Abstract:
Various methods and apparatus report energy usage status by a networked device. In response to a request, a set of power usage data is retrieved from a non-volatile memory located within the networked device, the power usage data having been previously stored in the non-volatile memory in advance of positioning the networked device for normal use. The set of power usage data includes information related to energy usage of the networked device. The networked device calculates a best estimate of the energy usage status of the networked device based on the set of power usage data retrieved from the non-volatile memory, without measuring electrical parameters of a power source of the networked device during normal use. The best estimate of the energy usage status by the networked device is then sent over the network as a reply to the energy usage status request.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Prov. Appl. No. 61/254,709 entitled “HYBRID LIGHT” filed on Oct. 25, 2009, and U.S. Prov. App. No. 61/261,707 entitled “AUTOMATED LOAD ASSESSMENT DEVICE” filed Nov. 16, 2009, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present subject matter relates to home automation networking. It further relates to the monitoring and reporting by networked devices of their power or energy usage. 
     2. Description of Related Art 
     Providing home automation functionality using networking means is well known in the art. Control of lighting and appliances can be accomplished using systems from many different companies such as X10, Insteon® and Echelon. 
     In U.S. Pat. No. 6,528,954, inventors Lys and Mueller describe a smart light bulb which may include a housing, an illumination source, disposed in the housing, and a processor, disposed in the housing, for controlling the illumination source. The housing may be configured to fit a conventional light fixture. The illumination source may be an LED system or other illumination source. The processor may control the intensity or the color of the illumination source. The housing may also house a transmitter and/or receiver. The smart light bulb may respond to a signal from another device or send a signal to another device. The other device may be another smart light bulb or another device. They go on to describe a modular LED unit which may be designed to be either a “smart” or “dumb” unit. A smart unit, in one embodiment, includes a microprocessor incorporated therein for controlling, for example, a desired illumination effect produced by the LEDs. The smart units may communicate with one another and/or with a master controller by way of a network formed through the mechanism for electrical connection described above. It should be appreciated that a smart unit can operate in a stand-alone mode, and, if necessary, one smart unit may act as a master controller for other modular LED units. A dumb unit, on the other hand, does not include a microprocessor and cannot communicate with other LED units. As a result, a dumb unit cannot operate in a stand-alone mode and requires a separate master controller. The smart light bulb may be associated with a wide variety of illumination applications and environments. 
     Ducharme et al., in U.S. Pat. No. 7,014,336, describe systems and methods for generating and/or modulating illumination conditions to generate high-quality light of a desired and controllable color, for creating lighting fixtures for producing light in desirable and reproducible colors, and for modifying the color temperature or color shade of light within a prespecified range after a lighting fixture is constructed. In one embodiment, LED lighting units capable of generating light of a range of colors are used to provide light or supplement ambient light to afford lighting conditions suitable for a wide range of applications. They go on to describe a networked lighting system. U.S. Pat. No. 7,651,245 invented by Thomas, et al., shows an LED light fixture with internal power supply. They describe some embodiments where a radio frequency control unit can receive commands from a centralized controller, such as that provided by a local network, or from another control module positioned in a fixture in close proximity. Thus, the range of the lighting network could be extended via the relaying and/or repeating of control commands between control units. 
     Neither Lys and Mueller, Ducharme et al. nor Thomas, et al. discuss monitoring or reporting the power consumed in their smart light bulb. 
     Inventors Chemel et al. show a method and system for designing improved intelligent, LED-based lighting systems. The LED based lighting systems may include fixtures with one or more of rotatable LED light bars, integrated sensors, onboard intelligence to receive signals from the LED light bars and control the LED light bars, and a mesh network connectivity to other fixtures. In at least one embodiment, light fixtures or associated control systems may measure the electricity they&#39;ve consumed, and report it back to a utility for billing purposes. In another embodiment, the operator user interface may be adapted to provide an operator of the environment with tools for visualizing the energy consumed by at least one of the lighting systems. 
