Abstract:
A simple single- or multi-station sprinkler controller is set to various run times and watering intervals by the repetitive operation of pushbuttons or combinations of pushbuttons. The chosen settings are communicated to the operator by illumination patterns of LEDs. The patterns may include groups of flashes, sequential scrolling of LEDs, multicolored illumination of an LED, and steady illumination or non-illumination of selected LEDs. If a short occurs in a station, the controller shuts itself off and flashes a pattern that signals a shorted condition and identifies the shorted station. On power-up, run times and intervals are automatically set to generally-usefll default values.

Description:
RELATED CASES 
     This is a continuation-in-part of application Ser. No. 09/510,489 filed Feb. 23, 2000, which in turn is a regular filing corresponding to Provisional Application Serial No. 60/121,220 filed Feb. 23, 1999. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to irrigation controllers, and more particularly to a single-or multi-station controller which is inexpensive and easy to program, and which uses only a minimal set of pushbutton controls and visual indicators to carry out and indicate relatively complex programming functions. 
     BACKGROUND OF THE INVENTION 
     A large variety of controllers are commercially available for controlling the automatic operation of irrigation sprinklers in residential and industrial applications. These controllers vary in complexity and cost all the way from single-station, battery-powered units with few programming options that are mounted directly on a water valve, to complex, computer-programmable wall-mounted units capable of operating a complex irrigation system with many stations that require different operating parameters. Existing controllers are generally complicated and time-consuming for an unskilled owner to program. This causes many home controllers to be set once upon installation, and not to be periodically readjusted to fit changing conditions. 
     For this reason, and also because of the price consciousness of most homeowners, a need exists for both a single-station and a multi-station controller that is simple and inexpensive, powers up with a useful default set of operating parameters upon installation, and is simple to set to different parameters at any time. 
     SUMMARY OF THE INVENTION 
     The present invention fills the above-described need by providing, in the first two embodiments described herein, a multi-station controller with three actuators such as pushbuttons that select, respectively one of a set of predetermined combinations of water cycle length and repetition rate (i.e. the number of days between watering cycles); a start time-of-day; and a manual operation. On power-up, the inventive controller defaults to a generally appropriate cycle length, repetition rate and start time, which can then be changed by pushing the buttons. Alternatively, with an extra button as shown in the second embodiment, the watering time for each station can be set individually. 
     Operational parameter settings and controller status are indicated in the inventive controller by a set of simple indicators such as lights or light-emitting diodes (LEDs), preferably at least one for each cycle (in the first embodiment) or station (in the second embodiment), which convey information by their combinations and actions (e.g. scrolling, illumination, flashing and/or blinking). 
     If only a single station is to be controlled, as in the third embodiment described herein, the functions of the controller can be performed with only two pushbuttons, by using one or both pushbuttons. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation of the face plate of a preferred embodiment of the invention; 
     FIG. 2 is a block diagram of the circuitry of the controller of FIG. 1; 
     FIG. 3 is a flow chart of the operation of the microcontrollers of FIGS. 2 and 5; 
     FIG. 4 is a front elevation of the face plate of an alternative embodiment of the invention; 
     FIG. 5 is a block diagram of the circuitry of the controller of FIG. 4; 
     FIG. 6 is a front elevation of the face plate of a third embodiment of the invention; 
     FIG. 7 is a block diagram of the circuitry of the controller of FIG. 6; 
     FIG. 8 is a partial flow diagram of the microprocessor of FIG. 7 illustrating the use of the pushbuttons of FIG. 6; 
     FIG. 9 is a front elevation of the face plate of a fourth embodiment of the invention; 
     FIG. 10 is a front elevation of the face plate of a fifth embodiment of the invention; 
     FIG. 11 is a block diagram of the circuitry of the controller of FIG. 11; and 
     FIG. 12 is a flow chart of the operation of the microcontroller of FIG.  11 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates the simple face plate  10  of a representative embodiment of the invention. At the bottom of the face plate  10 , connectors  12  are the power inputs to the inventive controller (typically 24 V AC for safety); connector  14  is the common ground for the four watering stations; and connectors  16 ,  18 ,  20  and  22  are the switched terminals of the four watering stations. 
