Wednesday, February 3, 2021


Carrier board for KMK experimenting

Three different KMK compatible MCU boards can be plugged into this board with a 12x4 key matrix of 6x6mm tactile switches.

The ESP32-S2 Saola board was the primary reason for this board. The micro USB connector is not the USB HID interface. Pins 19/20 are USB -/+. These are connected to the mini USB connector.

The narrower Raspberry Pi Pico fits inside the ESP32-S2 Saola footprint. You will need to modify the KMK as described here.

The Adafruit NRF52840 Express takes up the remaining space. The Adafruit NRF52840 also works over BLE if enabled (USB or BLE, not both).

All three MCU run the same KMK script. The only differences are the board pin definitions.

Gerber files on git.