RPi Chasing Lights

chasing_lights.py

#!/usr/bin/env python

import signal
import sys
import time
from RPi import GPIO

LIGHT_ORDER = (7, 12, 16, 18, 22, 11,) # The number of the GPIO pins in the order lights are wired to them
DELAY = .05


def exit(signal, frame):
	for light in LIGHT_ORDER:
		GPIO.output(light, GPIO.LOW)
	GPIO.cleanup()
	print "\n"
	sys.exit(0)


def main():
	# Set Up the GPIO board
	GPIO.setmode(GPIO.BOARD)
	for light in LIGHT_ORDER:
		GPIO.setup(light, GPIO.OUT)
	# Set Up to catch interrupt and turn out lights
	signal.signal(signal.SIGINT, exit)
	# Chase
	i = -1
	num_lights = len(LIGHT_ORDER)
	while True:
		prev = i
		i = (i + 1) % num_lights
		print "On: %d, Off: %d" % (i, prev)
		GPIO.output(LIGHT_ORDER[prev], GPIO.LOW)
		GPIO.output(LIGHT_ORDER[i], GPIO.HIGH)
		time.sleep(DELAY)

if __name__ == "__main__":
	main()