     The system described by Chemel et al. requires expensive sensors to measure the electricity that has been consumed. Measuring the energy consumed and reporting it to the user or home owner is becoming more important over time as more and more people want to make their lifestyle more “green” and carefully monitor and control their energy usage. At the same time, home automation is becoming more prevalent and easier to use. Devices enabled for home automation include control and communication means allowing the devices to include more functionality. So it is becoming very important to enable devices to report their own energy usage as accurately as possible while adding as little cost as possible to individual devices or to the home in general. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute part of the specification, illustrate various embodiments of the invention. Together with the general description, the drawings serve to explain the principles of the invention. In the drawings: 
         FIG. 1  shows a stylized view of a home with a plurality of networked home automation devices; 
         FIG. 2  shows a block diagram view of a network of home automation devices; 
         FIGS. 3A and 3B  show a networked light bulb; 
         FIG. 4  shows a block diagram of the electronics utilized in one embodiment of the networked light bulb; 
         FIGS. 5A and 5B  are flowcharts of the how a log of device operating conditions may be maintained; 
         FIG. 6  shows a flowchart of how a networked device may estimate energy usage status; 
         FIG. 7  shows a block diagram view of a network of home automation devices that can report and display their energy usage; and 
         FIG. 8  shows a block diagram of a networked device that actually measures energy usage instead of estimating it. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures and components have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present concepts. A number of descriptive terms and phrases are used in describing the various embodiments of this disclosure. These descriptive terms and phrases are used to convey a generally agreed upon meaning to those skilled in the art unless a different definition is given in this specification. Some descriptive terms and phrases are presented in the following paragraphs for clarity. 
     The term “LED” refers to a diode that emits light, whether visible, ultraviolet, or infrared, and whether coherent or incoherent. The term as used herein includes incoherent polymer-encased semiconductor devices marketed as “LEDs”, whether of the conventional or super-radiant variety. The term as used herein also includes semiconductor laser diodes and diodes that are not polymer-encased. It also includes LEDs that include a phosphor or nanocrystals to change their spectral output. 
     The term “energy usage status” refers to any parameter that could be useful in determining the energy used by a networked device. Specifically included in the definition are the instantaneous power used by the networked device at the current or any previous point of time, and the energy used by the networked device over an explicit or implicit period of time. 
     The term “network” refers to a bidirectional communication medium and protocol to allow a plurality of devices to communicate with each other. 
     The term “networked device” refers to any device that can communicate over a network. 
     The terms “networked light fixture”, “networked lighting apparatus” and “networked light bulb” all refer to a networked device capable of emitting light. While there are subtle differences in the generally agreed upon embodiments for these terms, they may be used interchangeably in this disclosure unless additional detail is provided to indicate that a specific embodiment is being discussed. 
     Reference now is made in detail to the examples illustrated in the accompanying drawings and discussed below. 
       FIG. 1  shows a stylized view of a home  100  with a plurality of home networked devices  111 - 127 . In the embodiment shown, the networked devices communicate over a wireless mesh network such as Z-wave or Zigbee (IEEE 802.15.4). Other wireless networks such as Wi-Fi (IEEE 802.11) might be used in a different embodiment. In other embodiments, a power line network such as X10 or HomePlug. In additional embodiments, a wired network could be used such as Ethernet (IEEE 802.3). In other embodiments, an optical network might be employed and some embodiments may utilize a heterogeneous network with multiple types of networks. This exemplary home has five rooms. The kitchen  101  has a networked light fixture  111 , a networked coffee maker  121  and a networked refrigerator  123 . The bedroom  102  has a networked light fixture  112 , and a networked clock radio  122 . The hallway  103  has a networked light bulb  113 . The home office  104  has a networked light fixture  114 , a network controller  120 , and a home computer  140  connected to a network gateway  124 . The living room  105  has two networked light fixtures  115 ,  116  and a networked television  125 . External to the home is a networked floodlight  117  and a networked electric meter  126 . Homeowner  106  is returning to her home with a networked remote control  127  and decides to turn on a networked floodlight  117  to light her way. 