     Pushbutton  24  sets the watering cycle length and repetition rate; pushbutton  26  sets the start time; and pushbutton  28  starts a manual cycle. Indicator lights  30 ,  32 ,  34  and  36  provide information on the controller status and settings as described below. 
     The controller of this invention is intended for the homeowner market. Consequently, simplicity of operation and low cost are dominant considerations, even though they come at the expense of versatility. In this regard, it has been found that homeowners with little gardening skills or interest, at least in the warmer climates, do not care to repeatedly fine-tune their sprinkler systems. Such homeowners are only interested in setting their sprinklers to seasonal changes in watering conditions, to run them manually when necessary, or to turn them off during protracted periods of rain. It is therefore possible to determine, based on the climatic conditions of a particular market, a set of cycle length and repetition rate parameters that is generally suitable for a given season in that market. 
     The present invention makes use of this fact in reducing the complexity and cost of a controller by combining cycle lengths and repetition rate settings into a set of single settings such as heavy (summer), medium (spring/fall) and light (winter) watering. Thus, the homeowner merely needs to select a-watering level and a start time, and the controller does the rest. To accommodate special situations, a no-watering setting and a manual start for a selected station or stations are provided. 
     FIG. 2 outlines the overall architecture of the controller of this invention. 24V AC power is applied to terminals  12 . The input power operates a 5V DC power converter  40  which powers the control electronics of the controller. A battery  42  may be connected to the converter  40  as a stand-by power source if desired. 
     A short circuit detector  44  monitors the current drawn by each station output  16  through  22  from the input  12  for one full AC cycle, i.e. 16.7 ms, on power-up, and also monitors it continually whenever a station is on. If an overcurrent indicative of a short circuit occurs, the detector  44  sends a signal to the microcontroller  46  to shut off all stations and flash all the LEDs  30  through  36  with a blinking code indicating the station which was energized when the short was detected. 
     The internal clock for the microcontroller  46  is provided by an oscillator  48  which, in the preferred embodiments, operates at 32.768 kHz in order for the clock timer to synchronize with real time. The operations of microcontroller  46  are controlled, as detailed below, by the pushbuttons  24 ,  26  and  28 . The outputs of microcontroller  46  are the lines  50  to the LEDs  30  through  36 , and the lines  52  which selectively enable one of the station outputs  16  through  22  to be connected to the power input  12 . 
     FIG. 3 shows the basic operation of the microcontroller  46 . Upon power-up or a watchdog timer reset, the microcontroller&#39;s ports and registers are initialized to their default settings, which preferably include the medium watering cycle and a start time of twenty-four hours after power-up. The LEDs  30  through  36  are set to scroll. The microcontroller&#39;s built-in watchdog timer (WDT) is scaled to about 1 second. Each station is next sequentially checked for short circuits as described above, and the WDT is started. If a short circuit has been detected, the controller is disabled and the short-indicating LEDs are set to flash with a blinking code indicative of the station on which the short circuit was detected, i.e. once for station  16 , twice for station  18 , three times for station  20 , and four times for station  22 . 
     If a short circuit is not detected on the power-up test, the program next resets the WDT and tests to see if a pushbutton has been pressed. If one has, the program updates the microcontroller register status indicated by that pushbutton. In either event, the program next updates the microcontroller&#39;s event timing clock registers. On each main loop iteration, which is preferably programmed to be 31.25 ms, the program increments and checks the timing registers. Once the seconds timing register has been incremented to indicate that a minute has elapsed, the program checks and updates the station status and LED status based on the parameters then selected or defaulted to, as the case may be. Once the minutes timing register has been incremented to indicate that an hour has elapsed, the program checks whether the start time has been reached and whether the present day is the correct day for watering. If both are true, the program initiates a watering cycle. 
     On each iteration of the program&#39;s main loop, the program, station, and LED statuses are updated, and the program then waits for the next iteration. Inasmuch as the WDT is reset on each 31.25 ms iteration, it does not time out unless a software glitch stops the iteration of the main loop in FIG.  3 . In that case, the WDT does time out and resets the controller to the power-up mode. 
