The Adafruit CH9328 UART to HID Keyboard Breakout lets any microcontroller or single-board computer emulate a USB keyboard — even without native USB support. Simply send ASCII characters or raw HID reports over a 9600-baud serial connection, and the CH9328 converts them into real keypresses on the connected computer, laptop, or mobile device.

The breakout includes a USB Type-C port for easy plug-and-play connection to a host device, plus a JST SH connector for solderless wiring to your microcontroller. Four on-board DIP switches configure the operating mode before power-up.

Key Features

• UART to USB HID Keyboard – Converts serial data into standard USB keyboard keypresses
• USB Type-C Output – Plug directly into any computer, laptop, phone, or tablet
• 9600 Baud 3V UART Input – Works with hardware or software serial from any microcontroller or SBC
• 4 DIP Switches – Configure operating mode before power-up
• JST SH Connector – Solderless connection option (5V, GND, data in)
• 5V Power Output – Power your microcontroller from the USB host via the 5V and GND pads
• Reset Line – Hardware reset input for reliable operation

DIP Switch Modes

• Mode 0 (SW 2, 3, 4 ON) – ASCII characters sent as-is; 0x1B triggers Enter key
• Mode 1 (SW 2, 4 ON; SW 3 OFF) – ASCII characters sent as-is, no special key mapping
• Mode 2 (SW 2, 3 ON; SW 4 OFF) – ASCII characters sent as-is; 0x28 triggers Enter key
• Mode 3 (SW 3, 4 ON; SW 2 OFF) – Raw 8-byte HID reports for full control over keypresses, key holds, and non-US keyboard layouts

Ideal For

• Adding keyboard emulation to boards without native USB (ATmega328, ESP32, ESP8266)
• Automating keyboard input from a Raspberry Pi or other SBC
• Building custom macro keyboards or input devices
• Cross-device typing — have one computer type into another

Package Contents

• 1× Adafruit CH9328 UART to HID Keyboard Breakout