CP2102 USB to TTL UART Converter Module

A computer's USB port and a microcontroller's TTL serial pins cannot talk directly - this module is the bridge, converting USB 2.0 into a standard TTL serial connection that shows up on a computer as an ordinary COM port. The CP2102 chip handles the protocol conversion entirely onboard, so no driver-level firmware writing is needed beyond installing the (widely available) CP2102 driver once.

Switchable 3.3V and 5V logic levels mean the same module works with both 3.3V boards like bare ESP8266/ESP32 modules and 5V boards like an Arduino Pro Mini, without needing a separate level-shifter or a different adapter per board voltage. A 640-byte transmit buffer keeps data flowing smoothly during larger firmware uploads rather than stalling on buffer underrun.

Common uses are flashing firmware to ESP8266/ESP32 boards and bare microcontrollers lacking onboard USB, serial debugging output during development, and general USB-to-serial bridging for any TTL-level device.