       FIG. 2  shows a block diagram view of the automated home  100  showing only those devices involved with this particular instance of turning on the networked floodlight  117 . The network  130  in this embodiment is a wireless mesh network meaning that individual devices can communicate with each other and that messages may be passed between intermediate devices to be able to reach its intended destination. In some cases, a message may be passed to a central network controller for processing but in other cases, a message may pass from an initiating device directly to a target device without involving the network controller. In the particular instance where the homeowner  106  presses a button  127   u  on the remote control  127 , a controller  127   c  within the remote control  127  interprets the button press and creates a network message describing the task being requested. In this embodiment, the network message needs to be routed through the network controller  120  so the message created by the remote control controller  127   c  sets that up as the target of the message and passes the message to the network adapter  127   n  of the remote control  127 . The network adapter  127   n  is unable to send the message directly to the network controller  120  so it sends a radio frequency network message  131  to the nearest networked device that is within range, is currently powered on, and has the capability to route the message  131  to another networked device to get it to the network controller  120 . In this case, the coffee maker  121  happens to be off and the refrigerator  123  does not happen to have routing capability, so the radio frequency message  131  is accepted by the network adapter  111   n  of networked light fixture  111 . The controller  111   n  in the networked light fixture  111  determines that the message  131  is not intended to turn on its LEDs  111   b  and it needs to be routed to the network controller  120  but the networked light fixture  111  and the network controller  120  are not able to directly communicate due to distance or interference so the controller  111   c  uses network adapter  111   n  to pass the message  131  to networked light bulb  113  as radio frequency message  132 . The network adapter  113   n  and controller  113   c  determine that the message is not meant to turn on the LEDs  113   b  in the networked light bulb  113 , and it is able to directly communicate with the network controller  120 , so the controller  113   c  uses the network adapter  113   n  to send a radio frequency message  133  to the network controller  120 . 
     The network adapter  120   n  of the network controller  120  accepts the message  133  and passes it to the controller  120   c . It then interprets the command which may have multiple functions to perform such as adjusting the temperature of the home, disarming an alarm or other functions that are not specified here. But one function that is required is to turn on floodlight  117 . So the controller  120   c  creates a message telling the floodlight  117  to turn on and has the network adapter  120   n  send it to the light fixture  116  because the floodlight  117  is out of range of the network controller  120 . So the message  134  is passed to the light fixture  116  using its network adapter  116   n  and controller  116   c  and without turning on its light  116   b . The light fixture  116  is within communication range of the floodlight  117  so it sends the message  135  to the floodlight  117 . The network adapter  117   n  receives the message and passes it to the controller  117   c  which interprets the message and turns on the light  117   b  so that the homeowner  106  can find her way to the door. 
       FIG. 3A  shows a front view (with inner structure not shown) and  FIG. 3B  shows a side view (with selected inner structure shown in broken lines) of a networked light bulb  300 . In this embodiment a networked light bulb  300  is shown but other embodiments of the present subject matter could be a permanently installed light fixture with a socket for a standard light bulb, or a light fixture with embedded LEDs or any other sort of light emitting apparatus. It is also representative of any other type of networked device such as the networked coffee maker  121 , the networked refrigerator  123 , the networked clock radio  122 , the networked television  125  or any other type of device that may participate in a home automation network. The light bulb  300  is AC powered but other embodiments could be battery powered or solar powered. The networked light bulb  300  of this embodiment has a base with a power contact  301  and a neutral contact  302 , a middle housing  303  and an outer bulb  304 . Each section  301 ,  302 ,  303 ,  304  can be made of a single piece of material or be assembled from multiple component pieces. The outer bulb  304  is at least partially transparent and may have ventilation openings in some embodiments, but the other sections  301 ,  302 ,  303  can be any color or transparency and be made from any suitable material. The middle housing  303  has an indentation  305  with a slot  306  and an aperture  307 . A color wheel  221  is attached to the shaft of rotary switch  206  which is mounted on a printed circuit board  207 . The printed circuit board  207  with the color wheel  221  is mounted horizontally so that the edge  202  of the color wheel protrudes through the slot  306  of the middle housing  303 . This allows the user to apply a rotational force to the color wheel  221 . As the color wheel  221  rotates, different sections of the colored area of the color wheel  221  are visible through an aperture  307 . In  FIG. 3 , the current position of the color wheel  221  is such the color section with color  4  is visible through the aperture  307 , indicating that the user has selected color  4  at this time. The color selection mechanism  428  may be designed to provide a detent at each section of the colored area to make it clear what color is currently selected. 
     In this embodiment, a second printed circuit board  310  is mounted vertically in the base of the networked light bulb  300 . A board-to-board connection  311  is provided to connect selected electrical signals between the two printed circuit boards  207 ,  310 . A third printed circuit board  314  has a plurality of LEDs  313  mounted on it and is backed by a heat sink  315  to cool the plurality of LEDs  313 . In some embodiments the third printed circuit board  314  with a plurality of LEDs  313  may be replaced by a single multi-die LED package or a single high output LED. In some embodiments the heat sink  315  may not be needed or could be a completely different configuration than what is shown. A cable  312  connects the printed circuit board  207  with the third printed circuit board  314 . The cable  312  carries the power for the plurality of LEDs  313 . In some embodiments it may be connect the second printed circuit board  310  directly to the third printed circuit board  314  instead of passing the signals through the printed circuit board  207 . 
