I've recently finished building my first CNC machine. I'm using an Arduino uno rev3 as my controll board with knock-off 6600 motor drivers. I've verified that my laptop can communicate with the Arduino. Downloaded and installed Arduino, UGS, Java and Candle software. Problem: Neither UGS or Candle will connect to the machine. Firmware: GRBL, COM3, and Baud set to 115200. I am a woodworker not an electrician. Don't know the difference between an electrode and a diode. Any help will be greatly appreciated.