This project began as a simple USB-to-UART adapter and developed into a reusable programmer for ESP32 boards and other embedded targets.

The design provides:

USB-C connectivity

CP2102N USB-to-UART conversion

3.3 V UART TX and RX

DTR and RTS programming-control signals

TX and RX activity indicators

5 V access for the target board

ESD protection on the exposed USB-C signals

A compact 2 × 3 programming header

The main engineering work was not only placing the CP2102N on a PCB. It involved checking the USB-C contact arrangement, protecting external lines, routing the USB differential pair, managing target power, configuring the CP2102N GPIO functions and verifying the assembled board on Windows.