control 4-input H-Bridge via Raspberry Pi GPIO

hbridge1.py

#!/usr/bin/python

import RPi.GPIO as GPIO
import sys

GPIO.setmode(GPIO.BOARD)

K1 = 38 # G20
K2 = 7  # G4
K3 = 36 # G16
K4 = 40 # G21

GPIO.setwarnings(False)
GPIO.setup([K1, K2, K3, K4], GPIO.OUT, initial=GPIO.LOW)

GPIO.output(K1, False)
GPIO.output(K2, False)
GPIO.output(K3, False)
GPIO.output(K4, False)

if len(sys.argv) < 2:
	print "usage: %s [coast|forward|reverse|brake|brake2]" % (sys.argv[0],)
	raise SystemExit

if sys.argv[1] == 'coast':
	pass
elif sys.argv[1] == 'forward':
	GPIO.output(K1, True)
	GPIO.output(K4, True)
elif sys.argv[1] == 'reverse':
	GPIO.output(K3, True)
	GPIO.output(K2, True)
elif sys.argv[1] == 'brake':
	GPIO.output(K2, True)
	GPIO.output(K4, True)
elif sys.argv[1] == 'brake2':
	GPIO.output(K1, True)
	GPIO.output(K3, True)
else:
	print "unrecognized: %s" % (sys,argv[1],)