor to control one or more LEDs in a string. Multiple such strings can be used to create a light fixture that can vary in color (HSB) and spectrum based on the current and on-off control. The PWM signal can also be a PWM Digital-to-analog converter (DAC) such as those from Maxim and others. Note that the functions that correspond to particular values of output can be calibrated ahead of time by determining nominal values for the PWM signals and the resultant variations in the LED output. These can be stored in lookup tables or a function created that allows the mapping of desired values from LED control signals.  
      It may even be desirable to overdrive the LEDs. Although the currents would be above nominal operating parameters as described by the LED manufacturers, this can provide more light than normally feasible. The power source will also be drained faster, but the result can be a much brighter light source.  
      Modulation of lighting units  102  can include a data facility  3700 , such as a look-up table, that determines the current delivered to light sources  300  based on predetermined values stored in the data facility  3700  based on inputs, which may include inputs from signal sources  8400 , sensors, or the like.  
      It is also possible to drive light sources  300  with constant current, such as to produce a single color of light.  
      The methods and systems disclosed herein also include a variety of methods and systems for light control, including central control facilities  3500  as well as control facilities that are local to lighting units  102 . One grouping of control facilities  3500  includes dimmer controls, including both wired and wireless dimmer control. Traditional dimmers can be used with lighting units  102 , not just in the traditional way using voltage control or resistive load, but rather by using a processor to scale and control output by interpreting the levels of voltage. In combination with a style and interface that is familiar to most people because of the ubiquity of dimmer switches, one aspect of the present specification allows the position of a dimmer switch (linear or rotary) to indicate color temperature or intensity through a power cycle control. That is, the mode can change with each on or off cycle. A special switch can allow multiple modes without having to turn off the lights. An example of a product that uses this technique is the Color Dial, available from Color Kinetics.  
      Referring to  FIG. 26 , a chromaticity diagram shows a range of colors that can be viewed by the human eye. The gamut  2614  defines the range of colors that it is possible to produce by additively mixing colors from multiple sources, such as three LEDs. Green LEDs produce light in a green region  2612 , red LEDs produce light in a red region  2618  and blue LEDs produce light in a blue region  2620 . Mixing these colors produces mixed light output, such as in the overlapping areas between the regions, including those for orange, purple and other mixed light colors. Mixing all three sources produces white light, such as along a black body curve  1310 . Different mixtures produce different color temperatures of white light along or near the black body curve  2610 . Typically an LED produces a narrow emission spectrum centered on a particular wavelength; i.e. a fixed color and a single point on the chromaticity diagram. Through the use of multiple LEDs and additive color mixing a variety of apparent colors can be produced. In embodiments the gamut  2614  may be determined by a program stored on the data storage facility  3700 , rather than by the light output capacities of light sources  300 . For example, a more limited gamut  2614  may be defined to ensure that the colors within the gamut  2614  can be consistently produced by all light sources  300  across a wide range of lighting units  102 , even accounting for lower quality light sources  300 . Thus, such a program can improve consistency of lighting units  102  from unit to unit.  
      The photopic response of the human eye varies across different colors for a given intensity of light radiation. For example, the human eye may tend to respond more effectively to green light than to blue light of the same intensity. As a result, a lighting unit  102  may seem dimmer if turned on blue than the same lighting unit  102  seems when turned on green. However, in installations of multiple lighting units  102 , users may desire that different lighting units  102  have similar intensities when turned on, rather than having some lighting units  102  appear dim while others appear bright. A program can be stored on a data storage facility  3700  for use by the processor  3600  to adjust the pulses of current delivered to the light sources  300  (and in turn the apparent intensity of the light sources) based on the predicted photopic response of the human eye to the color of light that is called for by the processor  3600  at any given time. A lookup table or similar facility can associate each color with a particular intensity scale, so that each color can be scaled relative to all others in apparent intensity. The result is that lighting units  102  can be caused to deliver light output along isoluminance curves (similar to topographic lines on a map) throughout the gamut  2614 , where each curve represents a common level of apparent light output of the lighting unit  102 . The program can account for the particular spectral output characteristics of the types of light sources  300  that make up a particular type of lighting unit  102  and can account for differences in the light sources  300  between different lighting units  102 , so that lighting units  102  using different light sources  300 , such as from different vendors, can nevertheless provide light output of consistent intensity at any given color.  
      A control interface  4900  may be provided for a lighting unit  102 . The interface can vary in complexity, ranging from having minimal control, such as “on-off” control and dimming, to much more extensive control, such as producing elaborate shows and effects using a graphical user interface for authoring them and using network systems to deliver the shows and effects to lighting units  102  deployed in complex geometries.  
      Referring to  FIG. 27   a , it is desirable to provide a light system manager  5000  to manage a plurality of lighting units  102  or light systems  100 .  
      Referring to  FIG. 27   b , the light system manager  5000  is provided, which may consist of a combination of hardware and software components. Included is a mapping facility  5002  for mapping the locations of a plurality of light systems. The mapping facility may use various techniques for discovering and mapping lights, such as described herein or as known to those of skill in the art. Also provided is a light system composer  5004  for composing one or more lighting shows that can be displayed on a light system. The authoring of the shows may be based on geometry and an object-oriented programming approach, such as the geometry of the light systems that are discovered and mapped using the mapping facility, according to various methods and systems disclosed herein or known in the art. Also provided is a light system engine, for playing lighting shows by executing code for lighting shows and delivering lighting control signals, such as to one or more lighting systems, or to related systems, such as power/data systems, that govern lighting systems. Further details of the light system manager  5000 , mapping facility  5002 , light system composer  5004  and light system engine  5008  are provided herein.  
      The light system manager  5000 , mapping facility  5002 , light system composer  5004  and light system engine  5008  may be provided through a combination of computer hardware, telecommunications hardware and computer software components. The different components may be provided on a single computer system or distributed among separate computer systems.  
      Referring to  FIG. 28 , in an embodiment, the mapping facility  5002  and the light system composer  5004  are provided on an authoring computer  5010 . The authoring computer  5010  may be a conventional computer, such as a personal computer. In embodiments the authoring computer  5010  includes conventional personal computer components, such as a graphical user interface, keyboard, operating system, memory, and communications capability. In embodiments the authoring computer  5010  operates with a development environment with a graphical user interface, such as a Windows environment. The authoring computer  5010  may be connected to a network, such as by any conventional communications connection, such as a wire, data connection, wireless connection, network card, bus, Ethernet connection, Firewire, 802.11 facility, Bluetooth, or other connection. In embodiments, such as in  FIG. 28 , the authoring computer  5010  is provided with an Ethernet connection, such as via an Ethernet switch  5102 , so that it can communicate with other Ethernet-based devices, optionally including the light system engine  5008 , a light system itself (enabled for receiving instructions from the authoring computer  5010 ), or a power/data supply (PDS)  1758  that supplies power and/or data to a light system  100  comprised of one or more lighting units  102 . The mapping facility  5002  and the light system composer  5004  may comprise software applications running on the authoring computer  5010 .  
      Referring still to  FIG. 28 , in an architecture for delivering control systems for complex shows to one or more light systems, shows that are composed using the authoring computer  5010  are delivered via an Ethernet connection through one or more Ethernet switches to the light system engine  5008 . The light system engine  5008  downloads the shows composed by the light system composer  5004  and plays them, generating lighting control signals for light systems. In embodiments, the lighting control signals are relayed by an Ethernet switch to one or more power/data supplies and are in turn relayed to light systems that are equipped to execute the instructions, such as by turning LEDs on or off, controlling their color or color temperature, changing their hue, intensity, or saturation, or the like. In embodiments the power/data supply may be programmed to receive lighting shows directly from the light system composer  5004 . In embodiments a bridge may be programmed to convert signals from the format of the light system engine  5008  to a conventional format, such as DMX or DALI signals used for entertainment lighting.  
      Referring to  FIG. 29 , in embodiments the lighting shows composed using the light system composer  5004  are compiled into simple scripts that are embodied as XML documents. The XML documents can be transmitted rapidly over Ethernet connections. In embodiments, the XML documents are read by an XML parser of the light system engine  5008 . Using XML documents to transmit lighting shows allows the combination of lighting shows with other types of programming instructions. For example, an XML document type definition may include not only XML instructions for a lighting show to be executed through the light system engine  5008 , but also XML with instructions for another computer system, such as a sound system, and entertainment system, a multimedia system, a video system, an audio system, a sound-effect system, a smoke effect system, a vapor effect system, a dry-ice effect system, another lighting system, a security system, an information system, a sensor-feedback system, a sensor system, a browser, a network, a server, a wireless computer system, a building information technology system, or a communication system.  
      Thus, methods and systems provided herein include providing a light system engine for relaying control signals to a plurality of light systems, wherein the light system engine plays back shows. The light system engine  5008  may include a processor, a data facility, an operating system and a communication facility. The light system engine  5008  may be configured to communicate with a DALI or DMX lighting control facility. In embodiments, the light system engine communicates with a lighting control facility that operates with a serial communication protocol. In embodiments the lighting control facility is a power/data supply for a lighting unit  102 .  
      In embodiments, the light system engine  5008  executes lighting shows downloaded from the light system composer  5004 . In embodiments the shows are delivered as XML files from the light system composer  5004  to the light system engine  5008 . In embodiment the shows are delivered to the light system engine over a network. In embodiments the shows are delivered over an Ethernet facility. In embodiments the shows are delivered over a wireless facility. In embodiments the shows are delivered over a Firewire facility. In embodiments shows are delivered over the Internet.  
      In embodiments lighting shows composed by the light system composer  5004  can be combined with other files from another computer system, such as one that includes an XML parser that parses an XML document output by the light system composer  5004  along with XML elements relevant to the other computer. In embodiments lighting shows are combined by adding additional elements to an XML file that contains a lighting show. In embodiments the other computer system comprises a browser and the user of the browser can edit the XML file using the browser to edit the lighting show generated by the lighting show composer. In embodiments the light system engine  5008  includes a server, wherein the server is capable of receiving data over the Internet. In embodiments the light system engine  5008  is capable of handling multiple zones of light systems, wherein each zone of light systems has a distinct mapping. In embodiments the multiple zones are synchronized using the internal clock of the light system engine  5008 .  
      The methods and systems included herein include methods and systems for providing a mapping facility  5002  of the light system manager  5000  for mapping locations of a plurality of light systems. In embodiments, the mapping system discovers lighting systems in an environment, using techniques described above. In embodiments, the mapping facility then maps light systems in a two-dimensional space, such as using a graphical user interface.  
      In embodiments of the invention, the light system engine  5008  comprises a personal computer with a Linux operating system. In embodiments the light system engine is associated with a bridge to a DMX or DALI system.  
      A light system  100  may include a network interface  4902  for delivering data from a control facility  3500  to one or more light systems  100 , which may include one or more lighting units  102 . The term “network” as used herein refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transport of information (e.g. for device control, data storage, data exchange, etc.) between any two or more devices and/or among multiple devices coupled to the network. As should be readily appreciated, various implementations of networks suitable for interconnecting multiple devices may include any of a variety of network topologies and employ any of a variety of communication protocols. Additionally, in various networks according to the present invention, any one connection between two devices may represent a dedicated connection between the two systems, or alternatively a non-dedicated connection. In addition to carrying information intended for the two devices, such a non-dedicated connection may carry information not necessarily intended for either of the two devices (e.g., an open network connection). Furthermore, it should be readily appreciated that various networks of devices as discussed herein may employ one or more wireless, wire/cable, and/or fiber optic links to facilitate information transport throughout the network.  
       FIG. 28  illustrates one of many possible examples of a networked lighting system  100  in which a number of lighting units  102  are coupled together to form the networked lighting system.  FIG. 30  depicts another networked configuration for a lighting system  100 .  
      The networked lighting system  100  may be configured flexibly to include one or more user interfaces  4908 , as well as one or more signal sources  8400  such as sensors/transducers  8402 . For example, one or more user interfaces and/or one or more signal sources such as sensors/transducers  8402  (as discussed above in connection with  FIG. 2 ) may be associated with any one or more of the lighting units  102  of the networked lighting system  100 . Alternatively (or in addition to the foregoing), one or more user interfaces  4908  and/or one or more signal sources  8400  may be implemented as “stand alone” components in the networked lighting system  100 . Whether stand alone components or particularly associated with one or more lighting units  102 , these devices may be “shared” by the lighting units of the networked lighting system  100 . Stated differently, one or more user interfaces  4908  and/or one or more signal sources  8400  such as sensors/transducers  8402  may constitute “shared resources” in the networked lighting system  100  that may be used in connection with controlling any one or more of the lighting units  102  of the system  100 .  
      The lighting system  100  may include one or more lighting unit controllers (LUCs)  3500   a ,  3500   b ,  3500   c ,  3500   d  for lighting units  102 , wherein each LUC is responsible for communicating with and generally controlling one or more lighting units  102  coupled to it. Different numbers of lighting units  102  may be coupled to a given LUC in a variety of different configurations using a variety of different communication media and protocols.  
      Each LUC in turn may be coupled to a central control facility  3500  that is configured to communicate with one or more LUCs. Although  FIG. 2  shows four LUCs coupled to the central controller  3500  via a switching or coupling device  3004 , it should be appreciated that according to various embodiments, different numbers of LUCs may be coupled to the central controller  3500 . Additionally, according to various embodiments of the present invention, the LUCs and the central controller  3500  may be coupled together in a variety of configurations using a variety of different communication media and protocols to form the networked lighting system  100 . Moreover, it should be appreciated that the interconnection of LUCs  3500   a ,  3500   b ,  3500   c ,  3500   d  and the central controller  3500 , and the interconnection of lighting units  102  to respective LUCs, may be accomplished in different manners (e.g., using different configurations, communication media, and protocols).  
