catozap.py

#!/usr/bin/env python

import time
from threading import Thread
try:
    import RPi.GPIO as GPIO
except:
    print("*** Exception importing RPi.GPIO - falling back on rpiDummy ***")
    from rpiDummy import GPIO as GPIO
    #raise

class CatoZap:
    def __init__(self, configObj):
        self.pinLst = configObj['waterPins']
        self.enabled = configObj['enabled']
        self.startFiring = False
        self.shutdown = False
        GPIO.setmode(GPIO.BCM)
        GPIO.setwarnings(False)
        for pinNo in self.pinLst:
            print("CatoZap.__init__() - setting up pin %s" % pinNo)
            GPIO.setup(pinNo, GPIO.OUT)
            GPIO.output(pinNo, GPIO.LOW)
            
        
    def _fire(self):
        if (self.enabled):
            print("CatoZap._fire()")
            try:
                for n in range(0, 10):
                    GPIO.output(self.pinLst[0], GPIO.HIGH)
                    for pinNo in self.pinLst[1:]:
                        GPIO.output(pinNo, GPIO.HIGH)
                        time.sleep(0.2)
                        GPIO.output(pinNo, GPIO.LOW)
                    time.sleep(0.2)
                    GPIO.output(self.pinLst[0], GPIO.LOW)
                print("CatoZap._fire() - water off")
            except:
                print("CatoZap._fire() - exception - calling stopFiring()")
                self.stopFiring()
                raise
        else:
            print("CatoZap._fire() - CatoZab not enabled in configuration object")

            

    def stopFiring(self):
        ''' Shut down the water - should be called if an exception is raised
        such as a keyboard interrupt so that we exit with the water off.
        '''
        print("Catozap.stopFiring()")
        for pinNo in self.pinLst:
            GPIO.output(pinNo, GPIO.LOW)
        

    def zapLoop(self):
        print("CatoZap.zapLoop()")
        while(1):
            if self.startFiring:
                self.startFiring = False
                self._fire()
            if self.shutdown:
                break
        print("CatoZap.zapLoop exiting")
        
    def start(self):
        ''' Run the zapLoop() function in a background thread - it waits
        for the fire() function to be called to initiate the firing
        sequence.
        '''
        print("CatoZap.start()")
        self.thread = Thread(target=self.zapLoop)
        self.thread.start()

    def stop(self):
        print("CatoZap.stop()")
        self.shutdown = True
        print("CatoZap.stop() - waiting for zapLoop to exit...")
        self.thread.join()
        
    def fire(self):
       self.startFiring = True       
        
    

if __name__ == "__main__":
    print("catozap main()")
    cz = CatoZap({"waterPins": [17, 27, 22], "enabled": 1})

    cz.start()

    for n in range(0,10):
        cz.fire()
        time.sleep(2)

    print("sleeping")
    time.sleep(3)
    print("shutting down cz")
    cz.stop()
    print("finished..")