Abstract:
An automatic plant watering apparatus having a cavity for receiving a standard houseplant pot, a reservoir for holding water, a pump for removing water from the reservoir, a host for delivering water from the pump to a plant positioned in the cavity. The pump is operated by a microcontroller that is programmed to measure a first time period during which the pump is not operated, and a second time period during which the pump is operated. According, the apparatus can be programmed to automatically water a house plant at predetermined intervals, as well as deliver a predetermined amount of water.

Description:
The present application claims priority to U.S. Provisional Application Ser. No. 60/594,320, filed on Mar. 29, 2005. 

   FIELD OF THE INVENTION 
   The invention relates generally to the field of horticulture and more specifically to the areas of hardware intended for the care and maintenance of house plants. 
   BACKGROUND OF THE INVENTION 
   Many people grow plants in their homes. House plants need water to survive. However, people often travel and thus people who keep plants in their homes are not always home to water them. It is often true that many people also simply forget to water their plants and as a result the plants wither and die. It would, therefore, be useful to have a device that would automatically water a plant at regular intervals. As many people take extended vacations and are away from home for days or weeks, the present invention would be able to provide the plant with water while the owner was away, or otherwise relieve the owner of the task of periodic watering. 
   There are numerous devices having pumps and timers for watering plants, and certainly such systems exist for watering lawns and gardens. Commercial systems also exist for watering fruits and vegetables inside grocery stores. However, none of these systems provide for automatically and regularly watering house plants and the like with predetermined amounts of water while the owner is away or otherwise preoccupied. 
   OBJECTS OF THE INVENTION 
   The primary object of the present invention is to prove an automatic watering device for house plants, said device consisting of a reservoir, a pump, a controller and a power source operatively connected to allow a selected amount of water to be delivered to the plant at any number of predetermined intervals. A further object of the invention is to provide a reservoir shaped in such a fashion as to hold the plant and its pot. Another object of the invention is to provide for the watering of multiple plants. Yet another object of the invention is to optionally provide for an AC powered pump. A further object of the invention is to provide a similar device for outdoor use wherein the pump&#39;s batteries are augmented with solar cells and the soil containing the plant is monitored to prevent over watering. 
   SUMMARY OF THE INVENTION 
   In accordance with the foregoing objects and advantages, the present invention comprises a water tank (reservoir) operatively constructed with a cavity to accept a standard size pot for a houseplant. Houseplants are commercially available in several standard size containers. Generally, 4 inches to 10-inch diameter tapered pots are the most popular. The reservoir device of the present invention is also fitted with a filler plug and attachments points for an optional hanger. Near the bottom of the reservoir tank, an output tube is operatively connected to a pump driven by a low voltage motor, which is controlled by an microcontroller, and powered by a battery or batteries. A flexible hose is interconnected to the output of the pump and placed in communication with the plant to be watered. The microcontroller circuit is designed to allow the pump to start and stop at regular intervals, selected either at manufacture or (in an alternate embodiment) by the user. The interval at which the pump is activated is, of course, the number of times a day the plant receives or is supposed to receive water. The duration of the pump&#39;s “on” time determines the amount of water the plant receives. Both the interval and duration of pumping are functions of the microcontroller. 