       FIG. 4  shows a block diagram of the control electronics  400  used in the networked light bulb  300 . While the following discussion directed primarily at the embodiment of a networked light bulb  300  the same principles and concepts can be applied by one skilled in the art to any other networked device. The block diagram is divided into three sections  410 ,  420 ,  430  corresponding to the three printed circuit boards of  FIG. 3 . Other embodiments may partition the system differently and have more or fewer printed circuit boards or circuit elements. The three sections are the LED Driver section  410 , corresponding to the second printed circuit board  310 , the networked controller section  420 , corresponding to the printed circuit board  207 , and the LED section  430 , corresponding to the third printed circuit board  314 , The base with contacts  301 ,  302  provides AC power to the AC to DC rectifier  411  to power the LED driver  412 . The LED driver may be an integrated circuit such as the NXP SSL2101 or similar parts from Texas Instruments or others. Several signals are shared in common between the LED driver section  410  and the networked controller section  420  through a board-to-board connection  311 . The board-to-board connection  311  may be a pin and socket connector system, an edge finger connector system, soldered right angle pins, a cable, or any other method of connecting two boards. The shared signals comprise a ground connection, the LED power signal  441 , a regulated power voltage  442 , a control signal  443  and a serial communication signal  444 . In some embodiments, the regulated power voltage  442  may be sufficient to power all the electronics in the networked controller section  420 . In other embodiments, where more power is needed, a DC to DC converter may be included in the networked controller section  420  running off the LED power signal  441 . The ground signal and the LED power signal  441  are then sent from the networked controller section  420  to the LED section  430  over cable  312 . The LED section  430  may have a plurality of LEDs  313  powered by the LED power signal  441 . The LED driver section  410  and LED section  430  could correspond to other sections that transform and consume electrical power or perform operations of a different embodiment of a networked device  300 , such as the heating element of a networked coffee maker  121 , under the control of the networked controller section  420 . 
     The networked controller section  420  would be very similar in any embodiment of a networked device. It has a wireless network adapter  422  that receives radio frequency signals through antenna  425  and is connected to controller  421  by a digital bus  423 . In some embodiments, the wireless network adapter  422  may connect to a Z-wave, Zigbee (IEEE 802.15.4) or Wi-Fi (IEEE 802.11) wireless network. Other embodiments may use a wired or power line network adapter instead of a wireless network adapter. In some embodiments, the controller  421  is implemented as a microcontroller and in some embodiments, the controller  421 , wireless network adapter  422 , and digital bus  423  may be integrated onto a single chip  424  such as the Zensys ZM3102. In some embodiments a timer or clock function is included in the networked controller  420 . The timer or clock function could be implemented as a separate chip, a hardware block within the controller  421 , a firmware function within the controller  421 , or any other way of implementing a timer or clock function. A user interface such as a color selection mechanism  428  may also be connected to the controller  421  providing rotational position information through an electrical connection  426 . In other embodiments a user interface may be provided using other means such as a graphical user interface on a display or a keypad or buttons or any other device or combination of devices that allows the user to make a selection and provide information on the selection to the controller  421 . A non-volatile memory  426  also may be included in the networked controller section  420 . The non-volatile memory  426  can be a flash memory, an EPROM, a battery-backed up RAM, a hard drive, or any other sort of memory device that retains its contents through a power cycle. The non-volatile memory  426  can be implemented as a single integrated circuit, a set of integrated circuits, a block of memory cells integrated with another function such as the controller  421  or the wireless network adapter  422  or any other implementation. The non-volatile memory  426  is connected to the controller through a digital connection  427 . The digital connection could be an I2C bus, an SPI bus, a parallel connection, an internal bus within an integrated circuit, or any other electrical connections means, using a standard or proprietary protocol. 
