how and why was that working, the modified circuit design. 8u2-burn.bat, to brun Arduino-usbserial-atmega8u2-Uno-Rev1-PID_0x0001-xiaolaba.hex to the chip, burn_arduino_com8.bat, to burn 328p.hex to ...

This repository provides a diagnostic sketch to help identify serial communication failures, bootloader instability, or USB-related execution issues in Arduino Uno clones that use the CH340G or CH340C ...