   It should be noted here that having a built-in plant cavity in the reservoir tank (while useful to contain overflow and seepage) is not strictly necessary for the utility of this device. Said plants could easily sit outside the reservoir as long as the watering tube can reach them. Further several pump device can be attached to a single reservoir for the purpose of watering several plants simultaneously. Since the controller is a microprocessor-based circuit, the program written for it to execute determines its functionality. The controller&#39;s primary function is to turn the pump motor on and off at programmed intervals and durations. A detailed description of the controller and its program will be found later in this application. For simplicity, both interval and duration times are fixed in the sample program submitted, although it should be noted that the program can take additional inputs, and based on these inputs, alter either or both of the interval and duration parameters. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a self-watering apparatus according to the present invention. 
       FIG. 2  is a schematic of control circuitry according to the present invention. 
       FIG. 3  is a side view of an alternative embodiment according to the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings, wherein like numerals refer to like parts throughout, there is seen in  FIG. 1 , a reservoir tank  1  comprising a hollow vessel operatively constructed to hold water and to be filled by removing filler plug  2 . Reservoir  1  can be of any size or shape but preferably constructed to allow the inclusion of a plant holder cavity  3 , the size of which corresponds to that of a standard size flowerpot. In this embodiment, the example cited is that of a 10-inch circular tapered pot  12 . The size of reservoir  1  is therefore determined by the size of the pot  12  and also the amount of water  4  it is designed to hold. Reservoir  1  is fitted with attachment points  6  for hangers  11  in the event the user wishes to hang the plant instead of setting it on a surface. Output tube  13  is located near the bottom of reservoir  1  and is operatively connected to pump  10 . By locating the input of pump  10  near the lower level of the water supply, pump priming issues are negated or minimized. 
   A low voltage direct current motor  9  drives pump  10 . Flexible output tube  5  is positioned over the plant once pot  12  is placed in the holder. Controller  8  receives its power from battery  7  and, under program control, counts a predetermined interval in hours, minutes and seconds. Upon completion of that interval, pump  10  is turned on for a predetermined duration. The rate of water delivery by pump  10  is determined by design and testing and once determined the amount of time the pump is on, i.e., the duration can be determined and programmed into the controller. The present program is set to deliver one-half cup (8 oz.) of water to the plant at twelve-hour intervals. 
   Referring to  FIG. 2 , microcontroller  21  can be commercially available low power unit, such as Motorola 68HC705KJ1. Battery  23  supplies 3 VDC to operate the process. On/off switch  24  is included to turn the unit off when operation is not desired. R 1 , C 1 , R 2  and C 2  are common components necessary for proper startup and operation of the processor. Crystal  25  sets the processors operating frequency at 32.768 kilohertz, a convenient frequency from which to develop a time base measured in seconds. R 6 , R 7 , C 3  and C 4  are components of the oscillator circuit necessary to sustain oscillation at the correct frequency. Also the use of this frequency allows the processor to operate at very low current level. This, along with power saving programming techniques allows for a sufficiently long battery life in the order of a year or more of continuous use. The processor pin labeled PB 2  flashes the attached LED  9  once every 5 seconds as an indication to the user that the system is working. The processor pin labeled PB 3  is attached through resistor R 8  to transistor Q 1   28 . When this pin goes HIGH, the transistor is turned on allowing current to flow from Battery  26  through motor  27  to ground, causing the motor to spin. Causing the pin to go LOW shuts the motor off. C 5  and D 2  are included to mitigate electrical motor noise. The length of time PB 3  is held high by the program is the “pump duration time.” Battery  26  is separate from battery  23  since the motor requires a much higher current level than the processor to operate. Battery  26  is considered here to be a single standard “D” cell that will operate the pump motor for about a year. Batteries  23  and  26  can be replaced by design with larger or smaller capacity units as needed for various applications. 
   An assembly language program used by the processor is included hereinafter.  FIG. 3 . Software program 
   