     The non-volatile memory  426  can contain any number of different data depending on the embodiment including program instructions for the controller  421 , configuration information for the networked device, temporary data for the program running on the controller  421 , a log of different operating conditions of the networked device over time, networking settings or any other digital information useful in a specific embodiment. Some embodiments have a set of power usage data stored in the non-volatile memory  426 . The set of power usage data has at least one data point indicating the amount of power used by the networked device such as the networked light bulb  300 . In some embodiments, the set of power usage data has multiple data points of the power used corresponding to different operating conditions of the networked device. In some embodiments, the operating condition parameters are explicitly stored with the power data points. In other embodiments, the operating condition associated with each data point is implicitly understood by the controller  421  so only a set of power data points is stored. In one embodiment, the different operating conditions of the networked light bulb  300  are different brightness levels of the LEDs  313 . In one embodiment, the brightness levels are explicitly stored with the power level as paired data points such as (25, 1.3), (50, 2.0), (75, 2.5), (100, 2.8) indicating that the networked light bulb  300  uses 1.3 W of power when the LEDs  313  are set to a 25% brightness level, 2.0 W of power when the LEDs  313  are set to a 50% brightness level, 2.5 W when the LEDs  313  are set to a 75% brightness level and 2.8 W when the LEDs are set to a 100% brightness level. In another embodiment, the set of power usage data for the networked light bulb  300  is simply a set of 11 data points such as (0.02, 0.7, 1.0, 1.4, 1.8, 2.0, 2.2, 2.4, 2.6, 2.7, 2.8) corresponding to the power used by the networked light bulb  300  at “Standby” (Dark), 10%, 20%, 30%, 40%, 50%, 60%, 70% 80%, 90% and 100% brightness, the brightness levels understood implicitly by the controller. In other embodiments, the set of power usage has two data points such as (0.02, 2.8) corresponding to a standby power usage and a full power usage. And in at least one other embodiment, only a single power usage data point is stored to represent the best overall estimate of power used whenever the device is in use. 
     In some embodiments, the set of power usage data is determined based on design data, qualification test data, data from the LED supplier, life testing, best guess by an engineer or some other method that does not involve measuring the power used by the particular networked device in question. In some embodiments, the data is calculated and then used for each and every instantiation of that particular design built. In other embodiments, each individual networked device is tested and power usage data collected for one or more operating conditions at the time of manufacturing, final product test, final packaging or sometime before it is sold to the end customer, and that measured data from that individual device is used to create the set of power usage data that is stored in the non-volatile memory  426  of the individual networked device. 
     In some embodiments, the controller  421  controls the brightness of the plurality of LEDs  313  by driving the control signal  443  back to the LED driver  412 . In one embodiment the controller  421  may simply drive the control signal  443  low to turn the plurality of LEDs  313  on and drive the control signal  443  high to turn the plurality of LEDs  313  off. In other embodiments, the controller  421  may drive the control signal  443  with a pulse-width modulated signal to control the brightness of the plurality of LEDS  313 . In some embodiments, the LED driver section  410  is designed to accept power that has been controlled by a standard thyristor-based light dimmer which varies the phase where the AC power is active. This can interact with the dimming control taking place over the network. To determine the current dimming level of the LEDs  313 , the networked controller section  420  may, in some embodiments, include circuitry to monitor the LED power signal  441  to determine the amount of dimming taking place. In other embodiments, the controller  421  may communicate with the LED driver  412  over the serial communications signal  444  to query and perhaps override the current dimming level. The serial communication signal  444  may also be used to communicate the current operating condition of the networked device, actual measured power used if the additional circuitry to measure power is included in the networked device, color temperature control, device temperature information or any other status or control information that might need to be communicated between the controller  421  and the LED driver  412  in a particular embodiment. The serial communication signal  444  may be implemented with a unidirectional or a bidirectional communication protocol such as RS-232, I2C, USB, SPI or any other standard or proprietary protocol. 
