The KB2040 is an Arduino Pro Micro-shaped board for Keebs with RP2040.

Adafruit mixed together what they liked most about the SparkFun Pro Micro RP2040, the Elite-C, and their existing RP2040 boards. We even got it to all fit on a 2-layer PCB with 7/7 routing – just needed to make the smallest caps and resistors 0402. 

With 20 GPIO available (18 on castellated pins, 2 on STEMMA QT port) you can easily make up to 100-keys matrices, or common 65% 5x15 layouts.

Board features:

• Same size and form-factor as a Pro Micro breakout and nearly-identical pinout (this board has fewer analog pins, for example)
• Measures 1.3" x 0.7" without headers soldered in
• RP2040 32-bit Cortex M0+ dual core running at ~125 MHz @ 3.3V logic and power. 264 KB RAM, No EEPROM. 12 MHz crystal for perfect timing.
• 8 MB SPI FLASH chip for storing files and CircuitPython/MicroPython code storage.
• 20 x GPIO pins with following capabilities:
  • 18 GPIO on castellated/pin breakout pads. 2 GPIO on QT port that can be easily accessed for 5x15 keyboard layouts.
  • Four 12 bit ADCs
  • Two I2C, Two SPI and two UART peripherals, we label one of for the 'main' interface in standard Pro Micro locations
  • 16 x PWM outputs - for servos, LEDs, etc
  • The 10 digital non-ADC GPIO are consecutive for maximum PIO compatibility
• RGB NeoPixel for colorful status indiction
• Classic green power LED
• Both Reset button and Bootloader select button for quick restarts. Bootloader button is also available as a generic GPIO input button.
• STEMMA QT connector on the end is compatible with the SparkFun Qwiic I2C connector, and can be used to plug and play I2C devices, or just as 2 extra GPIO pins.
• 3.3V regulator with 500mA peak current output
• RAW output, for powering NeoPixels or other 5V devices. Jumper on bottom lets you skip over the 500mA fuse, for up to 2A from USB ports.
• USB Type C connector lets you access built-in ROM USB bootloader and serial port debugging
• Extra D- and D+ breakouts for alternative USB connection options.