#!/usr/bin/python

# Documentation:
# http://abyz.me.uk/rpi/pigpio/python.html
# https://docs.python.org/2/library/threading.html#event-objects

# start the pigpiod with:
#   systemctl enable pigpiod
#   systemctl start pigpiod

import  pigpio
import  time
import  threading

GPIO_NO = 4
GPIO_OUT = 26


def gpio_callback(gpio, level, tick):
    global evt
    evt.set()
    #print("gpio %d is %d , %d" % (gpio, level, tick))


def callback_method(pig, gpio_no, gpio_out):
    global evt
    pig.set_mode(gpio_no, pigpio.INPUT)   # make GPIO an input
    pig.set_mode(gpio_out, pigpio.OUTPUT)   # make GPIO an output
    pig.set_glitch_filter(gpio_no, 10000)   # debounce 10 msec

    evt = threading.Event()

    # set up a callback for the GPIO
    cb1 = pig.callback(gpio_no, pigpio.EITHER_EDGE, gpio_callback)

    # read initial state of the GPIO
    gp = pig.read(gpio_no)
    print ("initial: gpio %d is %d" % (gpio_no, gp))

    pig.write(gpio_out,1)
    while(1):
        try:
            evt.wait(9999999.0)
            evt.clear()
            # pulse LED on GPIO out for 100 msec
            pig.write(gpio_out,0)
            time.sleep(0.01)
            pig.write(gpio_out,1)
            #print "pulse gpio %d" % gpio_out
        except KeyboardInterrupt:
            print "Caught keyboard intr"
            break

    # cancel the callback
    cb1.cancel()

def main():
    pig = pigpio.pi()   # local gpios
    callback_method(pig, GPIO_NO, GPIO_OUT)

if __name__ == "__main__":
    main()