      For example, according to one embodiment of the present invention, the central controller  3500  shown in  FIG. 30  may be configured to implement Ethernet-based communications with the LUCs, and in turn the LUCs may be configured to implement DMX-based communications with the lighting units  102 . In particular, in one aspect of this embodiment, each LUC may be configured as an addressable Ethernet-based controller and accordingly may be identifiable to the central controller  3500  via a particular unique address (or a unique group of addresses) using an Ethernet-based protocol. In this manner, the central controller  3500  may be configured to support Ethernet communications throughout the network of coupled LUCs, and each LUC may respond to those communications intended for it. In turn, each LUC may communicate lighting control information to one or more lighting units coupled to it, for example, via a DMX protocol, based on the Ethernet communications with the central controller  3500 .  
      More specifically, according to one embodiment, the LUCs  3500   a ,  3500   b ,  3500   c  and  3500   d  shown in  FIG. 30  may be configured to be “intelligent” in that the central controller  3500  may be configured to communicate higher level commands to the LUCs that need to be interpreted by the LUCs before lighting control information can be forwarded to the lighting units  102 . For example, a lighting system operator may want to generate a color changing effect that varies colors from lighting unit to lighting unit in such a way as to generate the appearance of a propagating rainbow of colors (“rainbow chase”), given a particular placement of lighting units with respect to one another. In this example, the operator may provide a simple instruction to the central controller  3500  to accomplish this, and in turn the central controller may communicate to one or more LUCs using an Ethernet-based protocol high-level command to generate a “rainbow chase.” The command may contain timing, intensity, hue, saturation or other relevant information, for example. When a given LUC receives such a command, it may then interpret the command so as to generate the appropriate lighting control signals which it then communicates using a DMX protocol via any of a variety of signaling techniques (e.g., PWM) to one or more lighting units that it controls.  
      It should again be appreciated that the foregoing example of using multiple different communication implementations (e.g., Ethernet/DMX) in a lighting system according to one embodiment of the present invention is for purposes of illustration only, and that the invention is not limited to this particular example.  
      In embodiments the central controller  3500  may be a network controller that controls other functions, such as a home network, business enterprise network, building network, or other network.  
      In embodiments a switch, such as a wall switch, can include a processor  3600 , memory  3700  and a communications port for receiving data. The switch can be linked to a network, such as an office network, Internet, or home network. Each switch can be an intelligent device that responds to communication signals via the communications port to provide control of any lighting units  102  from any location where another switch or intelligent device may be located. Such a switch can be integrated through smart interfaces and networks to trigger shows (such as using a lighting control player, such as iPlayer 2 available from Color Kinetics) as with a lighting controller such as a ColorDial from Color Kinetics. Thus, the switch can be programmed with light shows to create various aesthetic, utilitarian or entertainment effects, of white or non-white colors. In embodiments, an operator of a system can process, create or download shows, including from an external source such as the Internet. Shows can be sent to the switch over a communication facility of any kind. Various switches can be programmed to play back and control any given lighting unit  102 . In embodiments, settings can be controlled through a network or other interface, such as a web interface.  
      A switch with a processor  3600  and memory  3700  can be used to enable upgradeable lighting units  102 . Thus, lighting units  102  with different capabilities, shows, or features can be supplied, allowing users to upgrade to different capabilities, as with different versions of commercial software programs. Upgrade possibilities include firmware to add features, fix bugs, improve performance, change protocols, add capability and provide compatibility, among others.  
      In embodiments a control facility  3500  may be based on stored modes and a power cycle event. The operator can store modes for lighting control, such as on a memory  3700 . The system can then look for a power event, such as turning the power on or off. When there is a power event the system changes mode. The mode can be a resting mode, with no signal to the lighting unit  102 , or it can be any of a variety of different modes, such as a steady color change, a flashing mode, a fixed color mode, or modes of different intensity. Modes can include white and non-white illumination modes. The modes can be configured in a cycle, so that upon a mode change, the next stored mode is retrieved from memory  3700  and signals for that mode are delivered to the lighting unit  102 , such as using a switch, slide, dial, or dimmer. The system can take an input signal, such as from the switch. Depending on the current mode, the input signal from the switch can be used to generate a different control signal. For example, if the mode is a steady color change, the input from the dimmer could accelerate of decelerate the rate of change. If the mode were a single color, then the dimmer signal could change the mode by increasing or decreasing the intensity of light. Of course, system could take multiple inputs from multiple switches, dials, dimmers, sliders or the like, to provide more modulation of the different modes. Finally, the modulated signal can be sent to the lighting unit  102 .  
      In embodiments a system with stored modes can take input, such as from a signal source  8400 , such as a sensor, a computer, or other signal source. The system can determine the mode, such as based on a cycle of modes, or by recalling modes from memory, including based on the nature of the signal from the signal source  8400 . Then system can generate a control signal for a lighting unit, based on the mode.  
      Referring to  FIG. 31   a , the methods and systems disclosed herein may further comprise disposing a plurality of lighting units  102  in a serial configuration and controlling all of them by a stream of data to respective processors  3600 , such as ASICS, of each of them, wherein each lighting unit  102  responds to the first unmodified bit of data in the stream, modifies that bit of data, and transmits the stream to the next ASIC. Using such a serial addressing protocol, data can be addressed to lighting units  102  based on their location in a series of lighting units  102 , rather than requiring knowledge of the exact physical location of each lighting unit  102 .  
      Methods and system provided herein also include providing a self-healing lighting system, which may include providing a plurality of lighting units in a system, each having a plurality of light sources; providing at least one processor associated with at least some of the lighting units for controlling the lighting units; providing a network facility for addressing data to each of the lighting units; providing a diagnostic facility for identifying a problem with a lighting unit; and providing a healing facility for modifying the actions of at least one processor to automatically correct the problem identified by the diagnostic facility.  
      A lighting unit controller according to the present invention may include a unique address such that the 208 can be identified and communicated with. The LUC may also include a universe address such that the lighting unit controller can be grouped with other controllers or systems and addressed information can be communicated to the group of systems. The lighting unit controller may also have a broadcast address, or otherwise listen to general commands provided to many or all associated systems.  
      Referring to  FIG. 31   b , the network interface  4900  may include a network topology with a control facility  3500  and multiple lighting units  102  disposed on the network in a hub-router configuration. Referring to  FIG. 31   c , the lighting units  102  can be disposed along a high-speed serial bus for receiving control signals from a data facility  3500 .  
      A lighting unit  102  may include a physical data interface  4904  for receiving data, such as from another lighting unit  102 , from a signal source  8400 , from a user interface  4902 , or from a control facility  3500 . Referring to  FIG. 32 , the lighting unit  102  may include one or more communication ports  4904  to facilitate coupling of the lighting unit  102  to any of a variety of other devices. For example, one or more communication ports  4904  may facilitate coupling multiple lighting units together as a networked lighting system, in which at least some of the lighting units are addressable (e.g., have particular identifiers or addresses) and are responsive to particular data transported across the network.  
      In embodiments the communication port  4904  can receive a data cable, such as a standard CAT 5 cable type used for networking. Thus, the lighting unit  102  can receive data, such as from a network. By allowing connection of the lighting unit  102  to a communications port  4904 , the system allows a lighting designer or installer to send data to a plurality of lighting units  102  to put them in common modes of control and illumination, providing more consistency to the lighting of the overall environment.  
       FIG. 33  shows various embodiments of physical data interfaces  4902 .  FIG. 33   a  shows an embodiment arranged in a wireless network arrangement, using a wireless data interface as the physical data interface, such as a radio frequency interface, infrared interface, Bluetooth interface, 802.11 interface, or other wireless interface. In embodiments the wireless arrangement is a peer-to-peer arrangement. In embodiments such as  FIG. 33   b , the arrangement is a master-slave arrangement, where on lighting unit  102  controls other lighting units  102  in close proximity.  FIG. 33   c  a retrofit lighting unit  102  with a communication port  4904 .  FIG. 33   e  shows a socket  3302  or fixture for receiving a lighting unit  102 . In this case the socket  3302  includes a processor  3600 , such as to providing control signals to the lighting unit  102 . The socket  3600  can be connected to a control interface  4900 , such as a network, so that it can receive signals, such as from a control facility  3500 . Thus, the socket  3302  can serve as a lighting unit controller. By placing control in the socket  3302 , it is possible for a lighting designer or installer to provide control signals to a known location, regardless of what bulbs are removed or replaced into the socket  3302 . Thus, an environmental lighting system can be arranged by the sockets  3302 , then any different lighting units  102  can be installed, responsive to control signals sent to the respective sockets  3302 . Sockets  3302  can be configured to receive any kind of light bulb, including incandescent, fluorescent, halogen, metal halide, LED-based lights, or the like. Thus, intelligence can be provided by the processor  3600  to a conventional socket. In embodiments, data can be provided over power lines, thus avoiding the need to rewire the environment, using power line carrier techniques as known in the art, the X10 system being one such example, and the HomeTouch system being another.  
      In the preceding embodiments, a fixture or network can give a lighting unit  102  a command to set to a particular look including, color, color temperature, intensity, saturation, and spectral properties. Thus, when the designer sets the original design he or she may specify a set of particular light bulb parameters so that when a lighting unit  102  is replaced the fixture or network can perform a startup routine that initializes that lighting unit  102  to a particular set of values which are then controlled. In embodiments, the lighting unit  102  identifies itself to the network when the power is turned on. The lighting unit  102  or fixture or socket  3302  can be assigned an address by the central control facility  3500 , via a network interface  4900 . Thus, there is an address associated with the fixture or socket  3302 , and the lighting unit  102  control corresponds to that address. The lighting unit  102  parameters can be set in memory  3700 , residing in either the lighting unit  102 , socket  3302  or fixture, cable termination  3304  or in a central control facility  3500 . The lighting unit  102  can now be set to those parameters. From then on, when the lighting unit  102  is powered up it receives a simple command value already set within the set of parameters chosen by the designer.  
      As used herein, the terms “wired” transmission and or communication should be understood to encompass wire, cable, optical, or any other type of communication where the devices are physically connected. As used herein, the terms “wireless” transmission and or communication should be understood to encompass acoustical, RF, microwave, IR, and all other communication and or transmission systems were the devices are not physically connected.  
      Referring to  FIG. 33   e , the physical data interface  4904  can include a processor included in an end of a cable  3304 , so that the cable itself is a lighting unit controller, such as to ensure that as lighting units  102  are replaced, any lighting unit attached to that cable  3304  will respond to signals intended to be addressed to locations of that cable.  3304 . This is helpful in environments like airline cabins, where maintenance staff may not have time to enter address information for replacement lighting units  102  when earlier units fail.  
      A lighting unit  102  can respond to input from a user interface  4908 . The term “user interface” as used herein refers to an interface between a human user or operator and one or more devices that enables communication between the user and the device(s). Examples of user interfaces that may be employed in various implementations of the present invention include, but are not limited to, switches, human-machine interfaces, operator interfaces, potentiometers, buttons, dials, sliders, a mouse, keyboard, keypad, various types of game controllers (e.g., joysticks), track balls, display screens, various types of graphical user interfaces (GUIs), touch screens, microphones and other types of sensors that may receive some form of human-generated stimulus and generate a signal in response thereto.  
      In another aspect, as also shown in  FIG. 2 , the lighting unit  102  optionally may include one or more user interfaces  4908  that are provided to facilitate any of a number of user-selectable settings or functions (e.g., generally controlling the light output of the lighting unit  102 , changing and/or selecting various pre-programmed lighting effects to be generated by the lighting unit, changing and/or selecting various parameters of selected lighting effects, setting particular identifiers such as addresses or serial numbers for the lighting unit, etc.). In various embodiments, the communication between the user interface  4908  and the lighting unit may be accomplished through wire or cable, or wireless transmission.  
      In one implementation, the processor  3600  of the lighting unit monitors the user interface  4908  and controls one or more of the light sources  300  based at least in part on a user&#39;s operation of the interface. For example, the processor  3600  may be configured to respond to operation of the user interface by originating one or more control signals for controlling one or more of the light sources. Alternatively, the processor  3600  may be configured to respond by selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources.  
      In particular, in one implementation, the user interface  4908  may constitute one or more switches (e.g., a standard wall switch) that interrupt power to the processor  3600 . In one aspect of this implementation, the processor  3600  is configured to monitor the power as controlled by the user interface, and in turn control one or more of the light sources  300  based at least in part on a duration of a power interruption caused by operation of the user interface. As discussed above, the processor may be particularly configured to respond to a predetermined duration of a power interruption by, for example, selecting one or more pre-programmed control signals stored in memory, modifying control signals generated by executing a lighting program, selecting and executing a new lighting program from memory, or otherwise affecting the radiation generated by one or more of the light sources.  
      Referring to  FIG. 34  simple user interfaces can be used to trigger control signals.  FIG. 34   a  shows a push button  3402  that triggers stored modes when pressed.  FIG. 34   b  and  FIG. 34   c  show user interfaces  4908  involving slides  3404  that can change the intensity or color, depending on the mode. A dual slide is shown in  FIG. 34   c , where one slide  3404  can adjust color and the other can adjust intensity, or the like.  FIG. 34   d  and  FIG. 34   e  show dials  3408 . The dial can trigger stored modes or adjust color or intensity of light. The dual-dial embodiment of  FIG. 34   e  can include one dial for color and another for intensity.  FIG. 34   f  shows a dial  3408  that includes a processor  3600  and memory  3700 , so that the user interface can provide basic instructions, such as for stored modes, but the user interface  4908  also reacts to instructions from a central control facility  3500 .  FIG. 34   g  shows a dipswitch  3410 , which can beg used to set simple modes of a lighting unit  102 .  FIG. 34   h  shows a microphone  3412 , such as for a voice recognition facility interface to a lighting unit  102 , such as to trigger lighting by voice interaction. In embodiments such as  FIG. 34   a , the slide can provide voltage input to a lighting unit  102 , and the switch can allow the user to switch between modes of operation, such as by selecting a color wash, a specific color or color temperature, a flashing series of colors, or the like.  
