Adafruit CH9328 UART to HID Keyboard Breakout

The Adafruit CH9328 UART to HID Keyboard Breakout enables you to emulate an HID keyboard using a standard UART serial connection. This chip acts as a programmed microcontroller that appears as an everyday HID keyboard, converting ASCII or 8-byte raw reports received via UART into keypresses. This breakout board is ideal for use with microcontrollers or single-board computers that lack native USB support, such as classic ATmega328 Uno, original ESP32, ESP8266, or even Raspberry Pi.

The breakout features a USB Type-C port for easy connection to computers, laptops, phones, or tablets, along with pads for 5V power and ground. It includes a UART RX receive input and a reset line to perform hard resets. The board offers four onboard mode switches to configure how input data is interpreted and sent as keystrokes.

Key features:

• Emulates USB HID keyboard from UART input
• Compatible with microcontrollers without native USB
• USB Type-C connector for easy connection
• Configurable operating modes via onboard switches
• Supports ASCII and raw 8-byte HID reports
• Includes support circuitry; soldering may not be necessary

Modes can be set using the onboard switches before powering the device, allowing options such as sending visible ASCII characters as-is, converting special keys like Enter, or sending raw HID reports for full control. Mode 3 is recommended for advanced usage with the CH9328 library.