The M5Stack Unit CardKB2 is a compact, card-sized keyboard module designed for portable input and embedded applications.
It features 42 keys in a lightweight form factor, making it suitable for on-the-go use or integration into custom hardware projects. The unit is powered by an ESP32-C61HF4 microcontroller with built-in 2.4GHz Wi-Fi 6, enabling both wired and wireless communication options.
Pre-installed firmware supports four communication modes - I2C, UART, BLE HID, and ESP-NOW - allowing it to be used in a wide range of setups, from direct microcontroller input to wireless control interfaces. The board includes an HY2.0-4P expansion connector for easy integration with compatible systems, along with a USB-C port for power and firmware updates.
Additional features include an RGB LED for status indication, dedicated Reset and Boot buttons, and built-in input overvoltage protection to help safeguard the device during use.
Features
Powered by ESP32-C61HF4 with Wi-Fi 6 / BLE wireless communication support
Full keyboard input with support for multiple key combinations (single press, Sym, Fn)
Onboard RGB LED (XL-1615RGBC-RF) for keyboard status indication
