import serial,sys,time
serial = serial.Serial('/dev/ttyS0', 19200, timeout=1)

def check_conn():
	serial.write("G21\n")
	if serial.readline().strip()=="ok":
		print "Connected"
	else:
		sys.exit("Serial connection could not be established")

def send_line(line):
	print "Sending "+line
	serial.write(line)
	response = serial.readline()
	while not response:
		time.sleep(1)
		response = serial.readline()

def main():
	try:
		filename = sys.argv[1]
	except IndexError:
		print "Usage: serial_gcode filename"
		sys.exit
	try:
		g_code = open(filename, 'r').readlines()
	except IOError:
		print "An error occured opening the file "+filename
	check_conn()
	for line in g_code:
		send_line(line)


	
if __name__ == "__main__":
	main()