       FIGS. 5A and 5B  show flow charts  500 ,  510  for different embodiments of creating a log of operating conditions in the networked device. Other methods may also be used in other embodiments. In one embodiment  500  the controller  421  detects if the networked device undergoes a change  501  of current operating condition. A change of operating condition could be turning on, turning off (standby), changing volume, changing a fan speed, changing the heating level of a heating element, changing the brightness level, or any other change in the condition of the networking device that could impact the amount of power it uses. If a change of state is detected, the controller  421  gets  502  the current time from the timer operating as a function in the controller or in another device. The time does not need to be highly accurate or even set to a real world clock time; it just needs to allow relative values of the time to be compared to get an elapsed time convertible to hours. The controller  421  must then ascertain  503  the current operating condition of the networked device. In some embodiments, the controller  421  always knows the operating condition because it is controlling the operating condition. In other embodiment, the controller  421  must query other devices in the networked device, such as the LED driver  412 , to ascertain the current operating condition. Once the current operating condition and time have been collected, a data point identifying the current operating condition and the time are stored  504  in a data structure in memory. The controller  421  then waits  505  for the next change of operating condition. 
     The flow chart  510  of  FIG. 5B  shows an alternative embodiment of creating a log of operating conditions. In the flow chart  510 , a clock tick is generated at regular intervals and detected  511  by the controller  421 . The clock tick can be generated using the same sort of means as the timer of the first embodiment discussed. For each clock tick, the current operating condition is ascertained  513  as described above and a data point describing the current operating condition is stored  514  into a data structure. With this method, the time is implicitly known based on the clock tick. The time between clock ticks may vary depending on the type of device, the accuracy required of the power estimation, how often the power usage will be queried, and the embodiment, but one clock tick every 10 minutes might be used in one embodiment. The controller  421  then waits  515  for the next clock tick. 
     The memory used for the data structure of the log of operating conditions may be a separate location in the same non-volatile memory  426  that holds the set of power usage data or in some embodiments, it may be a different memory device, volatile of non-volatile. The data structure may be a circular queue of fixed size determined at the time the instructions for the controller are created. In some embodiments, the data structure may be dynamic in size depending on the way the networking device is used. In some embodiments, the data structure may be a linked list or a table. It is clear to one skilled in the art that a log of operating conditions cannot be of infinite size due to storage limitations, so tradeoffs must be made in the design of a particular embodiment. In the case where a data point is created every 10 minutes as in the embodiment described above and where an 8 bit byte can sufficiently describe the operating condition, such as a brightness level at 0.5% granularity or less, a data structure of 256 bytes can hold a log containing over 42 hours of data before some data is lost. That would be adequate for an embodiment where it is expected that all devices will be queried by a centralized power management console at least once each day. 
       FIG. 6  shows a flow chart  600  for calculating a best estimate of the energy usage status based on the set of power usage data stored in non-volatile memory  426 . The network adapter  422  receives  601   a  message from the network and relays it to the controller  421  which checks  602  to see if it is a request for energy usage status. If it is not, the controller  421  processes  603 , whatever the message is, and then waits  604  for the next message. If it is a request for energy usage status, the controller  421  examines  606  the request to see if it is a request for the current power being used by the networked device or if it is a request for the amount of energy used over a given period of time. If it is a request for the current power used, several different techniques can be used, depending on the set of power usage data stored in non-volatile memory  426  and the accuracy required by a particular embodiment. The flow chart  600  shows a method where the controller  421  ascertains  607  the current operating condition of the networked device and then searches the set of power usage data to find  608  the two data points closest to the current operating condition. If one of the data points exactly matches a stored data point, the power given for that data point can directly become the estimate of current power used. If the current operating condition does not exactly match a data point from the set of power usage data, the controller  421  interpolates  609  between the two closest data points in the power usage data set. As an example for the networked light bulb  300 , if the current operating condition is 60% brightness and the two closest data points are (50, 2.0) and (75, 2.5) the controller would determine that 60% brightness is 40% of the way between 50% brightness and 75% brightness and would then calculate the estimate of the current power by adding the power level at 50% to 40% of the difference between the power levels at 50% and 75% as shown in the following equation: 2.0+0.4*(2.5−2.0)=2.0+0.4*0.5=2.0+0.2=2.2 W. In other embodiments, the data point from the power usage data nearest to the current operating condition may be used instead of interpolating values, in this example, the 50% brightness operating condition leading to a power estimate of 2.0 W. In other embodiments where only a single point is included in the set of power usage data, that data point may be used as the estimated power for all cases where the networked device is considered “On” and zero (or some other low value determined by a constant when the instructions for the controller where created) used as the power estimation for cases where the networked device in “Off” or in standby mode. Once the estimation of the current power has been completed, the estimate is sent  610  over the network to the device that made the original request and the networked device then waits  604  for the next network message. 
