Adafruit CH9328 UART to HID Keyboard Breakout

The CH9328 UART to HID Keyboard Breakout is a unique solution for emulating a keyboard even on microcontrollers or single-board computers without native USB support. This chip acts as a microcontroller that can convert ASCII or 8-byte raw reports, received over a standard UART serial connection, into keypresses, allowing you to add HID keyboard functionality to devices such as the ATmega328, original ESP32, ESP8266, or Raspberry Pi.

Key Features:

• Emulates HID Keyboard: Even microcontrollers without native USB support can emulate a keyboard by converting UART data into keypresses.
• USB Type-C Port: Easy connection to computers, laptops, and mobile devices.
• Solderless Setup: Use JST SH cables for a simple connection with 5V, Ground, and Data In.
• Mode Selection: Four on-board switches for different operating modes:
  • Mode 0: Sends visible ASCII characters as-is and converts 0x1B to "Enter".
  • Mode 1: Sends visible ASCII characters as-is with no conversions.
  • Mode 2: Sends visible ASCII characters as-is and converts 0x28 to "Enter".
  • Mode 3: Sends raw 8-byte HID reports for more control, ideal for custom keypresses and non-US keyboard emulation.
• Configurable Upload Speed: Switch #1 adjusts the upload speed (for most cases, this doesn't affect functionality).
• UART Input: Requires a 9600 baud 3V-logic signal for serial communication.
• 5V Power: Power the device via the 5V and Ground pads, with additional reset functionality for hard resets.

Applications:

• Emulate keyboards on devices without native USB support.
• Customize keypress behaviors or emulate non-US keyboards.
• Ideal for microcontrollers, Raspberry Pi, and single-board computers.
• Can send UART data via a USB-to-UART converter to emulate keyboard input on any device.

This chip provides an easy way to emulate a keyboard or other devices without needing native USB support, making it perfect for a wide range of applications. Whether you're working with microcontrollers or single-board computers, the CH9328 lets you send keypresses through UART data.