Adafruit CP2104 Friend - USB to Serial Converter

The Adafruit CP2104 Friend is a USB-to-serial converter breakout featuring the Silicon Labs CP2104 chip with Micro USB. It provides reliable serial communication at up to 2 Mbps, making it ideal for uploading firmware to Arduino, ESP8266, ESP32, and other microcontrollers that use an FTDI-style serial header.

The board is configured to match the standard FTDI cable pinout, with 5V power on the power pin and 3.3V signal levels (5V-compliant). It includes auto-reset circuitry for Arduino/ATmega328 boards, so you can upload code without manually pressing the reset button. RX/TX LEDs blink during data transfer for easy debugging.

Key Features

• CP2104 Chip – Up to 2 Mbps transfer speed with one-time-programmable settings memory
• Micro USB Connector – Standard USB connection
• FTDI-Compatible Pinout – Drop-in replacement for FTDI cables
• Auto-Reset – Works with Arduino/ATmega328 for one-click uploads
• 3.3V Signal Levels – 5V-compliant, works with both 3.3V and 5V systems
• RX/TX LEDs – Visual data transfer indicators
• Full Modem Control Pins – DTR, RTS, RI, DSR, and more on side pads

Also Available

• CP2102N Friend – Successor with USB-C and 3 Mbps speed

Driver Support

• Linux – No driver required (built into kernel)
• Windows – Automatic driver installation via Windows Update
• macOS – Driver available from Silicon Labs

Ideal For

• Uploading firmware to Arduino, ESP8266, ESP32, and other FTDI-port microcontrollers
• Serial debugging and data monitoring

Package Contents

• 1× Adafruit CP2104 Friend breakout (assembled and tested)
• 1× Right-angle socket header
• 1× Male header strip