HMI/GUI done in Python using Opengl for graphics is used to interface to modified Simen Grbl CNC code on an Arduino over USB. Operating System Notes: Currently runs well in Linux with Ubuntu and Python2.5. Also in process it now runs in Windows XP 32bit with Python2.7 but comms need to be improved to run faster and gcode files only partial open. Change usbport to ex. COM3 when running windows.