      In various embodiments the slides, switches, dials, dipswitches and the like can be used to control a wide range of variables, such as color, color temperature, intensity, hue, and triggering of lighting shows of varying attributes.  
      In other embodiments of the present invention it may be desirable to limit user control. Lighting designers, interior decorators and architects often prefer to create a certain look to their environment and wish to have it remain that way over time. Unfortunately, over time, the maintenance of an environment, which includes light bulb replacement, often means that a lighting unit, such as a bulb, is selected whose properties differ from the original design. This may include differing wattages, color temperatures, spectral properties, or other characteristics. It is desirable to have facilities for improving the designer&#39;s control over future lighting of an environment.  
      Referring to  FIG. 34   i , in embodiments a dial allows a user to select one or more colors or color temperatures from a scale  3414 . For example, the scale  3414  cand include different color temperatures of white light. The lighting designer can specify use of a particular color temperature of light, which the installer can select by setting the right position on the scale  3414  with the dial. A slide mechanism can be used like the dial to set a particular color temperature of white light, or to select a particular color of non-white light, in either case on a scale. Again, the designer can specify a particular setting, and the installer can set it according to the design plan. Providing adjustable lighting units  102  offers designers and installers much greater control over the correct maintenance of the lighting of the environment.  
      In embodiments, the fixture, socket  3302  or lighting unit  102  can command color setting at installation, either a new setting or a fine adjustment to provide precise color control. In embodiments, the lighting unit  102  allows color temperature control as described elsewhere. The lighting unit  102  is settable, but the fixture itself stores an instruction or value for the setting of a particular color temperature or color. Since the fixture is set, the designer or architect can insure that all settable lighting units  102  will be set correctly when they are installed or replaced. An addressable fixture can be accomplished through a cable connection where the distal end of the cable, at the fixture, has a value programmed or set. The value is set through storage in memory  3700  or over the power lines. A physical connection can be made with a small handheld device, such as a Zapi available from Color Kinetics, to create and set the set of parameters for that fixture and others. If the environment changes over time, as for example during a remodeling, then those values can be updated and changed to reflect a new look for the environment. A person could either go from fixture to fixture to reset those values or change those parameters remotely to set an entire installation quickly. Once the area is remodeled or repainted, as in the lobby of a hotel for example, the color temperature or color can be reset and, for example, have all lighting units  102  in the lobby set to white light of 3500K. Then, in the future, is any lighting unit  102  is replaced or upgraded, any bulb plugged in can be set to that new value. Changes to the installation parameters can be done in various ways, such as by network commands, or wireless communication, such as RF or IR communication.  
      In various embodiments, the setting can occur in the fixture or socket  3302 , in the distal end of a cable  3304 , in the proximal end of the cable  3304 , or in a central control facility  3500 . The setting can be a piece of memory  3700  embedded in any of those elements with a facility for reading out the data upon startup of the lighting unit  102 .  
      In other embodiments it may be desirable to prevent or deter user adjustment. A lighting unit  102  can be programmed to allow adjustment and changes to parameters by a lighting designer or installer, but not by other users. Such systems can incorporate a lockout facility to prevent others from easily changing the settings. This can take the form of memory  3700  to store the current state but allow only a password-enabled user to make changes. One embodiment is a lighting unit  102  that is connected to a network or to a device that allows access to the lighting unit  102  or network. The device can be an authorized device whose initial communication establishes trust between two devices or between the device and network. This device can, once having established the connection, allow for the selection or modification of pattern, color, effect or relationship between other devices such as ambient sensors or external devices. The system can store modes, such as in memory  3700 . The system can detect a user event, such as an attempt by the user to change modes, such as sending an instruction over a network or wireless device. The system queries whether the user is authorized to change the mode of the lighting unit  102 , such as by asking for a password, searching for a stored password, or checking a device identifier for the device through which the user is seeking to change the mode of the lighting unit  102 . If the user is not authorized, then the system maintains the previous mode and optionally notifies the lighting designer, installer, or other individual of the unauthorized attempt to change the mode. If the user is authorized, then the user is allowed to change the mode. Facilities for allowing only authorized users to trigger events are widely known in the arts of computer programming, and any such facilities can be used with a processor  3600  and memory  3700  used with a lighting unit  102 .  
      In other embodiments, the lighting designer can specify changes in color over time or based on time of day or season of year. It is beneficial for a lighting unit  102  to measure the amount of time that it has been on and store information in a compact form as to its lighting history. This provides a useful history of the use of the light and can be correlated to use lifetime and power draw, among other measurements. An intelligent networked lighting unit  102  can store a wide variety of useful information about its own state over time and the environmental state of its surroundings. A lighting unit can store a histogram, a chart representing value and time of lighting over time. The histogram can be stored in memory  3700 . A histogram can chart on time versus off time for a lighting unit  102 . A histogram can be correlated to other data, such as room habitation, to develop models of patterns of use, which can then be tied into a central control facility  3500 , such as integrated with a building control system.  
      In embodiments a user interface  4908  instructs a lighting system  100  to produce a desired mixed light output. The user interface can be a remote control, a network interface, a dipswitch, a computer, such as a laptop computer, a personal computer, a network computer, or a personal digital assistant, an interface for programming an on-board memory of the illumination system, a wireless interface, a digital facility, a remote control, a receiver, a transceiver, a network interface, a personal computer, a handheld computer, a push button, a dial, a toggle/membrane switch, an actuator that actuates when one part of a housing is rotated relative to another, a motion sensor, an insulating strip that is removed to allow power to a unit, an electrical charge to turn a unit on, or a magnetic interface such as a small reed-relay or Hall-effect sensor that can be incorporated so when a magnetic material is brought within the proximity of the device it completes a power circuit.  
      Referring to  FIG. 35   a , a user interface  4908  may include a browser  3550  running on a computer. The browser  3550  may be used to trigger shows, such as ones stored locally at a power data supply  1758  connected to a network, such as through an Ethernet switch. In general a computer may supply a graphical user interface for authoring and triggering shows, as described in more detail below.  FIG. 35   b  shows a graphical user interface  3502  for a playback controller that can control the playback of shows, such as ones stored in memory  3700  of a lighting system  100 .  
      In embodiments a keypad  3650  may be used to store control signals for lighting shows. Buttons  3652  on the keypad  3650  may be used to trigger stored shows, such as to be delivered directly to lighting units  102  or to deliver them across a network, such as in the Ethernet configuration of  FIG. 36 .  
      In embodiments it may be important to provide an addressing facility  6600  for providing an address to a lighting unit  102  or light system  100 . An address permits a particular lighting unit  102  to be identified among a group of lighting units  102  or a group of lighting units  102  to be identified among a larger group, or a group of other devices deployed on a common network. An address in turn permits use of the mapping facility  5002  for mapping locations of lighting units  102  according to their unique identifiers or addresses. Once locations are mapped, it is possible to deliver control signals to the lighting units  102  in desired sequences to create complex effects, such as color-chasing rainbows, or the like, based on their correct locations in the world.  
      The term “addressable” is used herein to include a device (e.g., a light source in general, a lighting unit or fixture, a controller or processor associated with one or more light sources or lighting units, other non-lighting related devices, etc.) that is configured to receive information (e.g., data) intended for multiple devices, including itself, and to selectively respond to particular information intended for it. The term “addressable” often is used in connection with a networked environment (or a “network,” discussed further below), in which multiple devices are coupled together via some communications medium or media.  
      In one implementation, one or more devices coupled to a network may serve as a controller for one or more other devices coupled to the network (e.g., in a master/slave relationship). In another implementation, a networked environment may include one or more dedicated controllers that are configured to control one or more of the devices coupled to the network. Generally, multiple devices coupled to the network each may have access to data that is present on the communications medium or media; however, a given device may be “addressable” in that it is configured to selectively exchange data with (i.e., receive data from and/or transmit data to) the network, based, for example, on one or more particular identifiers (e.g., “addresses”) assigned to it.  
      More specifically, one embodiment of the present invention is directed to a system of multiple controllable lighting units coupled together in any of a variety of configurations to form a networked lighting system. In one aspect of this embodiment, each lighting unit has one or more unique identifiers (e.g., a serial number, a network address, etc.) that may be pre-programmed at the time of manufacture and/or installation of the lighting unit, wherein the identifiers facilitate the communication of information between respective lighting units and one or more lighting system controllers. In another aspect of this embodiment, each lighting unit  102  may be flexibly deployed in a variety of physical configurations with respect to other lighting units of the system, depending on the needs of a given installation.  
      One issue that may arise in such a system of multiple controllable lighting units  102  is that upon deployment of the lighting units  102  for a given installation, it is in some cases challenging to configure one or more system controllers a priori with some type of mapping information that provides a relationship between the identifier for each lighting unit  102  and its physical location relative to other lighting units  102  in the system. In particular, a lighting system designer/installer may desire to purchase a number of individual lighting units each pre-programmed with a unique identifier (e.g., serial number), and then flexibly deploy and interconnect the lighting units in any of a variety of configurations to implement a networked lighting system. At some point before operation, however, the system needs to know the identifiers of the controllable lighting units deployed, and preferably their physical location relative to other units in the system, so that each unit may be appropriately controlled to realize system-wide lighting effects.  
      Referring to  FIG. 37 , one way to accomplish mapping is to have one or more system operators and/or programmers manually create one or more custom system configuration files  3700  containing the individual identifiers  3702  for each lighting unit  102  and corresponding mapping information that provides some means of identifying the relative physical locations  3708  of lighting units  102  in the system. Configuration files  3700  can include other attributes, such as the positions lit by a lighting unit  102 , as well as the positions of the lighting units  102  themselves. As the number of lighting units  192  deployed in a given system increases and the physical geometry of the system becomes more complex, however, and the process of creating manual configuration files can quickly become unwieldy. Rather than manually entering configuration data, it is desirable to have other methods of detecting addresses and mapping addresses of lighting units  102  to physical locations.  
      Typically, in a two-way communication system the devices on a network can be queried and they respond through the two-way communications network. In this way a list of the devices on the network can be created and stored in the configuration file. However, because data signals and data generators must be robust against faults, noise, breaks and the like, a non-trivial amount of circuitry is required to drive a network in a robust manner for two-way communcications. For networked lighting units  100 , cost is an important factor, so it may not be desirable to have a more expensive two-way communications network. Thus, lighting units  100  or other devices on a network may not contain driver circuitry to provide a two-way communication path, thus keeping them simple and low cost. However, if there is a one-way communication path on a network then devices on a network do not respond, and the identities of these devices are unknown unless discovered or entered a priori. Methods and systems described below allow a system to identify lighting units  100  and other network devices without a two-way communication path.  
      In view of the foregoing, one embodiment of the invention is directed to methods and systems that facilitate a determination of the respective identifiers of controllable lighting units or other network devices coupled together to form a networked system, such as a lighting system. In one aspect of this embodiment, each lighting unit of the system has a pre-programmed multiple-bit binary identifier, and a determination algorithm is implemented to iteratively determine (i.e., “learn”) the identifiers of all lighting units that make up the system. In various aspects, such determination/learning algorithms may employ a variety of detection schemes during the identifier determination process, including, but not limited to, monitoring a power drawn by lighting units at particular points of the process, monitoring an illumination state of one or more lighting units at particular points of the determination process, or monitoring exceptional conditions such as shorts in the data communication path to one or more lighting units.  
      Once the collection of identifiers for all lighting units of the system is determined (or manually entered), another embodiment of the present invention is directed to facilitating the compilation of mapping information that relates the identified lighting units  102  to their relative physical locations in the installation. In various aspects of this embodiment, the mapping information compilation process may be facilitated by one or more graphical user interfaces that enable a system operator and/or programmer to conveniently configure the system based on either learned and/or manually entered identifiers of the lighting units, as well as one or more graphic representations of the physical layout of the lighting units relative to one another.  
      In an embodiment, identifiers for lighting units  102  can be determined by a series of steps. First, a set of lighting units  102  having unique identifiers stored in memory  3700  are provided. Next, address identification information is provided to the lighting units. Next, the lighting unit  102  is caused to read the address identification information, compare the address identification information to at least a portion of the identifier, and cause the lighting unit  102  to respond to the address identification information by either energizing or de-energizing one or more light sources of the lighting unit  102 . Finally, the system monitors the power consumed by the lighting unit to provide an indication of the comparison between the identifier and the address identification information.  
      In embodiments each lighting unit controller includes a power sensing module that provides one or more indications to the LUC when power is being drawn by one or more lighting units coupled to the LUC (i.e., when one or more light sources of one or more of the lighting units is energized). The power-sensing module also may provide one or more output signals to the processor  3600 , and the processor  3600  in turn may communicate to the central control facility  3500  information relating to power sensing.  
      The power sensing module, together with the processor  3600 , may be adapted to determine merely when any power is being consumed by any of the lighting units coupled to the LUC, without necessarily determining the actual power being drawn or the actual number of units drawing power. As discussed further below, such a “binary” determination of power either being consumed or not consumed by the collection of lighting units  102  coupled to the LUC facilitates an identifier determination/learning algorithm (e.g., that may be performed by the LUC processor  3600  or the central control facility  3500 ) according to one embodiment of the invention. In other aspects, the power sensing module and the processor  3600  may be adapted to determine, at least approximately, and actual power drawn by the lighting units at any given time. If the average power consumed by a single lighting unit is known a priori, the number of units consuming power at any given time can then be derived from such an actual power measurement. Such a determination is useful in other embodiments of the invention, as discussed further below.  