     
       
             
           
             
             
           
             
             
           
             
           
             
             
             
           
             
             
             
           
             
             
           
             
             
             
           
             
             
           
             
             
           
             
             
             
           
             
             
           
             
             
             
           
             
           
             
             
             
           
             
             
           
             
             
             
           
             
             
             
           
             
             
             
           
             
           
             
             
           
             
             
             
           
             
           
         
             
                 
             
           
           
             
               ; PROGRAM NAME kjpump2.asm 
             
             
               ; MODIFIED KJPUMP 5/6/04 
             
             
               ; ORIG -04/26/2004 
             
             
               ; CIRCUIT IS INTENDED TO RUN WITH 32.768 KHZ XTAL 
             
           
        
         
             
               BLINK 
               EQU $C1 
             
             
               SEC 
               EQU $C2 
             
             
               MINUT 
               EQU $C3 
             
             
               HOURS 
               EQU $C4 
             
             
               PUMPON 
               EQU $C5 
             
             
               PFLAG 
               EQU $C6 
             
             
               TOF 
               EQU $C7 
             
             
                 
               ORG $300 
             
           
        
         
             
                 
               ; ---- SET UP PORT DATA AND DDR&#39;S 
             
             
                 
               ; ---- DATA---- 
             
           
        
         
             
               SETUPLDA #$00 
             
           
        
         
             
                 
               STA 00 
               ;PORT A DATA 
             
             
                 
               LDA #$04 
             
           
        
         
             
                 
               STA 05 
               ;PORT B 
             
             
                 
               CLR  TOF 
             
             
                 
               CLR  BLINK 
             
             
                 
               CLR  SEC 
             
             
                 
               CLR  MINUT 
             
             
                 
               CLR  HOURS 
             
             
                 
               CLR  PUMPON 
             
             
                 
               CLR  PFLAG 
             
           
        
         
             
                 
               ;---INITIALIZE TIMER OVERFLOW INTERRUPT---- 
             
           
        
         
             
                 
               CLR  $08 
               ;TIMER STATUS AND CONTROL REGISTER 
             
             
                 
               BSET 5,08 
               ;ENABLE TMR OVERFLO INTERRUPT 
             
             
                 
               BCLR 3,01 
               ;PUMP OFF 
             
             
                 
               BSET 2,01 
               ;LED OFF 
             
             
               IDLE 
               NOP 
             
             
                 
               WAIT 
               ; GO INTO LOW POWER MODE WAITING FOR TMR INTERRUPT 
             
           
        
         
             
                 
               BRSET 1, PFLAG, PUMP 
             
             
                 
               JMP IDLE 
             
           
        
         
             
               PUMP BSET 3,01 
               ;TURN THE PUMP ON 
             
           
        
         
             
                 
               CLR PUMPON 
               ;RESET ON TIME REGISTER 
             
           
        
         
             
               P2 
               LDA PUMPON 
             
           
        
         
             
                 
               CMP #$1E 
               ;DECIMAL 30 [30 SECONDS] 
             
             
                 
               BNE P2 
             
             
                 
               BCLR 3,01 
               ;PUMP OFF 
             
             
                 
               JMP SETUP 
             
           
        
         
             
               ;----Timer Interrupt Service Routine ---------- 
             
           
        
         
             
               TISR 
               BSET 3,08 
               ;RESET THE TMR OVERFLO FLAG 
             
             
                 
               BCLR 3,08 
             
             
                 
               INC TOF 
               ;COUNT TIMER OVERFLOWS 
             
             
                 
               LDA TOF 
             
             
                 
               CMP #$0F 
               ;16 TIMES=1 SECOND 
             
           
        
         
             
                 
               BNE TMOUT 
             
             
                 
               CLR TOF 
             
             
                 
               INC SEC 
             
           
        
         
             
                 
               INC PUMPON 
               ;INCREMENT PUMPON EVERY SECOND 
             
             
                 
               INC BLINK 
             
             
                 
               LDA BLINK 
             
           
        
         
             
                 
               CMP #$05 
               ;BLINK LED EVERY 5 SECONDS 
             
             
                 
               BNE TSR2 
             
             
                 
               BCLR 2,01 
               ;LED ON 
             
             
                 
               BSET 2,01 
               ;LED OFF 
             
             
                 
               CLR BLINK 
             
             
               TSR2 
               LDA SEC 
             
             
                 
               CMP #$3C 
               ;DECIMAL 60 [60SEC OR 1 MINUTE] 
             
             
                 
               BNE TMOUT 
             
             
                 
               CLR SEC 
             
             
                 
               INC MINUT 
             
             
                 
               LDA MINUT 
             
             
                 
               CMP #$3C 
               ;DECIMAL 60 [60 MINUTES =1 HOUR] 
             
             
                 
               BNE TMOUT 
             
             
                 
               CLR MINUT 
             
             
                 
               INC HOURS 
             
             
                 
               LDA HOURS 
             
           
        
         
             
                 
               CMP #$0C 
               ;DECIMAL 12 {@12 HOURS DO PUMP SUBROUTINE} 
             
             
                 
               BNE TMOUT 
             
             
                 
               CLR HOURS 
             
             
                 