     If the request is for the energy used over a period of time, the controller  421  retrieves  611  the log of operating conditions from memory. It must then determine the amount of time to use for the energy calculation. In some embodiments, the amount of time will be explicitly included with the request. In other embodiments the amount of time may be implicit, and the controller  421  then makes a calculation based on the instructions created at the time the networked device was designed. For this example, the request explicitly requests the power usage from the last hour. The controller starts with the most recent entry of the log of operating conditions and determines  612  the power used by the networked device at that operating condition using the methods described above for estimated the current power used. The power determined is then multiplied  613  by the amount of time (converted to hours) represented by that entry in the operating condition data structure. If the method of  FIG. 5A  was used, the time between the current time and the time stored in the data structure must be used for the first entry and the difference in the time entries between adjacent entries used for other entries. If the method of  FIG. 5B  was used, each entry constitutes an equal amount of time. If that method was used, an additional energy factor for the energy used between the last entry of the log and the current time may be added using the current operating condition for more accuracy in some embodiments. A running sum of the energy used for each entry in the log is kept. The time of the next entry in the log is examined  614  to see if enough data from the log has been analyzed to cover the period requested. If another entry is required, the power level for that entry is determined  612  and multiplied  613  by the time and summed. In some embodiments the amount of time for the operating condition entry will be determined by the length of time requested for the energy calculation. For example, if the first entry in the log of current operating conditions is from 4 hours ago because the networked device has not been used since then, the power estimation will multiply the power level for the operating condition stored in the first entry of the log multiplied  613  by 1 hour in the current example because that is the period requested, even though the first entry in the log is 4 hours earlier. In some embodiments, the networked device may not maintain a log of operating conditions. In those embodiments, the networked device may simply use the current operating condition as the operating condition for the entire period requested or may simply use a fixed average power usage value multiplied times the period to come up with an estimate. Once the estimation of the energy used has been completed, the estimate is sent  610  over the network to the device that made the original request and the networked device then waits  604  for the next network message. 
       FIG. 7  shows a set of networked devices in the networked home  100  that is used for an example of how the energy usage status estimation methods described above may be used. A computer  140  running a power management console application with display  700  is connected to a gateway device  124 . The gateway device  124  has a computer interface  124   a  that allows communication with a standard personal computer. The interface  124   a  can support any method of communication including but not limited to USB, Ethernet, IEEE-1394, Wi-Fi, Power line networking or any standard or proprietary communication means. The gateway device  124  has its own controller  124   c  and a network adapter  124   n  to allow it to connect to the network  130  and communicate with the networked devices  111 - 127 . The power management console  700  may query the network controller  120 , communicating with its controller  120   c  through its network adapter  120   n , to determine what networked devices  111 - 127  are currently available on the network  130 . For this example, the network controller  120  provides information to the power management console  700  that the light bulb  115 , the floodlight  117 , the refrigerator  123  and the television  125  are available and support energy usage status requests. 
     The power management console than sends a request for the energy used over the last 24 hours to the floodlight  117  because it has not been available for requests for some time and the power management console  700  does not have any recent information. The power usage request then goes through the network from the gateway&#39;s network adapter  124   n  to the floodlight&#39;s network adapter  117   n . In this embodiment, the network is a mesh network so the message may be routed through other networked devices to be properly delivered to the floodlight  117  as described above in the descriptions of  FIG. 1  and  FIG. 2 . Once the floodlight&#39;s controller  117   c  gets the request, it estimates the power used over the last 24 hours. In this example, the floodlight is not dimmable and it only has two entries in its set of power usage (0.05 &amp; 15). Its first operating condition log entry was turning on 20 minutes ago and the next entry was turning off 36 hours earlier. So the controller uses that data to estimate an energy usage of 23.67*0.05+0.33*15=6.18 Wh and returns that information to the power management console  700  which may store the estimate in a database. 
     The power management console  700  then determines that it only needs the last 2 hours of energy usage from the networked light bulb  115 , so it sends a request over the network  130  to the light bulb&#39;s network adapter  115   n , the light bulb&#39;s controller  115   c  retrieves the log of operating conditions which has an entry every 15 minutes and shows that over the last 8 entries covering the two hour time period of interest, the light bulb has been at full brightness for 6 of those entries and at 30% brightness for the other two entries. The controller  115   c  then gets the set of power usage data and finds a single entry of 20 W so it estimates the energy used over the last two hours by interpolating the power used when the brightness was 30%. It interpolates between 0 and 20 W to get 6 W for a brightness level of 30% and multiplies it by the 0.5 hour time for two periods to come up with an estimate of 3 Wh used for that 0.5 hour time period. It then adds that to the energy used during the 1.5 hours that the light bulb was at full brightness, 20*1.5=30 Wh to get an estimate of 33 Wh used for the 2 hour time period and returns the estimate to the power management console  700 . 