     The microcontroller program is preferably arranged to carry out the operation of the controller in accordance with pushbutton operation as follows: Upon power-up, the cycle setting defaults to medium watering, and the start time defaults to twenty-four hours from power-up. The four LEDs  30  through  36  flash in succession, i.e. scroll, thereby calling attention to the condition that power had shut off so that any previously selected start time and cycle settings were lost; and that, at the time power was restored, the start time and cycle setting reverted to their default values. When one of the pushbuttons  24 ,  26  or  28  is pressed, or a watering cycle starts, LED  34  lights and stays on. Each time a button is pressed, a short flash of all four LEDs  30  through  36  indicates that electrical contact has been made. The pushbuttons  24 ,  26  and  28  are preferably software-debounced in a conventional manner so that contact noise will not result in multiple operations. Software control also prevents continuous pressing from inadvertently causing the user to make an incorrect selection. 
     If a different watering cycle than medium watering is desired, pushbutton  24  must be pushed, repeatedly if necessary, to select high, low or no watering. 
     If watering is to start at a time of day different than the time of power-up, pushbutton  26  must be pushed. The first push resets the start time to twenty-four hours after that push. Each subsequent push of pushbutton  26  (made within a preset wait period) sets the start time back one hour from the first push. If, for example, a new start time of approximately 2:00 a.m. is desired and the current time is Tuesday, 10:15 a.m., a first push sets the time to 10:15 a.m. Wednesday. Eight additional pushes set the time back to 2:15 a.m. for Wednesdsay. An interval timer resets this function after a brief elapsed time, for example 10 seconds. If more than this time interval elapses between pushes of pushbutton  26 , the function resets and the next push sets the start time anew to twenty-four hours after the push. Once a start time has been chosen, any watering will always start every twenty-four hours from that time. 
     The controller now runs on its own. At the chosen start time, the four station connectors  16  through  22  are energized in sequence for the cycle length associated with the selected cycle setting. During this time, the LED associated with the chosen cycle setting repetitively flashes one blink while connector  16  is energized (Station  1 ), two blinks for connector  18  (Station  2 ), three blinks for connector  20  (Station  3 ), and four blinks for connector  22  (Station  4 ). 
     In one aspect of the invention, provision is made to prevent excessive watering (which may cause undesirable runoff) during any given cycle by limiting the length of uninterrupted watering that can occur. For example, if the maximum tolerable continuous watering time is six minutes but the selected watering schedule calls for 15 minutes of watering per cycle, the microcontroller will run station  16  (if selected) for six minutes, then stations  18 ,  20  and/or  22  (as selected) for six minutes each. It then runs station  16  for another six minutes, followed in like manner by stations  18 ,  20  and/or  22 . Finally, all the selected stations in sequence run for the remaining three minutes each If station  16  is the only station selected, the microprocessor inserts a five-minute break between the successive operations of station  16 . 
     In an alternative embodiment, all watering for each station may occur at one time without repeats, as for example in installations involving very porous soil. 
     If a start time is encountered while the controller is in the no watering or off mode, the entire watering cycle is inhibited, and the controller remains inactive until another mode is selected. No change to the controller&#39;s settings can be made while a cycle is in progress; thus, if a cycle is in progress when the user pushes button  26 , the controller&#39;s action will not change. 
     For manual watering, pushbutton  28  is pressed once. This immediately starts a watering sequence. Pressing pushbutton  28  again skips to the next station in the sequence. Pressing pushbutton  28  while terminal  22  is energized stops the manual watering. Manual watering may normally cause a single iteration of the stations for ten minutes each. Manual watering cannot be initiated while an automatic cycle is in progress. 
     During manual operation, the LED associated with the watering cycle currently selected for automatic operation blinks one or more times to identify the currently energized station. This makes it possible to check for open circuits or valve failures by monitoring the controller indication when a station fails to operate. 
     If a short circuit occurs in the wiring of a station, all four LEDs  30  through  36  repetitively flash together, blinking once if connector  16  is shorted, twice for connector  18 , three times for connector  20 , and four times for connector  22  to identify which station has the short. At the same time, the controller shuts off all stations to prevent a possibly damaging operation of the controller. Power must be turned off to remove this blinking even if the short condition is corrected. 
