The Arduino Uno CH340 Diagnostic Tool is a simple yet effective sketch designed to help you diagnose boot, reset, and serial communication issues on CH340G-based Arduino Uno boards. This tool is ...

The project illustrates an old Arduino USB board being hacked by finding the right pins and stringing a capacitor between the serial connector and the reset line.

While the Arduino family of boards connect to your computer using a USB virtual serial port, the ATmega ones have an actual serial connection on-board.