      As discussed above, according to one embodiment of the invention, the LUC processor  3600  may monitor the output signal from the power sensing module to determine if any power is being drawn by the group of lighting units, and use this indication in an identifier determination/learning algorithm to determine the collection of identifiers of the group of lighting units coupled to the LUC. For purposes of illustrating the various concepts related to such an algorithm, the following discussion assumes an example of a unique four bit binary identifier for each of the lighting units coupled to a given LUC. It should be appreciated, however, that lighting unit identifiers according to the present invention are not limited to four bits, and that the following example is provided primarily for purposes of illustration.  
       FIG. 38  illustrates a binary search tree  3800  based on four bit identifiers for lighting units, according to one embodiment of the invention. In  FIG. 38 , it is assumed that three lighting unit  102  are coupled to a generic LUC, and that the first lighting unit has a first binary identifier  3802 A of one, one, zero, one (1101), the second lighting unit has a second binary identifier  3802 B of one, one, zero, zero (1100), and the third lighting unit has a third binary identifier  3802 C of one, zero, one, one (1011). Referring to  FIG. 39 , exemplary identifiers are used below to illustrate an example of an identifier determination/learning algorithm depicted in  FIG. 39 .  
      In embodiments, the collection of identifiers corresponding to the respective units and the number of units are determined. However, it should be appreciated that no particular determination is made of which lighting unit has which identifier. Stated differently, the algorithm does not determine a one-to-one correspondence between identifiers and lighting units, but rather merely determines the collection of identifiers of all of the lighting units coupled to the LUC. According to one embodiment of the invention, such a determination is sufficient for purposes of subsequently compiling mapping information regarding the physical locations of the lighting units relative to one another.  
      One or both of a given LUC processor  3600  or the central control facility  3500  may be configured to execute the algorithm, and that either the processor  3600  or the central control facility  3500  may include memory  3700  to store a flag for each bit of the identifier, which flag may be set and reset at various points during the execution of the algorithm, as discussed further below. Furthermore, for purposes of explaining the algorithm, it is to be understood that the “first bit” of an identifier refers to the highest order binary bit of the identifier. In particular, with reference to the example of  FIG. 38 , the four identifier bits are consecutively indicated as a first bit  3804 , a second bit  3808 , a third bit  3810 , and a fourth bit  3812 .  
      Referring again to the exemplary identifiers and binary tree illustrated in  FIG. 38 , the mapping algorithm implements a complete search of the binary tree to determine the identifiers of all lighting units coupled to a given LUC. The algorithm begins by selecting a first state (either a 1 or a 0) for the highest order bit  3804  of the identifier, and then sends a global command to all of the lighting units coupled to the LUC to energize one or more of their light sources if their respective identifiers have a highest order bit corresponding to the selected state. Again for purposes of illustration, it is assumed here that the algorithm initially selects the state “1” (indicated with the reference character  3814  in  FIG. 38 ). In response to this command, all of the lighting units energize their light sources and, hence, power is drawn from the LUC. It should be appreciated, however, that the algorithm may initially select the state “0” (indicated with the reference character  3818  in  FIG. 38 ); in the present case, since no lighting unit has an identifier with a “0” in the highest order bit  3804 , no power would be drawn from the LUC and the algorithm would respond by setting a flag for this bit, changing the state of this bit, and by default assume that all of the lighting units coupled to the LUC necessarily have a “1” in the highest order bit (as is indeed the case for this example).  
      As a result of a “1” in the highest order bit having been identified, the algorithm adds another bit  3808  with the same state (i.e., “1”), and then sends a global command to all of the lighting units to energize their light sources if their respective identifiers begin with “11” (i.e., 11XX). As a result of this query, the first and second lighting units energize their light sources and draw power, but the third lighting unit does not energize. In any event, some power is drawn, so the algorithm then queries if there are any more bits in the identifier. In the present example there are more bits, so the algorithm returns to adding another bit  3810  with the same state as the previous bit and then sends a global command to all lighting units to energize their light sources if their respective identifiers begin with “111” (i.e., 111X).  
      At this point in the example, no identifiers correspond to this query, and hence no power is drawn from the LUC. Accordingly, the algorithm sets a flag for this third bit  3810 , changes the state of the bit (now to a “0”), and again queries if there are any more bits in the identifier. In the present example there are more bits, so the algorithm returns to adding another bit  3812  with the same state as the previous bit (i.e., another “0”) and then sends a global command to all lighting units to energize their light sources if they have the identifier “1100.” 
      In response to this query, the second lighting unit energizes its light sources and hence power is drawn from the LUC. Since there are no more bits in the identifiers, the algorithm has thus learned a first of the three identifiers, namely, the second identifier  3802 B of “1100.” At this point, the algorithm checks to see if a flag for the fourth bit  3812  has been set. Since no flag yet has been set for this bit, the algorithm changes the bit state (now to a “1”), and sends a global command to all lighting units to energize their light sources if they have the identifier “1101.” In the present example, the first lighting unit energizes its light sources and draws power, indicating that yet another identifier has been learned by the algorithm, namely, the first identifier  3802 A of “1101.” 
      At this point, the algorithm goes back one bit in the identifier (in the present example, this is the third bit  3810 ) and checks to see if a flag was set for this bit. As pointed out above, indeed the flag for the third bit was set (i.e., no identifiers corresponded to “111X”). The algorithm then checks to see if it has arrived back at the first (highest order) bit  3804  again, and if not, goes back yet another bit (to the second bit  3808 ). Since no flag has yet been set for this bit (it is currently a “1”), the algorithm changes the state of the second bit (i.e., to a “0” in the present example), and sends a global command to all lighting units to energize their light sources if their respective identifiers begin with “10” (i.e., 10XX). In the current example, the third lighting unit energizes its light sources, and hence power is drawn. Accordingly, the algorithm then sets the flag for this second bit, clears any lower order flags that may have been previously set (e.g., for the third or fourth bits  3810  and  3812 ), and returns to adding another bit  3810  with the same state as the previous bit. From this point, the algorithm executes as described above until ultimately it learns the identifier  1402 C of the third lighting unit (i.e., 1011), and determines that no other lighting units are coupled to the LUC.  
      Again, it should be appreciated that although an example of four bit identifiers was used for purposes of illustration, the algorithm may be applied similarly to determine identifiers having an arbitrary number of bits. Furthermore, it should be appreciated that this is merely one example of an identifier determination/learning algorithm, and that other methods for determining/learning identifiers may be implemented according to other embodiments of the invention.  
      In this method, the central controller,  3500 , determines either that (i) no devices respond or (ii) at least one device on the network responds.  
      The algorithmic sequence is a mask and value sequence that with algorithmic methods can rapidly determine the identifiers of all of the network devices. The queries continue to guide and refine the search, and the queries themselves become more complex as the tree of possibilities is traversed. As an example the query might be expressed in English as “Do you have a 1 in the first position, a 0 in the second position and a 1 in the third position?” 
      If no device satisfies the query, then all identifiers further down the search tree are pruned from the search. If one or more devices satisfy the query then the search moves on to other bits to determine the unique identifier. This is an efficient binary search technique. After a rapid sequence of steps, the complete set of identifiers for all of the networked devices can be established. However, it should be appreciated that other methods of search can be employed including the exhaustive, sequential or breadth first or depth first search techniques.  
      Once the identification of the network devices is complete, the unique identifiers can be used to communicate directly with those devices or a separate address can be established that is more befitting the networking protocol. For example, in one embodiment the unique identifier may be represented by 32 bits but the address, such as that for DMX protocol, may be only 8 bits. Thus once the unique identifiers are determined, another communication sequence can be established to create or change the address of the network device.  
      In another aspect to the invention, the backchannel technique can be used to read data stored in the memory of the network device. This may include parameters for calibration, testing, temperature and other values that can be stored on the device. In one aspect of the invention the data can be read out of EEPROM.  
      In another embodiment of this system, this system can be integrated into a load center or circuit breaker box. Using the power draw technique for bit indication, then devices on the power network can indicate their unique identifier. This assumes one-way communication to the device, which can be over the power lines or by RF or optical or electromagnetic means.  
      Once the identification of the individual devices on the network is completed, another technique can be used to identify topology of the network, namely, timing. In this embodiment a single remote networked device is commanded to drive the data line to HIGH or LOW. This provides a shorted path for electrical testing and timing. In this embodiment an electrical signal is sent over the line and timed for a return to the central controller. Using this technique and accurate timing, the position on the network, and importantly, the relative position on the network can be determined. This knowledge of relative positions of the individual devices assists with the mapping of the various devices on the network and their relative positions for later control purposes. It should be appreciated that there are a variety of means to establish the distance of a short along a wire and that this particular technique in no way limits the type of technique used.  
      In networks where the nodes on a serial network have no unique identifier but can be individually controlled, another technique is used to determine the number of nodes on a string. In this system, the addresses are implicit from the position on the string. In this invention the number of nodes in the system can be determined by monitoring power draw. It is assumed that there are a maximum number of nodes on a string such as 256 nodes. Each node is individually addressable but we do not know how many nodes are on the string. The combination of binary search and power monitoring is used to determine the number of nodes on the string. At each step a single node is tested and the outcome determines whether to check above or below that node. In one embodiment a binary search provides the answer.  
      A command to one node whose number equals half of the maximum number of devices is sent to the node network. If power is consumed then the last node number must be above that node number and a value half-way between the old value and the max value is tested. If no power is consumed then it must be a lower number and then next node number chosen is one-half of the previous value. This binary sequence continues and the number of nodes on the string can be precisely determine in N steps where 2ˆN is the number of nodes.  
      For example if there are 256 maximum possible nodes but a given string has only 83 then the test, in one scenario, can be constructed as:  
      Test node  128 . No power. Check lower.  
      Test node  64 . Power consumed. Check higher.  
      Test node (128−64/2=96) No power. Check lower.  
      Test node  80 . Power consumed. Check higher  
      Test node  88 . No power consumed. Check lower  
      Test node  84 , No power consumed. Check lower  
      Test node  82 . Power consumed. Check higher  
      Test node  83  Power consumed. Check higher.  
      83 is the number of nodes since 84 was tested without power consumption. In this example eight total steps allows determination of the exact number of nodes.  
      Another embodiment of the invention is to monitor power increments and count up the string until there is no more increase in power draw.  
      In another embodiment of the invention, rather than using a power-sensing module, a central controller can act by forcing the data on the line to either extreme to ‘low’ or to ‘high’. For example, a controller can drive the base of a transistor and thus bring the data line to ground. In another embodiment, the central device determines that the data line has been forced high or low, through a voltage divider and thus the sequence of command and response provides one bit of information: a ‘yes’ or ‘no’ indication that, for example, there is a device on the network that has or hasn&#39;t a 1 in that position. In this embodiment, this becomes a binary search, identical to that described above for the power-sensing module. In one embodiment the data line is pulled low by using a signal from the controller in the network device connected to the base of a transistor that connects the data line to ground.  
      In embodiments the binary search trees described herein may vary based on the types of lighting units for which positions are sought. As described above, with linear strings of lighting units, a binary search is done, turning on specific lights and measuring the current draw of the string to determine if there is a real, illuminated light at the chosen address. The search is narrowed down in a binary divide-and-conquer manner until it is evident what the address of the last light on the string is. A string, though, is always linear. With other embodiments, such as the arrays  2208  described in connection with  FIG. 22 , there can be two or more boards  204  with arrays  2208  chained together on the same power/data supply output. It is desirable to detect not just how many nodes are attached to the power/data supply, but also how many boards  204  and how many nodes or lighting units  100  per board  204 . In embodiments a board  204  can have an extra node on the board  204 , one that draws current but has no LED attached. The nodes responds to, but does not interfere with, the data that is sent to the last node on a board  204 . The power/data supply linearly searches the attached nodes and can detect when no more nodes are attached by noting that no current is drawn at the address in question, while it can also detect when it has lit up the last node on a board when the current drawn is twice what would ordinarily be expected (from both the real and the extra node responding at the address in question).  
      These methods create a communication backchannel that is highly asymmetric to the forward channel. Unlike DMX, when using a linear addressing protocol there is not one transmitter and many listeners. Instead, there is one transmitter (the power/data supply) and one listener (the first processor  3600  in the string). This first processor  3600  is then the transmitter on a different electrical connection to the second processor  3600 , which is a receiver, and so on. In embodiments it is not possible to transmit in the reverse direction down the chain. So, the communications backchannel, as used for the binary tree search methods described herein, is implemented through the power wires, by measuring the presence or absence of load, or the difference between two loads; or the magnitude of any of the above. In embodiments just one single bit of information (is this or is this not the last node?) is conveyed, but there is no limit to what kinds of information may be transmitted through this unconventional backchannel.  
      Referring to  FIG. 40 , in another embodiment, the lighting unit controller may not include a power monitoring system but the methodology of identifying lighting unit addresses according to the principles of the present invention may still be achieved. For example, rather than monitoring the power consumed by one or more lighting units, a visible interpretation of the individual lighting units may be recorded, either by human intervention or another image capture system such as a camera or video recorder. In this case, the images of the light emitted by the individual lighting units may be recorded for each bit identification and it may not be necessary to go up and down the binary task tree as identified above.  
