Pi Rover: send command and data byte to controller, http://goo.gl/tRcYrB

send.py

#!/usr/bin/python
#title           :send.py
#description     :Send command and data byte to motor controller.
#author          :helfrich
#================================================================

import serial
import sys

ser = serial.Serial('/dev/ttyUSB0', 19200, timeout = 1)

print(sys.argv[1])
ser.write(chr(int(sys.argv[1])))

if (len(sys.argv) > 2):
    print(sys.argv[2])
    ser.write(chr(int(sys.argv[2])))