app.py

import RPi.GPIO as GPIO
import time
import subprocess
import threading

GPIO.setmode(GPIO.BCM);

GPIO.setup(18, GPIO.IN, pull_up_down=GPIO.PUD_UP);
GPIO.setup(2, GPIO.OUT);
# red led (top to bottom, 1-4 on physical device)
GPIO.setup(17, GPIO.OUT); # 4
GPIO.setup(27, GPIO.OUT); # 1
GPIO.setup(22, GPIO.OUT); # 2
GPIO.setup(23, GPIO.OUT); # 3

GPIO.output(2,GPIO.LOW)

blinking = False
ready = False

def blink():
	if blinking == False:
		GPIO.output(2,GPIO.LOW)
		time.sleep(1)
		return 	blink()
	GPIO.output(2,GPIO.LOW)
	time.sleep(1)
	GPIO.output(2,GPIO.HIGH)
	time.sleep(1)
	return blink()


def setupCommand(arr, ledPosition):
	print("setting up thread" + str(ledPosition))
	cmdThread = threading.Thread(name='command thread ' + str(ledPosition), target=execCommand, args=[arr, ledPosition])
	cmdThread.start()
	return cmdThread


def execCommand(arr,ledPosition):
	result = subprocess.check_output(arr)
	ret = True
	if result.strip() == "1" : 
		ret = False
		GPIO.output(ledPosition, GPIO.HIGH)
	time.sleep(0.22)
	print("result is:" + result.strip())
	return ret


led = threading.Thread(name='non-block', target=blink)
led.start()

while True:
	input_state = GPIO.input(18)
	blinking = False
	if input_state == False:
		if ready == True:
			print("start")
			ready = False
			blinking = True	
			GPIO.output(17,GPIO.LOW)
			GPIO.output(27,GPIO.LOW)
			GPIO.output(22,GPIO.LOW)
			GPIO.output(23,GPIO.LOW)
			# this just launches a shell script that handles the dd and checks. it was way easier to do it this way
			# for me. In the future I'll learn the IO in python. 
			t1 = setupCommand(['sudo', 'sh', '/home/pi/Development/sd-programmer/edd.sh', '/dev/sdb'], 27)
			t2 = setupCommand(['sudo', 'sh', '/home/pi/Development/sd-programmer/edd.sh', '/dev/sda'], 22)
			t3 = setupCommand(['sudo', 'sh', '/home/pi/Development/sd-programmer/edd.sh', '/dev/sdd'], 23)
			t4 = setupCommand(['sudo', 'sh', '/home/pi/Development/sd-programmer/edd.sh', '/dev/sdc'], 17)
			t1.join()
			t2.join()
			t3.join()
			t4.join()
			time.sleep(1)
			print("end of loop")
		else: 
			print("reset")
			ready = True
			GPIO.output(2,GPIO.LOW)
			GPIO.output(17,GPIO.HIGH)
			GPIO.output(27,GPIO.HIGH)
			GPIO.output(22,GPIO.HIGH)
			GPIO.output(23,GPIO.HIGH)
			time.sleep(1)