      The method may involve the controlling of light from a plurality of lighting units that are capable of being supplied with addresses (identifiers). The method may comprise the steps of equipping each of the lighting units with a processing facility for reading data and providing instructions to the lighting units to control at least one of the color and the intensity of the lighting units, each processing facility capable of being supplied with an address. For example, the lighting units may include a lighting unit  102  where the processor  3600  is capable of receiving network data. The processor may receive network data and operate the LED(s)  300  in a manner consistent with the received data. The processor may read data that is explicitly or implicitly addressed to it or it may respond to all of the data supplied to it. The network commands may be specifically targeting a particular lighting unit with an address or group of lighting units with similar addresses or the network data may be communicated to all network devices. A communication to all network devices may not be addressed but may be a universe or world style command.  
      The method may further comprise the step of supplying each processor with an identifier, the identifier being formed of a plurality of bits of data. For example, each lighting unit  102  may be associated with memory  3700  (e.g. EPROM) and the memory  3700  may contain a serial number that is unique to the light or processor. Of course, the setting of the serial number or other identifier may be set through mechanical switches or other devices and the present invention is not limited by a particular method of setting the identifier. The serial number may be a 32-bit number in EPROM for example.  
      The method may also comprise sending to a plurality of such processors an instruction, the instruction being associated with a selected and numbered bit of the plurality of bits of the identifier, the instruction causing the processor to select between an “on” state of illumination and an “off” state of illumination for light sources controlled by that processor, the selection being determined by the comparison between the instruction and the bit of the identifier corresponding to the number of the numbered bit of the instruction. For example, a network command may be sent to one or more lighting units in the network of lighting units. The command may be a global command such that all lighting units that receive the command respond. The network command may instruct the processors  102  to read the first bit of data associated with its serial number. The processor  3600  may then compare the first bit to the instructions in the network instruction or assess if the bit is a one or a zero. If the bit is a one, the processor may turn the lighting unit on or to a particular color or intensity. This provides a visual representation of the first bit of the serial number. A person or apparatus viewing the light would understand that the first bit in the serial number is either a one (e.g. light is on) or a zero (e.g. light is off). The next instruction sent to the light may be to read and indicate the setting of the second bit of the address. This process can be followed for each bit of the address allowing a person or apparatus to decipher the address by watching the light sources of the lighting unit turn on and/or off following each command.  
      After reducing ambient light at a step  4002 , a camera may capture at a step  4006  a representation of which lights are turned on at a step  4004 . The method may further comprise capturing a representation of which lighting units are illuminated and which lighting units are not illuminated for that instruction. For example, a camera, video or other image capture system may be used to capture the image of the lighting unit(s) following each such network command. Repeating the preceding two steps for all numbered bits of the identifier allows for the reconstruction of the serial number of each lighting unit in the network at an analysis step  4008 . At a step  4012  the analysis is used to generate a table of mapping data for lighting units  102 .  
      The method may further comprise assembling the identifier for each of the lighting units, based on the “on” or “off” state of each bit of the identifier as captured in the representation. For example, a person could view the lighting unit&#39;s states and record them to decipher the lighting unit&#39;s serial number or software can be written to allow the automatic reading of the images and the reassembly of the serial numbers from the images. The software may be used to compare the state of the lighting unit with the instruction to calculate the bit state of the address and then proceed to the next image to calculate the next bit state. The software may be adapted to calculate a plurality or all of the bit states of the associated lighting units in the image and then proceed to the next image to calculate the next bit state. This process could be used to calculate all of the serial numbers of the lighting units in the image.  
      The method may also comprise assembling a correspondence between the known identifiers (e.g. serial numbers) and the physical locations of the lighting units having the identifiers. For example, the captured image not only contains lighting unit state information but it also contains lighting unit position information. The positioning may be relative or absolute. For example, the lighting units may be mounted on the outside of a building and the image may show a particular lighting unit is below the third window from the right on the seventy second floor. This lighting unit&#39;s position may also be referenced to other lighting unit positions such that a map can be constructed which identifies all of the identifiers (e.g. serial numbers) with a lighting unit and its position. Once these positions and/or lighting units are identified, network commands can be directed to the particular lighting units by addressing the commands with the identifier and having the lighting unit respond to data that is addressed to its identifier. The method may further comprise controlling the illumination from the lighting units by sending instructions to the desired lighting units at desired physical locations. Another embodiment may involve sending the now identified lighting units address information such that the lighting units store the address information as its address and will respond to data sent to the address. This method may be useful when it is desired to address the lighting units in some sequential scheme in relation to the physical layout of the lighting units. For example, the user may want to have the addresses sequentially increase as the lighting fixtures go from left to right across the face of a building. This may make authoring of lighting sequences easier because the addresses are associated with position or progression.  
      Another aspect of the present invention relates to communicating with lighting units and altering their address information. In an embodiment, a lighting unit controller LUC may be associated with several lighting units and the controller may know the address information/identifiers for the lighting units associated with the controller. A user may want to know the relative position of one lighting unit as compared to another and may communicate with the controller to energize a lighting unit such that the user can identify its position within an installation. For example, the user may use a computer with a display to show representations of the controller and the lighting units associated with the controller. The user may select the controller, using the representation on the display, and cause all of the associated lighting units to energize allowing the user to identify their relative or absolute positions. A user may also elect to select a lighting unit address or representation associated with the controller to identify its particular position with the array of other lighting units. The user may repeat this process for all the associated lighting unit addresses to find their relative positions. Then, the user may rearrange the lighting unit representations on the display in an order that is more convenient (e.g. in order of the lighting units actual relative positions such as left to right). Information relating to the rearrangement may then be used to facilitate future communications with the lighting units. For example, the information may be communicated to the controller and the lighting units to generate new ‘working’ addresses for the lighting units that correspond with the re-arrangement. In another embodiment, the information may be stored in a configuration file to facilitate the proper communication to the lighting units.  
      In embodiments a method of determining/compiling mapping information relating to the physical locations of lighting units is provided that includes steps of providing a display system; providing a representation of a first and second lighting unit wherein the representations are associated with a first address; providing a user interface wherein a user can select a lighting unit and cause the selected lighting units to energize; selecting a lighting unit to identify its position and repeating this step for the other lighting unit; re-arranging the representations of the first lighting unit and the second lighting unit on the display using a user interface; and communicating information to the lighting units relating to the rearrangement to set new system addresses. The method may include other steps such as storing information relating to the re-arrangement of the representations on a storage medium. The storage medium may be any electronic storage medium such as a hard drive; CD; DVD; portable memory system or other memory device. The method may also include the step of storing the address information in a lighting unit as the lighting unit working address.  
      In various embodiments, once the lighting units have been identified, the lighting unit controller may transmit the address information to a computer system. The computer system may include a display (e.g., a graphics user interface) where a representation of the lighting unit controller is displayed as an object. The display may also provide representations of the lighting unit  102  as an object. In an embodiment, the computer, possibly through a user interface, may be used to re-arrange the order of the lighting unit representations. For example, a user may click on the lighting unit representation and all of the lighting units associated with the lighting unit controller may energize to provide the user with a physical interpretation of the placement of the lighting unit (e.g. they are located on above the window on the 72 nd  floor of the building). Then, the user may click on individual lighting unit representations to identify the physical location of the lighting unit within the array of lighting units. As the user identifies the lighting unit locations, the user may rearrange the lighting unit representations on the computer screen such that they represent the ordering in the physical layout. In an embodiment; this information may be stored to a storage medium. The information may also be used in a configuration file such that future communications with the lighting units are directed per the configuration file. In an embodiment, information relating to the rearrangement may be transmitted to the lighting unit controller and new ‘working’ addresses may be assigned to the individual lighting units. This may be useful in providing a known configuration of lighting unit addresses to make the authoring of lighting shows and effects easier.  
      Another aspect of the present invention relates to systems and methods of communicating to large-scale networks of lighting units. In an embodiment, the communication to the lighting units originates from a central controller where information is communicated in high level commands to lighting unit controllers. The high level commands are then interpreted by the lighting unit controllers, and the lighting unit controllers generate lighting unit commands. In an embodiment, the lighting unit controller may include its own address such that commands can be directed to the associated lighting units through controller-addressed information. For example, the central controller may communicate light controller addressed information that contains instructions for a particular lighting effect. The lighting unit controller may monitor a network for its own address and once heard, read the associated information. The information may direct the lighting unit controller to generate a dynamic lighting effect (e.g. a moving rainbow of colors) and then communicate control signals to its associated lighting units to effectuate the lighting effect. In an embodiment, the lighting unit controller may also include group address information. For example, it may include a universe address that associates the controller with other controllers or systems to create a universe of controllers that can be addressed as a group; or it may include a broadcast address such that broadcast commands can be sent to all controllers on the network.  
      Referring to  FIG. 41 , a flow diagram  3900  includes steps for a mapping facility  5002 . A mapping facility  5002  can first discover what interfaces are located on an associated network, such as Ethernet switches or power-data systems. The mapping facility can then discover what lights are present. The mapping facility then creates a map layout, using the addresses and locations identified for lights as described above. The mapping can be a two-dimensional representation of the lighting units  102  associated with the mapping facility  5002 . The mapping facility  5002  allows the user to group lights within the mapping, until a mapping is complete.  
      The light system manager  5000  may operate in part on the authoring computer  5010 , which may include a mapping facility  5002 . The mapping facility  5002  may include a graphical user interface  4212 , or management tool, which may assist a user in mapping lighting units to locations. The management tool may include various panes, graphs or tables, each displayed in a window of the management tool. A lights/interfaces pane lists lighting units or lighting unit interfaces that are capable of being managed by the management tool. Interfaces may include power/data supplies (PDS)  1758  for one or more lighting systems, DMX interfaces, DALI interfaces, interfaces for individual lighting units, interfaces for a tile lighting unit, or other suitable interfaces. The interface also includes a groups pane, which lists groups of lighting units that are associated with the management tool, including groups that can be associated with the interfaces selected in the lights/interfaces pane. As described in more detail below, the user can group lighting units into a wide variety of different types of groups, and each group formed by the user can be stored and listed in the groups pane. The interface also includes the layout pane, which includes a layout of individual lighting units for a light system or interface that is selected in the lights/interfaces pane. The layout pane shows a representative geometry of the lighting units associated with the selected interface, such as a rectangular array if the interface is an interface for a rectangular tile light. The layout can be any other configuration, as described in connection with the other figures above. Using the interface  4212 , a user can discover lighting systems or interfaces for lighting systems, map the layout of lighting units associated with the lighting system, and create groups of lighting units within the mapping, to facilitate authoring of shows or effects across groups of lights, rather than just individual lights. The grouping of lighting units dramatically simplifies the authoring of complex shows for certain configurations of lighting units.  
      Referring to  FIG. 42 , the graphical user interface  4212  of the mapping facility  5002  of the authoring computer  5010  can display a map, or it may represent a two- or three-dimensional space in another way, such as with a coordinate system, such as Cartesian, polar or spherical coordinates. In embodiments, lights in an array, such as a rectangular array, can be represented as elements in a matrix, such as with the lower left corner being represented as the origin (0, 0) and each other light being represented as a coordinate pair (x, y), with x being the number of positions away from the origin in the horizontal direction and y being the number of positions away from the origin in the vertical direction. Thus, the coordinate (3, 4) can indicate a light system three positions away from the origin in the horizontal direction and four positions away from the origin in the vertical direction. Using such a coordinate mapping, it is possible to map addresses of real world lighting systems into a virtual environment, where control signals can be generated and associated geometrically with the lighting systems. With conventional addressable lighting systems, a Cartesian coordinate system may allow for mapping of light system locations to authoring systems for light shows. In other embodiments, three-dimensional representations can be provided to simulate three-dimensional locations of lights in the real world, and object-oriented techniques allow manipulation of the representations in the graphical user interface  4212  to be converted to lighting control signals that reflect what is occurring in the graphical user interface  4212 .  
      It may be convenient to map lighting systems in various ways. For example, a rectangular array can be formed by suitably arranging a curvilinear string of lighting units. The string of lighting units may use a serial addressing protocol, such as described in the applications incorporated by reference herein, wherein each lighting unit in the string reads, for example, the last unaltered byte of data in a data stream and alters that byte so that the next lighting unit will read the next byte of data. If the number of lighting units N in a rectangular array of lighting units is known, along with the number of rows in which the lighting units are disposed, then, using a table or similar facility, a conversion can be made from a serial arrangement of lighting units  1  to N to another coordinate system, such as a Cartesian coordinate system. Thus, control signals can be mapped from one system to the other system. Similarly, effects and shows generated for particular configurations can be mapped to new configurations, such as any configurations that can be created by arranging a string of lighting units, whether the share is rectangular, square, circular, triangular, or has some other geometry. In embodiments, once a coordinate transformation is known for setting out a particular geometry of lights, such as building a two-dimensional geometry with a curvilinear string of lighting units, the transformation can be stored as a table or similar facility in connection with the light management system  5002 , so that shows authored using one authoring facility can be converted into shows suitable for that particular geometric arrangement of lighting units using the light management system  5002 . The light system composer  5004  can store pre-arranged effects that are suitable for known geometries, such as a color chasing rainbow moving across a tile light with sixteen lighting units in a four-by-four array, a burst effect moving outward from the center of an eight-by-eight array of lighting units, or many others.  
      Various other geometrical configurations of lighting units are so widely used as to benefit from the storing of pre-authored coordinate transformations, shows and effects. For example, a rectangular configuration is widely employed in architectural lighting environments, such as to light the perimeter of a rectangular item, such as a space, a room, a hallway, a stage, a table, an elevator, an aisle, a ceiling, a wall, an exterior wall, a sign, a billboard, a machine, a vending machine, a gaming machine, a display, a video screen, a swimming pool, a spa, a walkway, a sidewalk, a track, a roadway, a door, a tile, an item of furniture, a box, a housing, a fence, a railing, a deck, or any other rectangular item. Similarly, a triangular configuration can be created, using a curvilinear string of lighting units, or by placing individual addressable lighting units in the configuration. Again, once the locations of lighting units and the dimensions of the triangle are known, a transformation can be made from one coordinate system to another, and pre-arranged effects and shows can be stored for triangular configurations of any selected number of lighting units. Triangular configurations can be used in many environments, such as for lighting triangular faces or items, such as architectural features, alcoves, tiles, ceilings, floors, doors, appliances, boxes, works of art, or any other triangular items.  