     FIGS. 4 and 5 illustrate an alternative embodiment of the invention. In the embodiment of FIGS. 4 and 5, each station is separately controllable as to the cycle duration, but the repetition rate is fixed at once a day. 
     As shown in FIG. 4, the alternative controller  54  has the same power input  12 , the same common station terminal  14 , and the same station outputs  16  through  22  as the controller  10  of FIG.  1 . The start button  26  and the manual button  28  also function in the same way as they do in the controller  10 . The difference between the embodiments of FIG.  1  and FIG. 4 is in the pushbuttons  56 ,  58  and in the LEDs  60 ,  62 ,  64 ,  66  and  68 . 
     In the embodiment of FIGS. 4 and 5, the controller  54  may, for example, default on power-up to ten minutes per station once each day. As in the controller  10 , the power-on default condition is signalled by a scrolling of the LEDs  60  through  68 . To change the default condition, button  56  is first pushed to select a station - once for Station  1 , twice for Station  2 , and so on. Pushing button  56  a fifth time turns the controller  54  off and lights the no-watering LED  60 . Any push of button  56  stops the scrolling, and the chosen station&#39;s LED repetitively blinks twice, indicating a ten-minute cycle duration. Button  58  can now be pushed one or more times to select the desired cycle length for that station. Successive pressings of button  58  will select 0, 5, 10 15, or 20 minutes. Each selection is confirmed by the repetitive blinking of the pertinent one of LEDs  62 - 66  with zero to four blinks, respectively. 
     If button  58  is not pushed for five seconds, or more, the program of button  58  resets, and the next push will again select 0 minutes. 
     In the block diagram of FIG. 5, the microcontroller  70  functions essentially as shown in FIG.  3 . The manual operation of controller  54  and its operation while a watering cycle is in progress are also essentially the same as described above in connection with controller  10 . 
     A third embodiment of the invention is directed at those installations in which a single station needs to be operated with little or no supervision in an environment in which power is not readily available. Because such a controller needs to rely on longterm battery power in humid or otherwise adverse environments, fail-safe circuitry with very low power consumption must be used. 
     An embodiment satisfying these requirements is shown in FIGS. 6 through 8. In its sealed waterproof case  78  (FIG.  6 ), the single-station controller  80  has a cycle selection button  82 , a start time selector button  84 , and a single LED  86 . The controller  80  is mounted on a conventional water valve  87  which is toggled between an open and a closed position by a plunger  88 . The plunger  88  is in turn toggled between the open and closed positions by a latching solenoid  90  (FIG.  7 ), which is operated by momentary “open” and “close” signals from a microprocessor  92 . Thus, the controller  80  consumes significant power only momentarily while switching from one valve state to the other. 
     The controller  80  is powered by a battery  94 . Because a battery failure while the valve  87  is open could be catastrophic, a battery power sensor  96  is provided in the controller  80 . When battery power drops below a predetermined safe level, the sensor  96  causes the cycle timer  98  in microprocessor  92  to close the valve  87  and lock itself in the “Off” mode until the battery  94  is replaced. 
     The microprocessor  92  includes four operational elements: an hours counter  100 , the cycle timer  98 , a valve actuator  104 , and an LED control  106 . The counter  100  cyclically counts off twenty-four one-hour intervals and then issues a start signal  108  to the cycle timer  98 . The cycle timer  98  preferably includes a day counter and five selectable timing routines: Off (no watering), Some (e.g. 5 minutes every third day), More (e.g. 10 minutes every other day), Most (e.g. 20 minutes every day, preferably applied in two 10-minute cycles with an hour&#39;s delay between them), and Manual (e.g. 10 minutes). These routines (other than Manual) can be selected in the cycle timer  98  by successive pushes of the cycle selector button  82 . The Manual routine is selected by pushing cycle selector button  82  and Start selector button  84  simultaneously. On power-up, the cycle timer  98  defaults to the More routine. 
     The cycle timer  98  provides “open” and “close” signals in accordance with the selected timing routine to the valve actuator  104 , which in turn operates the locking solenoid  90  to open or close the water valve  87 . 
     The LED control  106  causes the LED  86  to flash momentarily whenever button  82  or  84  is pushed, and to indicate the selected cycle routine by blinking, e.g. steady on for Off, one blink for Some, two blinks for More, and three blinks for Most. In Manual mode, the LED  86  remains off. In order to conserve power, the LED  86  is deactivated after five seconds. 
