Officially supported microcontrollers

While most CircuitPython devices are great for hand wired keyboards, most keyboards are designed to accept a Pro Micro. The boards listed below either are, or can be adapted to that pinout to use common keyboards already on the market.

nice!nano

Features include

  • Pro Micro pinout
  • Both USB HID and Bluetooth support
  • Can do Bluetooth split keyboards with no wires at all
  • Has battery support including charging

Downsides

  • $25 USD per microcontroller at most retailers
  • Not enough space to run KMK without compiling

Pre-compiling KMK for nice!nano (or any other microcontroller with limited flash)

As the nice!nano has limited flash memory you’ll need to use a compiled KMK.

ItsyBitsy M4 Express

Features include

  • Affordable at $15 USD
  • Can run most features of KMK including RGB

Downsides

RP2040

Features include

  • Very affordable
  • Very powerful for the price

Downsides

  • Little support for keyboard kits

Adafruit ItsyBitsy nRF52840 Express

Features include

  • Both USB HID and Bluetooth support
  • More affordable than the nice!nano at only $18

Downsides

Other microcontrollers

What you’ll need to have at minimum

  • CircuitPython
  • 256KB of flash storage
  • HID over USB and/or Bluetooth.

Please keep in mind that KMK relies on CircuitPython’s ability to use Bluetooth Low Energy with any given controller.