               BSET 1, PFLAG 
               ;SET PUMP FLAG ON AT 12 HOUR INTERVALS 
             
           
        
         
             
               TMOUT RTI 
             
             
               ;------------------- 
             
           
        
         
             
               EXTINT 
               RTI 
             
             
               SWI 
               RTI 
             
             
                 
               ORG $07F1 
             
           
        
         
             
                 
               DB $08 
               ;SOSCD DISABLED 
             
             
                 
               ORG $07F8 
             
             
                 
               DW TISR 
             
             
                 
               DW EXTINT 
             
             
                 
               DW SWI 
             
             
                 
               DW SETUP 
               ;RESET 
             
             
                 
               END 
             
           
        
         
             
               ;----------------------------------------------------------------------------- 
             
             
                 
             
           
        
       
     
   
   A 32.768 KHz clock is a convenient frequency to use when trying to establish a time base. As 1/32.768 kHz equals 244.14 microseconds and the processor&#39;s timer overflows every 1024 clock cycles, each timer overflow is equal to 0.25 seconds. In the sample processor, the timer overflow can be made to generate an interrupt, allowing the process to enter a low power “wait” mode until interrupted by the timer. The reason for this is to assist in reducing battery current draw. The object of the program is to initially set up it&#39;s internal registers and then to begin counting timer overflows (240 overflow interrupts equal 1 minute). As each interrupt occurs, a “blink” register is incremented and compared to 5. When equal the processor causes the LED to flash for approximately 1 millisecond, giving a visual indication that the device is functioning. The “blink” register is then cleared. Also as each interrupt occurs, a “seconds” register is incremented and compared to 240. When equal, it is cleared and the “minutes” register is incremented and compared to 60 (1 hour). When equal, the “minutes” register is cleared and the “hours” register is incremented and compared to 12. When equal, the program jumps to the “pump” routine and starts the pump motor running. As the “pump” routine starts, the “seconds” register is cleared and allowed to increment at each timer interrupt until the “duration” is reached. In the sample program reproduced above, the pump is allowed to run for 30 seconds. When the pump is turned off, the program is sent to the beginning of the program in order to begin another 12-hour cycle. Again it should be noted here that the processor has 8 inputs which can be set to either 1 or 0 by means of a switch on each line or by physically opening or shorting the line with a wire or circuit trace. As the “interval” and “duration” numbers are variables in the program, the program can be written to read the input port (PB 0 -PB 7 ) and alter the interval and duration variables according to the value it reads from the port. Thus, up to 255 variations can be accommodated in the program. 
   The above description is a simple embodiment of the concept. Several variations on the theme are possible, practical and useful. Referring to  FIG. 3 , more than one pump  10  can be connected to a common reservoir  1  and be controlled by a common processor  8  or by separate processors  8  in order to service several plants simultaneously. Outdoor versions could also be implemented using the same techniques. Solar panels could be included to augment the batteries. Moisture sensors can be easily implemented to measure the water content in the soil and prevent “on schedule” watering when not necessary as in the case of a rainy day. As an outdoor version is quite likely to encounter rain, provisions can be made in the physical design of the reservoir to collect rainwater to augment the water level in the tank. 
   Another useful adaption on this theme is to provide a secondary reservoir  1  and pump  8  strictly for the purpose of delivering liquid fertilizer to the plant. Given the long lengths of time that the processor can measure, this secondary system could easily fertilize the plant on a weekly, monthly or longer schedule. Additionally, the DC pump motor  10  can be replaced with an AC submersible pump in applications where a source of AC power is available. Changes to the motor switching circuit may become necessary and the switching transistor circuit ( FIG. 2 ) could be replaced with means suitable for switching alternating current. For example the transistor circuit could be replaced with a Silicon Controlled Switch (SCS) or an optically coupled relay, etc. all of which are able to be driven by the existing microcontroller. 
   It should be clear from the foregoing descriptions that many variations on the theme are possible and feasible. This application seeks to describe one simple form of the invention for the sake of clarity. It is expressly understood that variations on the implementation of the system described can be made without departing from the spirit and scope of the invention.