     FIG. 8 is a self-explanatory flow diagram illustrating the sequence of operation of the microprocessor  92 . It should be noted that each push of the start button  84  decreases the hours counter  100  by one hour, so that the initial start time can be adjusted but each subsequent start occurs twenty-four hours (or a multiple of twenty-four hours in the Some and More modes) after the previous one. If the start button  84  has not been pushed for five seconds or more, the next push resets the hours counter  100  to its original setting. 
     FIGS. 9 and 10 illustrate additional preferred embodiments of the invention allowing individual setting of a plurality of watering stations. The device of FIG. 9 includes a plurality (e.g. four) switched stations  16 ,  18 ,  20  and  22  with individual control panels  110 ,  112 ,  114  and  116  Each of these control panels contains one of four LEDs  118 ,  120 ,  122  and  124 , and one of four pushbuttons  126 ,  128 ,  130  and  132 . In addition, a start time button  134  and a manual button  136  are provided. 
     Using a microprocessor control similar to that described in connection with FIGS. 2 and 5, the controller of FIG. 9, like the controllers of FIGS. 1 and 4, defaults on power-up to a setting of medium watering (e.g. 7 minutes every other day) and a start time of 24 hours from power-up. This condition is signalled by a scrolling flashing of the LEDs  118  through  122 . 
     Each push of start time button  134  within a predetermined wait time decrements the start time of the first watering cycle by one hour from the 24-hour default, after which the watering cycles start at intervals of 24 hours or a multiple thereof from the first cycle. Pressing the manual button  136  starts a manual cycle or stops an automatic cycle. Each push while a station is running manually advances the cycle to the next station. Also like in the controllers of FIGS. 1 and 4, a short circuit in any station shuts off the controller and causes all of the LEDs  118  through  124  to flash simultaneously, with the number of flashes in each group of flashes identifying the shorted station. 
     In the controller of FIG. 9, the watering setting for each individual station is set by repeatedly pushing the respective button  126 ,  128 ,  130  or  132  to cycle the station through the available plurality of settings (e.g. Off: no watering; Low: 3 minutes every third day; Medium: 7 minutes every other day; and High: 12 minutes every day). The current setting is indicated by the flashing of the corresponding LED  118 ,  120 ,  122  or  124  in groups of one, two, three or four flashes depending on the selected setting. Although the Off setting could well be indicated by the absence of flashing, it is preferable to assign it one flash to prevent a misindication if the LED fails. 
     For users desiring greater flexiblity in setting the interval between watering cycles and the run time of any given station while retaining the simplicity of the controller, the embodiment of Fig. IO provides an additional LED  138 , and uses a combination of pushbuttons  132  and  134  to set the cycle interval separately from the station run times. 
     Specifically, in the device of FIG. 10, holding down the start time button  134  while pushing button  132  increases the cycle interval one day for each push of button  132 . The LED  138  indicates the selected interval setting by flashing in groups of one flash for each interval day. 
     Alternatively, the microcontroller  140  may be programmed so that start time button  134  must be held down until the interval LED flashes red, and button  136  must then be pressed to set the desired interval. 
     If the start time button  134  is not pushed, the pushbuttons  126  through  132  operate to set the run times for their respective stations. Each push of a button  126 ,  128 ,  130  or  132  increases the run time of its respective station by five minutes. Holding the button down, e.g. for three seconds, returns the run time to zero, i.e. turns the station off. The run time setting for each station is indicated by flashing of its associated LED  118 ,  120 ,  122  or  124  in groups of one flash for each 5 minutes of run time. More specifically, after one of the LEDs  118 ,  120 ,  122  or  124  flashes the run time value for that station, the next LED similarly flashes its run time value, and so on in a scrolling sequence across the LEDs  118 ,  120 ,  122  and  124 . For a station that is off, its associated LED may be steadily on or steadily off. If any of the pushbuttons  126  through  132  are not pushed within five seconds after the preceding push, any subsequent pushes cause new run time values to be entered for that station. 