      Lighting units  102  can be placed in the form of a character, number, symbol, logo, design mark, trademark, icon, or other configuration designed to convey information or meaning. The lighting units can be strung in a curvilinear string to achieve any configuration in any dimension. Again, once the locations of the lighting units are known, a conversion can be made between Cartesian (x, y) coordinates and the positions of the lighting units in the string, so that an effect generated using a one coordinate system can be transformed into an effect for the other. Characters such as those mentioned above can be used in signs, on vending machines, on gaming machines, on billboards, on transportation platforms, on buses, on airplanes, on ships, on boats, on automobiles, in theatres, in restaurants, or in any other environment where a user wishes to convey information.  
      Lighting units can be configured in any arbitrary geometry, not limited to two-dimensional configurations. For example, a string of lighting units can cover two sides of a building. The three-dimensional coordinates (x, y, z) can be converted based on the positions of the individual lighting units in the string. Once a conversion is known between the (x, y, z) coordinates and the string positions of the lighting units, shows authored in Cartesian coordinates, such as for individually addressable lighting units, can be converted to shows for a string of lighting units, or vice versa. Pre-stored shows and effects can be authored for any geometry, whether it is a string or a two- or three-dimensional shape. These include rectangles, squares, triangles, geometric solids, spheres, pyramids, tetrahedrons, polyhedrons, cylinders, boxes and many others, including shapes found in nature, such as those of trees, bushes, hills, or other features.  
      Referring to  FIG. 41 , a flow diagram  3900  shows various steps that are optionally accomplished using the mapping facility  5002 , such as the interface  4212 , to map lighting units and interfaces for an environment into maps and layouts on the authoring computer  5010 . At a step  3902 , the mapping facility  1652  can discover interfaces for lighting systems, such as power/data supplies  1758 , tile light interfaces, DMX or DALI interfaces, or other lighting system interfaces, such as those connected by an Ethernet switch. At a step  3904  a user determines whether to add more interfaces, returning to the step  3902  until all interfaces are discovered. At a step  3908  the user can discover a lighting unit, such as one connected by Ethernet, or one connected to an interface discovered at the step  3902 . The lights can be added to the map of lighting units associated with each mapped interface, such as in the lights/interfaces pane of the interface  4212 . At a step  3910  the user can determine whether to add more lights, returning to the step  3908  until all lights are discovered. When all interfaces and lights are discovered, the user can map the interfaces and lights, such as using the layout pane of the interface  4212 . Standard maps can appear for tiles, strings, arrays, or similar configurations. Once all lights are mapped to locations in the layout pane, a user can create groups of lights at a step  3918 , returning from the decision point  3920  to the step  3918  until the user has created all desired groups. The groups appear in the groups pane as they are created. The order of the steps in the flow diagram  3900  can be changed; that is, interfaces and lights can be discovered, maps created, or groups formed, in various orders. Once all interfaces and lights are discovered, maps created and groups formed, the mapping is complete at a step  3922 . Many embodiments of a graphical user interface for mapping lights in a software program may be envisioned by one of skill in the art in accordance with this invention.  
      Using a mapping facility, light systems can optionally be mapped into separate zones, such as DMX zones. The zones can be separate DMX zones, including zones located in different rooms of a building. The zones can be located in the same location within an environment. In embodiments the environment can be a stage lighting environment.  
      Thus, in various embodiments, the mapping facility allows a user to provide a grouping facility for grouping light systems, wherein grouped light systems respond as a group to control signals. In embodiments the grouping facility comprises a directed graph. In embodiments, the grouping facility comprises a drag and drop user interface. In embodiments, the grouping facility comprises a dragging line interface. The grouping facility can permit grouping of any selected geometry, such as a two-dimensional representation of a three-dimensional space. In embodiments, the grouping facility can permit grouping as a two-dimensional representation that is mapped to light systems in a three-dimensional space. In embodiments, the grouping facility groups lights into groups of a predetermined conventional configuration, such as a rectangular, two-dimensional array, a square, a curvilinear configuration, a line, an oval, an oval-shaped array, a circle, a circular array, a square, a triangle, a triangular array, a serial configuration, a helix, or a double helix.  
      Referring to  FIG. 42 , a light system composer  5004  can be provided, running on the authoring computer  5010 , for authoring lighting shows comprised of various lighting effects. The lighting shows can be downloaded to the light system engine  5008 , to be executed on lighting units  102 . The light system composer  5004  is preferably provided with a graphical user interface  4212 , with which a lighting show developer interacts to develop a lighting show for a plurality of lighting units  102  that are mapped to locations through the mapping facility  5002 . The user interface  4212  supports the convenient generation of lighting effects, embodying the object-oriented programming approaches described above.  
      Referring to  FIG. 43 , the user interface  4212  allows a user to develop shows and effects for associated lighting units  102 . The user can select an existing effect by initiating a tab  4052  to highlight that effect. In embodiments, certain standard attributes are associated with all or most effects. Each of those attributes can be represented by a field in the user interface  4050 . For example, a name field  4054  can hold the name of the effect, which can be selected by the user. A type field  4058  allows the user to enter a type of effect, which may be a custom type of effect programmed by the user, or may be selected from a set of preprogrammed effect types, such as by clicking on a pull-down menu to choose among effects. For example, in  FIG. 43 , the type field  4058  for the second listed effect indicates that the selected effect is a color-chasing rainbow. A group field  4060  indicates the group to which a given effect is assigned, such as a group created through the light system manager interface  2550  described above. For example, the group might be the first row of a tile light, or it might be a string of lights disposed in an environment. A priority field  4062  indicate the priority of the effect, so that different effects can be ranked in their priority. For example, an effect can be given a lower priority, so that if there are conflicting effects for a given group during a given show, the a higher priority effect takes precedence. A start field  4064  allows the user to indicate the starting time for an effect, such as in relation to the starting point of a lighting show. An end field  4068  allows the user to indicate the ending time for the effect, either in relation to the timing of the lighting show or in relation to the timing of the start of the effect. A fade in field  4070  allows the user to create a period during which an effect fades in, rather than changes abruptly. A fade out field  4072  allows the user to fade the effect out, rather than ending it abruptly. For a given selected type of effect, the parameters of the effect can be set in an effects pane  4074 . The effects pane  4074  automatically changes, prompting the user to enter data that sets the appropriate parameters for the particular type of effect. A timing pane  4078  allows the user to set timing of an effect, such as relative to the start of a show or relative to the start or end of another effect. Parameters can exist for all or most effects. These include the name  4152 , the type  4154 , the group  4158 , the priority  4160 , the start time  4162 , the end time  4164 , the fade in parameter  4168  and the fade out parameter  4170 .  
      Referring to  FIG. 44 , a set of effects can be linked temporally, rather than being set at fixed times relative to the beginning of a show. For example, a second effect can be linked to the ending of a first effect at a point  4452 . Similarly, a third effect might be set to begin at a time that is offset by a fixed amount relative to the beginning of the second effect. With linked timing of effects, a particular effect can be changed, without requiring extensive editing of all of the related effects in a lighting show. Once a series of effects is created, each of them can be linked, and the group can be saved together as a meta effect, which can be executed across one or more groups of lights. Once a user has created meta effects, the user can link them, such as by linking a first meta effect and a second meta effect in time relative to each other. Linking effects and meta effects, a user can script entire shows, or portions of shows. The creation of reusable meta effects can greatly simplify the coding of shows across groups.  
      In embodiments a user can select an animation effect, in which a user can generate an effect using software used to generate a dynamic image, such as Flash  5  computer software offered by Macromedia, Incorporated. Flash  5  is a widely used computer program to generate graphics, images and animations. Other useful products used to generate images include, for example, Adobe Illustrator, Adobe Photoshop, and Adobe LiveMotion.  
      Referring to  FIG. 45 , a flow diagram  4500  shows steps for converting computer animation data to lighting control signals. In a light management facility  5000 , a map file  4504  is created. A graphics facility  4508  is used to create an animation, which is a sequence  4510  of graphics files. A conversion module  4512  converts the map file and the animation facility, based on linking pixels in the animation facility to lights in the mapping facility. The playback tool  4514  delivers data to light systems  4518 , so that the light systems  100  play lighting shows that correspond to the animation effects generated by the animation facility.  
      Various effects can be created, such as a fractal effect, a random color effect, a sparkle effect, streak effect, sweep effect, white fade effect, XY burst effect, XY spiral effect, and text effect.  
      As seen in connection with the various embodiments of the user interface  4212  and related figures, methods and systems are included herein for providing a light system composer  5004  for allowing a user to author a lighting show using a graphical user interface  4212 . The light system composer  5004  includes an effect authoring system for allowing a user to generate a graphical representation of a lighting effect. In embodiments the user can set parameters for a plurality of predefined types of lighting effects, create user-defined effects, link effects to other effects, set timing parameters for effects, generate meta effects, and generate shows comprised of more than one meta effect, including shows that link meta effects.  
      In embodiments, a user may assign an effect to a group of light systems. Many effects can be generated, such as a color chasing rainbow, a cross fade effect, a custom rainbow, a fixed color effect, an animation effect, a fractal effect, a random color effect, a sparkle effect, a streak effect, an X burst effect, an XY spiral effect, and a sweep effect. In embodiments the light system composer  5004  allows the user to generate a scrolling effect, such as one that moves across a regular or irregular array of light sources  300 , such as a group of boards  204  with arrays  2208  such as described in connection with  FIGS. 22   a - d . The scrolling effect may be a graphic, a logo, an animation effect, a scrolling text effect, an alphanumeric effect, or other scrolling effect.  
      In embodiments an effect can be an animation effect. In embodiments the animation effect corresponds to an animation generated by an animation facility. In embodiments the effect is loaded from an animation file. The animation facility can be a flash facility, a multimedia facility, a graphics generator, or a three-dimensional animation facility.  
      In embodiments the lighting show composer facilitates the creation of meta effects that comprise a plurality of linked effects. In embodiments the lighting show composer generates an XML file containing a lighting show according to a document type definition for an XML parser for a light engine. In embodiments the lighting show composer includes stored effects that are designed to run on a predetermined configuration of lighting systems. In embodiments the user can apply a stored effect to a configuration of lighting systems. In embodiments the light system composer includes a graphical simulation of a lighting effect on a lighting configuration. In embodiments the simulation reflects a parameter set by a user for an effect. In embodiments the light show composer allows synchronization of effects between different groups of lighting systems that are grouped using the grouping facility. In embodiments the lighting show composer includes a wizard for adding a predetermined configuration of light systems to a group and for generating effects that are suitable for the predetermined configuration. In embodiments the configuration is a rectangular array, a string, or another predetermined configuration.  
      Once a show is downloaded to the light system engine  5008 , the light system engine  5008  can execute one or more shows in response to a wide variety of user input. For example, a stored show can be triggered for a lighting unit  102  that is mapped to a particular PDS  1758  associated with a light system engine  5008 . There can be a user interface for triggering shows downloaded on the light system engine  5008 . For example, the user interface may be a keypad, with one or more buttons for triggering shows. Each button might trigger a different show, or a given sequence of buttons might trigger a particular show, so that a simple push-button interface can trigger many different shows, depending on the sequence. In embodiments, the light system engine  5008  might be associated with a stage lighting system, so that a lighting operator can trigger pre-scripted lighting shows during a concert or other performance by pushing the button at a predetermined point in the performance.  
      In embodiments, other user interfaces can trigger shows stored on a light system engine  5008 , such as a knob, a dial, a button, a touch screen, a serial keypad, a slide mechanism, a switch, a sliding switch, a switch/slide combination, a sensor, a decibel meter, an inclinometer, a thermometer, a anemometer, a barometer, or any other input capable of providing a signal to the light system engine  5008 . In embodiments the user interface is the serial keypad, wherein initiating a button on the keypad initiates a show in at least one zone of a lighting system governed by a light system engine connected to the keypad.  
      Referring to  FIG. 46 , a flow diagram  4600  indicates steps for object-oriented authoring of lighting shows as associated with other computer programs, such as computer games, three-dimensional simulations, entertainment programs and the like. First, at a step  4602  it is possible to code an object in an application. At a step  4604  it is possible to create instances for the objects. At a step  4608  light a system can add light as an instance to the object in the program. At the step  4610  the system can add a thread to the code of the object-oriented program. At a step  4612  the system can draw an input signal from the thread of the object-oriented program for delivering control signals to a light system  100 . By adding light as an instance, lighting control signals can go hand-in-hand with other objects, instances and events that take place in other object-oriented computer programs.  
      Referring to  FIG. 47 , a light system composer  5004  can be used to generate an effect that has various parameters. The parameters include the name  4752 , type  4754 , group  4758 , priority  4760 , start time  4762 , end time  4764 , fade in  4768  and fade out  4770 , as well as other parameters for particular effects.  
       FIG. 2  also illustrates that the lighting unit  102  may be configured to receive one or more signals  122  from one or more other signal sources  8400 . In one implementation, the processor  3600  of the lighting unit may use the signal(s), either alone or in combination with other control signals (e.g., signals generated by executing a lighting program, one or more outputs from a user interface, etc.), so as to control one or more of the light sources  300  in a manner similar to that discussed above in connection with the user interface  4908 .  