     The power management console  700  has been pre-programmed in this example to query the refrigerator  123  with network adapter  123   n  and controller  123   c , and the television  125  with network adapter  125   n  and controller  125   c  only once every 24 hours and since the television  125  was queried 4 hours ago in this example, the power management console  700  does not query the television  125  at this point in time. It is due to query the refrigerator  123 , so it sends a request for the energy used by the refrigerator over the last 24 hours over the network  130 . The refrigerator&#39;s controller  123   c  receives the request from the network adapter  123   n . The refrigerator&#39;s set of power usage data has a single data point giving the power used with the compressor is running (600 W). The log of operating conditions stores one entry each hour showing how many minutes the compressor has run. So the controller  123   c  goes through the last 24 entries of the log and multiplies the number of minutes of each entry by 600/60, accumulating the total, estimating that the refrigerator has used 800 Wh over the last 24 hours, and send the estimate to the power management console. 
     The power management console  700  may display the information it has received and stored in a database in many different ways to help the homeowner determine how to utilize her home in a way to be more “green”. One display is a simple bar chart showing the energy used in the last month by each device. Other displays may show the highest peak users or the amount used by each networked device when electrical rates are at their highest. In some embodiments, the power management console  700  may be able to communicate with the networked electric meter  126  to get the total electrical usage of the home as well as possibly receive messages from the electrical utility. Different embodiments of the power management console  700  may provide a wealth of other information. 
     The networked devices described thus far do not actually measure the power they use during normal operation. They simply estimate their power usage based on a set of power usage data stored in the networked device and readily available information on what the networked device is doing so that no additional circuitry is required to actually measure the power used. Some embodiments may determine that it is important to measure power used more accurately than can be estimated.  FIG. 8  shows an embodiment of such as networked light bulb  800 . The networked light bulb  800  is connected to a power source  801  and includes a light source  803 , a CPU  804  and wireless network adapter  805  connected to the CPU by a digital bus  806 . The CPU  804  of this embodiment includes memory that can be used for a log of power used. This networked light bulb  800  has included measurement circuitry  802  as well as including a switch  824  controlled by the CPU  804  using a control line  825 . The measurement circuitry  802  also includes an ammeter  822  read by the CPU  804  through communication means  823  and a voltmeter  820  read by the CPU  804  through communication means  821 . The light source  803  is connected to the power source with a neutral line  811  directly connected and the hot line  810  connected through the ammeter  822 , switch  824  and a conductor  812 . Whenever the switch  824  is closed, the ammeter  822  measures the current flowing through the light source  803  and the voltmeter  820  measures the voltage across the light source  803  from the hot line  810  to the neutral line  811 . The CPU can the multiply the values received from the ammeter  822  through communication means  823  and the voltmeter  820  through communication means  821  to determine the actual current power being consumed by the light source  803 . This may give the most accurate power reading possible, but the added expense and complexity may not be worth it in many instances. The estimation methods disclosed herein may give results that are nearly as accurate as actually measuring the power with no added circuitry beyond what is required for the other operations of the networked device. 
     Unless otherwise indicated, all numbers expressing quantities of elements, optical characteristic properties, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the preceding specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviations found in their respective testing measurements. 
     The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). 
     As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to an element described as “an LED” may refer to a single LED, two LEDs or any other number of LEDs. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     As used herein, the term “coupled” includes direct and indirect connections. Moreover, where first and second devices are coupled, intervening devices including active devices may be located there between. 
     Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specified function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, ¶ 6. In particular the use of “step of” in the claims is not intended to invoke the provision of 35 U.S.C. §112, ¶ 6. 
     The description of the various embodiments provided above is illustrative in nature and is not intended to limit the invention, its application, or uses. Thus, variations that do not depart from the gist of the invention are intended to be within the scope of the embodiments of the present invention. Such variations are not to be regarded as a departure from the intended scope of the present invention.