     In installations that include drip irrigation systems, it may be necessary to run a station for two hours or more. Setting such a run time in five-minute increments, and checking it by counting flashes each representing five minutes of run time, would be awkward at best. In the controller of FIG. 10, this problem can be obviated by using a plurality of the pushbuttons  126  through  132 , and multicolor LEDs  118  through  124 . Such LEDs are commercially available. They show red if one lead of the LED is energized, green if the other is energized, and orange if both are energized. 
     Thus, different increments can be set by the pushbuttons and signalled by the LEDs. For example, if the manual button  136  in FIG. 10 is held down, pushing any of the buttons  126 ,  128 ,  130  or  132  causes the microcontroller  140  to cyclically set the run time increments produced by the pushing of buttons  126 ,  128 ,  130  or  132  alone to, e.g., 2 minutes (signalled by red LED light and useful for garden sprinkler systems), 10 minutes (green LED light, useful for rotating sprinkler systems), or one hour (orange LED light, useful for drip irrigation systems). The increment value thus selected is applied to all station settings, so that each push of a button  126 , 128 ,  130  or  132  alone will increment the run time of the corresponding station by the selected increment value. When the run times are set, the color of the LEDs  118  through  124  indicates the interval signified by each flash of the LED. For example, two orange flashes of an LED  118 ,  120 ,  122  or  124  indicate that the corresponding station is set for two hours. . 
     As shown in FIG. 11, the controller of FIG. 10 is operated by a programmed microprocessor or microcontroller  140  whose internal operation is illustrated by the flow chart of FIG.  12 . The microcontroller  140  is driven by an oscillator  142 . The frequency of oscillator  142  is set at 32.768 kHz for the reasons stated in the discussion of FIG. 2 above. 
     The inputs to the microcontroller  140  are the pushbuttons  126  through  134  and the valve short circuit (i.e. AC power overcurrent) detector  144 . The AC power supply  145 , which may advantageously be 24 V, also operates a 5 V DC power supply  146  for the microcontroller  140 . The outputs of microcontroller  140  are the power outputs  148  to the sprinkler valves  16  through  22 , the LED illumination controls  150  for the LEDs  118  through  124  and  138 , and the color control  152  for the LEDs  118  through  124 . 
     FIG. 12 illustrates generally the operation of the microcontroller  140 . On power-up or reset, the microcontroller program initializes all ports and registers at  154 , and causes LEDs  118  through  124  to scroll. It also starts the timer and momentarily checks each station  16  through  22  at  156  for short circuits. If a short circuit is detected, the program shuts off the controller at  158  and continually flashes the LEDs  118  through  124  to indicate, as described above, which station is shorted. 
     If no short circuit is detected, the program enters the main loop  160  and checks the status of the controller  140  every  250  ms at  162 . The status loop  163  checks and updates the LED flash status every second, the station status every minute, and the watering cycle start time status every hour. 
     When the clock time equals the cycle start time programmed by the operator (or 24 hours from power-up if the operator does not program any start time), a watering cycle in accordance with the flags set at  164  and  166  and the count of flash register  168  is initiated at  170 . If any valve station  16  through  22  is on at  171  when the start time is reached, a watering cycle is considered to be in progress, and the program returns to the main loop  160 . 
     The pressing of any button  126  through  134  at  172  results in the identification of the pressed button at  164  and the setting of the function flag associated with it. If it is the first button pressed after a power-up or reset, the scrolling of the LEDs  118  through  124  is also stopped at this point. Depending upon the operator&#39;s action, a special function flag may be set at  166 , and cycle timing registers may be incremented at  168  for the purposes discussed herein. 
     When the proper flags have been set by the pushing of the appropriate button or buttons, the next iteration of the main loop  160  executes the button function at  174  or other selected function at  175 . For example, the selected duration of watering for a given station may be entered into the memory of microcontroller  140 . Whenever any valve  16  through  22  is on, the main loop  160  continually checks it for short circuits every 250 ms. 
     It is to be understood that the exemplary irrigation controllers described herein and shown in the drawings represent only presently preferred embodiments of the invention. Indeed, various modifications and additions may be made to such embodiments without departing from the spirit and scope of the invention. Thus, other modifications and additions may be obvious to those skilled in the art and may be implemented to adapt the present invention for use in a variety of different applications.