      Examples of the signal(s) that may be received and processed by the processor  3600  include, but are not limited to, one or more audio signals, video signals, power signals, various types of data signals, signals representing information obtained from a network (e.g., the Internet), signals representing some detectable/sensed condition, signals from lighting units, signals consisting of modulated light, etc. In various implementations, the signal source(s)  8400  may be located remotely from the lighting unit  102 , or included as a component of the lighting unit. For example, in one embodiment, a signal from one lighting unit  102  could be sent over a network to another lighting unit  102 .  
      Some examples of a signal source  8400  that may be employed in, or used in connection with, the lighting unit  102  of  FIG. 2  include any of a variety of sensors  8402  or transducers that generate one or more signals in response to some stimulus. Examples of such sensors include, but are not limited to, various types of environmental condition sensors, such as thermally sensitive (e.g., temperature, infrared) sensors, humidity sensors, motion sensors, inclinometers, GPS devices, dead-reckoning devices, gyros, photosensors/light sensors (e.g., sensors that are sensitive to one or more particular spectra of electromagnetic radiation), sound or vibration sensors or other pressure/force transducers (e.g., microphones, piezoelectric devices), and the like.  
      Additional examples of a signal source  8400  include various metering/detection devices that monitor electrical signals or characteristics (e.g., voltage, current, power, resistance, capacitance, inductance, etc.) or chemical/biological characteristics (e.g., acidity, a presence of one or more particular chemical or biological agents, bacteria, etc.) and provide one or more signals based on measured values of the signals or characteristics. Yet other examples of a signal source  8400  include various types of scanners, image recognition systems, voice or other sound recognition systems, artificial intelligence and robotics systems, and the like.  
      A signal source  8400  could also be a lighting unit  102 , a processor  3600 , or any one of many available signal generating devices, such as media players, MP3 players, computers, DVD players, CD players, television signal sources, camera signal sources, microphones, speakers, telephones, cellular phones, instant messenger devices, SMS devices, wireless devices, personal organizer devices, and many others.  
      Many types of signal source  8400  can be used, for sensing any condition or sending any kind of signal, such as temperature, force, electricity, heat flux, voltage, current, magnetic field, pitch, roll, yaw, acceleration, rotational forces, wind, turbulence, flow, pressure, volume, fluid level, optical properties, luminosity, electromagnetic radiation, radio frequency radiation, sound, acoustic levels, decibels, particulate density, smoke, pollutant density, positron emissions, light levels, color, color temperature, color saturation, infrared radiation, x-ray radiation, ultraviolet radiation, visible spectrum radiation, states, logical states, bits, bytes, words, data, symbols, and many others described herein, described in the documents incorporated by reference herein, and known to those of ordinary skill in the arts.  
      In embodiments the lighting unit  102  can include a timing feature based on an astronomical clock, which stores not simply time of day, but also solar time (sunrise, sunset) and can be used to provide other time measurements such as lunar cycles, tidal patterns and other relative time events (harvest season, holidays, hunting season, fiddler crab season, etc.) In embodiments, using a timing facility, a controller  202  can store data relating to such time-based events and make adjustments to control signals based on them. For example, a lighting unit  102  can allow ‘cool’ color temperature in the summer and warm color temperatures in the winter.  
      In embodiments the sensor  8402  can be a light sensor, and the sensor can provide control of a lighting signal based on a feedback loop, in which an algorithm modifies the lighting control signal based on the lighting conditions measured by the sensor. In embodiments, a closed-loop feedback system can read spectral properties and adjust color rendering index, color temperature, color, intensity, or other lighting characteristics based on user inputs or feedback based on additional ambient light sources to correct or change light output.  
      A feedback system, whether closed loop or open loop, can be of particular use in rendering white light. Some LEDs, such as those containing amber, can have significant variation in wavelength and intensity over operating regimes. Some LEDs also deteriorate quickly over time. To compensate for the temperature change, a feedback system can use a sensor to measure the forward voltage of the LEDs, which gives a good indication of the temperature at which the LEDs are running. In embodiments the system could measure forward voltage over a string of LEDs rather than the whole fixture and assume an average value. This could be used to predict running temperature of the LED to within a few percent. Lifetime variation would be taken care of through a predictive curve based on experimental data on performance of the lights. Degradation can be addressed through an LED that produces amber or red through another mechanism such as phosphor conversion and does this through a more stable material, die or process. Consequently, CRI could also improve dramatically. That LED plus a bluish white or Red LED then enables a color temperature variable white source with good CRI.  
      In embodiments a lighting system may coordinate with an external system  8800 , such as to trigger lighting shows or effects in response to events of the external system, to coordinate the lighting system with the other system, or the like. External systems  8800  can include other lighting systems  100 , entertainment systems, security systems, control systems, information technology systems, servers, computers, personal digital assistants, transportation systems, and many other computer-based systems, including control signals for specific commercial or industrial applications, such as machine vision systems, photographic systems, medical systems, pool systems, spa systems, automotive systems, and many others.  
      A lighting system  100  can be used to produce various effects  9200 , including static effects, dynamic effects, meta effects, geometric effects, object-oriented shows and the like. Effects can include illumination effects  9300 , where light from a lighting unit  102  illuminates another object, such as a wall, a diffuser, or other object. Illumination effects  9300  include generating white lighting with color-temperature control. Effects can also include direct view effects  9400 , where light sources  300  are viewed directly or through another material. Direct view effects includes displays, works of art, information effects, and others. Effects can include pixel-like effects, effects that occur along series or strings of lighting units  102 , effects that take place on arrays of lighting units  102 , and three-dimensional effects.  
      In various embodiments of the present invention, the lighting unit  102  shown in  FIG. 2  may be used alone or together with other similar lighting units in a system of lighting units (e.g., as discussed further below in connection with  FIG. 2 ). Used alone or in combination with other lighting units, the lighting unit  102  may be employed in a variety of applications including, but not limited to, interior or exterior space illumination in general, direct or indirect illumination of objects or spaces, theatrical or other entertainment-based/special effects illumination, decorative illumination, safety-oriented illumination, vehicular illumination, illumination of displays and/or merchandise (e.g. for advertising and/or in retail/consumer environments), combined illumination and communication systems, etc., as well as for various indication and informational purposes.  
      Referring to  FIG. 48 , an effect  9200  can include a symbolic effect, such as a sign  1204  disposed on the exterior of a building  4800  or on an interior wall or other object. Such a sign  1204  can be displayed many other places, such as inside a building, on a floor, wall, or ceiling, in a corridor, underwater, submerged in a liquid other than water, or in many other environments. A sign  1204  can consist of a backlit display portion and a configuration, such as of letters, numbers, logos, pictures, or the like. The lighting of the backlit portion and the configuration can be coordinated to provide contrasting colors and various aesthetic effects.  
      Referring to  FIG. 48 , an object  4850  is lit by a lighting system  4850 . In this case the object  4850  is a three-dimensional object. The object  4850  can also be lit internally, to provide its own illumination. Thus, the object  4850  can include color and color temperature of light as a medium, which can interact with changes in color and color temperature from the lighting system  4850 .  FIG. 48  depicts a foreground object  4850  and a background  4852 , both with lighting units  102 . Thus, both the foreground object  4850  and the background  4852  can be illuminated in various colors, intensities or color temperatures. In an embodiment, the illumination of the foreground object  4850  and the background  4852  can be coordinated by a processor  3600 , such as to produce complementary illumination. For example, the colors of the two can be coordinated so that the color of the background  4852  is a complementary color to the color of the foreground object  4850 , so when the background  4852  is red, the foreground object  4850  is green, etc. Any object  4850  in any environment can serve as a foreground object  4850 . For example, it might be an item of goods in a retail environment, an art object in a display environment, an emergency object in a safety environment, a tool in a working environment, or the like. For example, if a processor  3600  is part of a safety system, the object  4850  could be a fire extinguisher, and the background  4852  could be the case that holds the extinguisher, so that the extinguisher is illuminated upon a fire alert to make it maximally noticeable to a user. Similarly, by managing the contrast between the background  4852  and the object  4850 , an operator of a retail environment can call attention to the object  4850  to encourage purchasing.  
      In embodiments linear strings or series of lights can embody time-based effects  4854 , such as to light a lighting unit  102  in a series when a timed-pulse crosses the location of that lighting unit  102 .  
      Effects can be designed to play on arrays  4860 , such as created by strings of lighting units  102  that are arranged in such arrays. Effects can be designed in accordance with target areas  4862  that are lit by lighting units  102 , rather than in accordance with the lighting units  102  themselves.  
      Referring to  FIG. 49 , effects can be tied to a sensor  8402  that detects motion in proximity to a lighting unit  102 . Waving a hand or other object in proximity to the sensor  8402  can trigger shows or effects. Effects can also play out over arrays, such as triangular configurations  9258  and rectangular arrays  9260 . Effects can cause shows to play out over such arrays in a wide range of effects, such as a bounce effect  9260 . In embodiments a lighting system  9250  illuminates an object  9252 . Depending on the color of the object, it may either be highlighted or not based on the color of the illumination. For example, red illumination will highlight a red object, but blue illumination will make the red object appear dark. Systems can produce motion effects  9262  by illuminating in different colors over time, so that different items appear highlighted at different times, such as the wings  9262  of different colors in  FIG. 49 .  
      Referring to  FIG. 50 , in embodiments of the methods and systems provided herein, the lighting systems further include disposing at least one such lighting unit on a building  5050 . In embodiments the lighting units are disposed in an array on a building. In embodiments the array is configured to facilitate displaying at least one of a number, a word, a letter, a logo, a brand, and a symbol. In embodiments the array is configured to display a light show with time-based effects. In other embodiments lighting units may be disposed on interior walls  5052  to produce such effects.  
      Lighting systems  100  can be found in a wide range of environments  9600 . Referring to  FIG. 51 , environments  9600  include airline environments  5102  and other transportation environments, home exterior environments  5108 , such as decks, patios and walkways, seating environments  5104  such as in airline cabins, buses, boats, theatres, movies, auditoriums and other seating environments, building environments  5110 , such as to light a profile of a building, pool and spa environments  5112 , cylindrical lighting environments  5114 , domed lighting environments  5118  and many others. Referring to  FIG. 52 , environments  9600  can include airline cabins  5202 , bus environments  5204 , medical and surgical environments  5208 , dressing room environments  5210 , retail display environments  5212 , cabinet environments  5214 , beauty environments  5218 , work environments  5220 , and under-cabinet environments  5222 . Referring to  FIG. 53 , additional environments  9600  include home entertainment environments  5302 , motion picture and other camera environments  5304 , recreational environments  5308 , such as boating, interior environments  5310 , seating environments  5312 , railings  5318 , stairs  5320  and alcoves  5314 . Referring to  FIG. 54 , environments  9600  can include automobiles  5402 , appliances  5404 , trees and plants  5408 , houses  5410 , playing fields and courts  5412 , display environments  5414 , signage environments  5418 , ceiling tiles  5420 , signaling environments  5422 , marine signaling environments  5424 , theatrical environments  5428  and bowling environments  5430 . Referring to  FIG. 55 , other environments  9600  include swimming environments  5502 , military and aircraft environments  5504 , industrial environments  5508 , such as hangars and warehouses, house environments  5520 , train environments  5512 , automotive environments  5514 , such as undercar lightings, fireplace environments  5518  and landscape environments  5520 .  
      The various concepts discussed herein may be suitably implemented in a variety of environments involving LED-based light sources, other types of light sources not including LEDs, environments that involve both LEDs and other types of light sources in combination, and environments that involve non-lighting-related devices alone or in combination with various types of light sources.  
      The combination of white light with light of other colors as light sources for lighting units  102  can offer multi-purpose lights for many commercial and home applications, such as in pools, spas, automobiles, building interiors (commercial and residential), indirect lighting applications, such as alcove lighting, commercial point of purchase lighting, merchandising, toys, beauty, signage, aviation, marine, medical, submarine, space, military, consumer, under cabinet lighting, office furniture, landscape, residential including kitchen, home theater, bathroom, faucets, dining rooms, decks, garage, home office, household products, family rooms, tomb lighting, museums, photography, art applications, and many others.  
      One environment  9600  is a retail environment. An object might be an item of goods to be sold, such as apparel, accessories, electronics, toys, food, or any other retail item. The lighting units  102  can be controlled to light the object with a desired form of lighting. For example, the right color temperature of white light can render the item in a true color, such as the color that it will appear in daylight. This may be desirable for food items or for apparel items, where color is very significant. In other cases, the lighting units  102  can light the item with a particular color, to draw attention to the items, such as by flashing, by washing the item with a chasing rainbow, or by lighting the item with a distinctive color. In other cases the lighting can indicate data, such as rendering items that are on sale in a particular color, such as green. The lighting can be controlled by a central controller, so that different items are lit in different colors and color temperatures along any timeline selected by the user. Lighting systems can also interact with other computer systems, such as cards or handheld devices of a user. For example, a light can react to a signal from a user&#39;s handheld device, to indicate that the particular user is entitled to a discount on the object that is lit in a particular color when the user is in proximity. The lighting units  102  can be combined with various sensors that produce a signal source  8400 . For example, an object may be lit differently if the system detects proximity of a shopper.  
      Subjects to be displayed under controlled lighting conditions also appear in other environment, such as entertainment environments, museums, galleries, libraries, homes, workplaces, and the like.  
      In a workplace environment lighting units  102  can be used to light the environment  9600 , such as a desk, cubicle, office, workbench, laboratory bench, or similar workplace environment. The lighting systems can provide white and non-white color illumination of various colors, color temperatures, and intensities, so that the systems can be used for conventional illumination as well as for aesthetic, entertainment, or utilitarian effects, such as illuminating workplace objects with preferred illumination conditions, such as for analysis or inspection, presenting light shows or other entertainment effects, or indicating data or status. For example, coupled with a signal source  8400 , such as a sensor, the workplace lighting systems could illuminate in a given color or intensity to indicate a data condition, such as speed of a factory line, size of a stock portfolio, outside temperature, presence of a person in an office, whether someone is available to meet, or the like.  
      In embodiments, lighting systems can include an architectural lighting system, an entertainment lighting system, a restaurant lighting system, a stage lighting system, a theatrical lighting system, a concert lighting system, an arena lighting system, a signage system, a building exterior lighting system, a landscape lighting system, a pool lighting system, a spa lighting system, a transportation lighting system, a marine lighting system, a military lighting system, a stadium lighting system, a motion picture lighting system, photography lighting system, a medical lighting system, a residential lighting system, a studio lighting system, and a television lighting system.  
      In embodiments of the methods and systems provided herein, the lighting systems can be disposed on a vehicle, an automobile, a boat, a mast, a sail, an airplane, a wing, a fountain, a waterfall or similar item. In other embodiments, lighting units can be disposed on a deck, a stairway, a door, a window, a roofline, a gazebo, a jungle gym, a swing set, a slide, a tree house, a club house, a garage, a shed, a pool, a spa, furniture, an umbrella, a counter, a cabinet, a pond, a walkway, a tree, a fence, a light pole, a statue or other object.  
      Referring to  FIG. 56 , in embodiments a housing  800  for a lighting unit  100  may include a retrofit housing  5602 . The retrofit housing  5602  may be configured to fit a conventional lighting fixture, such as a fluorescent lighting fixture. The retrofit housing  5602  is shaped to fit over the space where a conventional fluorescent bulb is located, with the light sources  300  disposed on the top of the retrofit housing to replace the fluorescent bulb as the light source for the fluorescent lighting fixture. A screw hole  5604  or clip can be used to help fasten the unit  100  to a platform, such as a lighting fixture or a flat surface.  
      Referring to  FIG. 57 , another retrofit unit  5702  is designed to fit over the part of a fluorescent lighting fixture where the bulbs are located, so that the light sources  300  replace the fluorescent bulb. Screw holes  5702  or clips can be used to fasten the unit  5702  to a surface, such as the surface of a fixture.  
      Referring to  FIG. 58 , a housing  800  forms a cylindrical retrofit unit  5802 , with a board  204  and light sources  300  disposed on the board  204 . The housing  5802  is designed to fit over a conventional circular or cylindrical fixture. A metal tab  5804  serves as a mechanical connector for the housing  5802  and serves as a thermal facility  2500 , providing a heat conduction path from the board  204  and light sources  300  the lighting fixture to which the housing  5802  can be attached. A screw hole  5808  or clip of the tab  5804  can be used to attach the unit  5802  to a surface.  
       FIG. 59  shows a retrofit unit  5902  with two rows of light sources  300  to provide light. The retrofit unit  5902  is designed to fit over the space where a fluorescent bulb would otherwise fit. The unit  5902  also provides a thermal conduction path as a thermal facility  2500  to transmit heat from the light sources  300  to the fixture to which the retrofit unit  5902  is attached. The unit  5902  includes tabs  5908  with screw holes  5904  or clips to attach the unit  5902  to a surface, such as a fluorescent lighting fixture.  
       FIG. 60  shows a retrofit housing  5702  viewed from below. The light sources  300  may be connected to one or more processors  3600 , which may provide control to the light sources  300  that are disposed on the top of the retrofit housing  5702 .  
      Referring to  FIG. 61 , a retrofit housing  5602  can fit over a ballast  6108  of a fluorescent fixture. A cable  6102  can be strung through a hole  6104  in the fluorescent fixture to provide power and data to the light sources  300  of the housing  5602 .  
      Referring to  FIG. 62 , a retrofit housing  5702  with light sources  300  is configured to fit over the ballast  6208  of a fluorescent fixture. A cable  6202  can be strung through a hole  6204  to deliver power and data to the light sources  300 .  
      Referring to  FIG. 63 , a hanging lighting fixture  6308  includes a substantially linear channel  6310 , into which fluorescent tubes are normally placed. The fixture includes a diffuser  6304  that diffuses light from the light sources  300  that are disposed on retrofit boards  6302  that are disposed in the linear channel  6310 .  
      Referring to  FIG. 64 , a down light unit  6402  includes light sources  300  as a replacement for a conventional linear bulb, such as a fluorescent or compact fluorescent bulb. The light sources  300  can be positioned on boards  204  both at the top  6404  and underneath the unit  6402 , so that the light sources  300  shine both up toward, for example, a ceiling and down, such as toward the diffuser  6408 . The unit  6404  can be designed to retrofit onto any of a wide range of lighting fixtures, such as to replace fluorescent tubes that are used to light such fixtures.  
      Referring to  FIG. 65 , a flat fixture  6502  includes lines of light sources  300 , as well as an on-board power/data supply  6304  for delivering power and data to the light sources  300 . Cables  6508  can run through a space  6510  on the platform  6512 , such as to allow wiring of the fixture  6502  onto a surface.  
      Referring to  FIG. 66 , a retrofit fixture  6602  is designed to fit over a conventional lighting socket, such as a socket for an incandescent or halogen lamp. The retrofit fixture  6602  includes a substantially circular board  204  onto which the light sources  300  are disposed. The fixture  6602  includes sides  6604  that extend downward around the socket  6612 . Flared tabs  6610  include screw holes  6608  to allow the user to screw the fixture  6602  over the socket  6612 . The sides  6604  may be made of a thermally conductive material to serve as a thermal facility  2500 , such as to conduct heat away from the light sources  300  to the fixture to which the retrofit fixture  6602  is attached.  
       FIG. 67  depicts a fixture  6702  in which light sources  300  are disposed substantially in lines along two planes that are substantially perpendicular to each other. The fixture  6702  can fit over any surface that includes a corner, such as a corner of a wall, a ceiling, a floor, a rectangular fixture, or the like.  
       FIG. 68  shows a linear lighting fixture  6808  with pins  6814  for supplying power and data to the light sources  300 . Power/data supplies  6802 ,  6804  and cables  6810 ,  6812  provide power and data to the ends of the fixture  6808 . The power/data supplies  6802 ,  6804  can be disposed with the board  204 , or on a lighting fixture to which the unit  6802  is attached. The power/data supplies  6802 ,  6804  can power one or more light sources  300 . In embodiments the power/data supplies  6802 ,  6804  may be designed to accommodate power from a power line or from a power supply for a traditional lighting fixture, such as a ballast for a fluorescent fixture.  
       FIG. 69  shows a linear lighting unit  6902  where an on-board power/data supply  6904  supplies power and data to one end of the lighting fixture  6902 . The power/data supply  6904  can be disposed with the board  204 , or on a lighting fixture to which the unit  6902  is attached. The power/data supply  6902  can power one or more light sources  300 . In embodiments the power/data supply  6902  may be designed to accommodate power from a power line or from a power supply for a traditional lighting fixture, such as a ballast for a fluorescent fixture.  
       FIG. 70  shows a lighting unit  100  with light sources  300  disposed on a board  204 . The board may be a printed circuit board or similar circuit board  204 . The board may be positioned on top of a heat-conducting plate  7004 , such as a metal plate, that acts as a thermal facility  2500  for conducting heat away from the light sources  300 . The heat conducting plate  7004  can conduct heat from the light sources  300  to a flared, heat conductive structure  7002  that serves as a further thermal facility  2500 , conducting heat from the board  204  and metal plate  7004  to the fixture housing  800 , such as when the board  204  is pressed downward so that the sides of the board  204  contact the flared structure  7002 . The unit  100  may include a power/data supply  7008 , such as an on-board power/data supply  7008  for supplying power and data for one or more light sources  300 . In embodiments the power/data supply  7008  may be attached to the fixture or may be a remote power/data supply.  
       FIG. 71  shows a lighting unit  100  with a cylindrical optical facility  400 , such as a transparent lens  7102  that includes a board  204  with light sources  300 . The lens  7102  serves as a protective cover for the light sources  300 , prevents a person from touching the light sources  300  and electronics elements (which in embodiments may be high-voltage circuit elements), protects the electronics elements from environmental conditions, and shields the light sources  300  from heat coming from the environment of the lighting unit  100 . A conductive plate  7104  serves as a heat sink thermal facility  2500  for conducting heat away from the board  204  and light sources  300 . The heat sinking plate  7104  can cool radiantly in the air, or it can connect, for example, to a housing for a lighting fixture into which the unit is disposed.  
       FIG. 72  shows a lighting unit  100  formed into a retrofit housing  7302  with three sides. Two opposite sides  7204 ,  7208  are substantially parallel, and both are attached to a top side  7210  that is perpendicular to both. A processor  3600 , such as an ASIC, can be positioned on the back each of the sides  7204 ,  7208 ,  7210  and associated with each grouping of light sources  300 . The housing  7302  can be designed to fit over a traditional lighting unit, such as a linear lighting fixture, such as a fluorescent fixture, to replace the fluorescent bulb as the light source in the fixture.  
      Referring to  FIG. 73 , an array  2208  of light sources  300  may be covered with a cover  7302  that includes optical facilities  400 , such as lenses for shaping beams of light coming from the light sources  300 . The cover  7302  may be attached by fasteners  7304 , such as screws.  
      Referring to  FIG. 74 , in embodiments the boards  204  that hold the arrays  2208  may be fitted with magnetic facilities  7402  along the sides for fastening one board  204  to another. The magnetic facilities  7402  may provide a magnetic connection, as well as providing a power and/or data interface between the boards. The boards  204  may be fitted with other fastening facilities for connecting one board  204  to another, such as ball/socket combinations, adhesives, tapes, interlocking shapes, tabs, or the like. In one embodiment are disclosed solderable finger joints. Such features, in one embodiment, allow for tile mapping or discovery means during assembly by choice of solder pad for interconnection. The choice of an electrical path provides an indication of an identifying means to provide different inputs to onboard controllers through input and output pins within the modules.  
      In embodiments the arrays  2208  may be irregular arrays of nodes of light sources  300 , as can the boards  204  that hold the arrays  2208 .  
      Referring to  FIG. 75 , in embodiments the arrays  2208  may be disposed on boards  204  that have interlocking edge joints  7502 ,  7504 , so that one board  204  fits into another board  204 . The boards  204  can have dedicated in/out pads  7502 ,  7504  for data that allow for mapping during assembly by selecting a pad to which a solder will be performed. The interlocking boards can be in different planes, such as to form a right angle. In embodiments interlocking boards  204  can be combined to create geometric shapes, such as the tessellated shapes described elsewhere herein. Such shapes, in combination with narrow beam angle light sources  300  allow a lighting unit  100  to project an image onto multiple surfaces simultaneously.  
       FIG. 76  shows another embodiment of interlocking boards  204 , with tab  7604  designed to fit into space  7602  to form a physical connection, and in embodiments allowing a data and/or power connection.  
      Referring to  FIG. 77 , in embodiments the boards  204  that hold the arrays  2208  can include sensors, such as for sensing yaw, pitch, and roll relative to a mapping or geometric position, to assist in mapping the direction of light from the light sources  300 . In embodiments the cover  2212  may provide a sealed cover, such as to allow underwater use. Sensors may include GPS, inclinometers, gyros, inertial navigation sensors, dead reckoning devices and other motion sensors.  
      Referring to  FIG. 78 , the arrays  2208  can be provided with snap-in interchangeable lenses  7802 , such as to change the light coming from the light sources  300 .  
      Referring to  FIG. 79 , a lighting unit  100  may be disposed in or on a block  7902 , such as a block of glass, plastic, or the like. The block  7902  can be used as a structure material, such as to build larger light systems.  
      Referring to  FIG. 80 , a lighting unit  100  with light sources  300  may be constructed using a flexible circuit board material  8050  on which a processor  3600  is also disposed to provide control for the light sources  300 .  
      Referring to  FIG. 81 , an array  2208  can be attached to a wall with a mounting cleat  8102 , which may be disposed in proximity to a power/data supply  8104  for supplying power and data to the lighting unit  100 . The cleat-style mounting can have an integrated electrical connection as well as power. The small ridges, shown in profile in  FIG. 81 , provide electrical connection for both power and data. In another embodiment a feature is provided for attachment to an electrical junction box. In one embodiment the ridges are be shaped horizontally. In another embodiment the ridges are be horizontal features.  
      In embodiments the boards  204  may include a thermally conductive gap pad or similar thermal facility  2500  to hold heat away from the light sources  300 . In embodiments the cover  2212  may provide a sealed housing. The housing may then be an oil-filled housing with clear oil to serve as a thermal facility  2500  and an optical facility  400 . A non-conductive particulate could make the light more diffuse. In embodiments the board  204  may include a snap-on secondary optical facility  400  to guide light coming from the light sources  300 .  
      In embodiments the boards  204  may include integrated power/data rails for rapid installation. The rails can be provided in a grid format so that boards  204  can snap into the grid for rapid assembly. In embodiments the rails may serve as tracks, providing a system similar to track lighting where boards  204  snap into a track.  
      In embodiments a board  204  or other lighting unit  100  may be caused to provide live feedback during installation. The lighting unit  100  can blink or display a specific color in relation to reaching a maximum number of unit per power supply for power or data. The lighting units  100  can display all units in a particular map reason. The lighting units  100  can display particular colors based on geometric orientation, such as measured by a sensor.  
      Having thus described several illustrative embodiments, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of this disclosure. While some examples presented herein involve specific combinations of functions or structural elements, it should be understood that those functions and elements may be combined in other ways according to the present invention to accomplish the same or different objectives. In particular, acts, elements, and features discussed in connection with one embodiment are not intended to be excluded from similar or other roles in other embodiments. Accordingly, the foregoing description and attached drawings are by way of example only, and are not intended to be limiting.