- Plenty powerful, low-cost, and makes for an excellent keeb driver chip
- Same size and form-factor as a Pro Micro breakout and nearly-identical pinout (this board has fewer analog pins, for example)
- 8 MB SPI FLASH chip for storing files and CircuitPython/MicroPython code storage.
- 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.
- Both Reset button and Bootloader select button for quick restarts.
A wild Kee Boar appears! It’s a shiny KB2040! An Arduino Pro Micro-shaped board for Keebs with RP2040. (#keeblife 4 evah) A lot of folks like using Adafruit parts for their Keeb builds – but with the ItsyBitsy not being pin-compatible with the Pro Micro pinout, it really wasn't very easy without some sort of adapter plate.
Now we’re seeing lots of people use CircuitPython for keebs, which is awesome! So why not try our hands at spinning up a pro-micro-compatible RP2040 board? The RP2040 is plenty powerful, low-cost, and makes for an excellent keeb driver chip.
We mixed together what we liked most about the SparkFun Pro Micro RP2040 (Qwiic / STEMMA QT I2C port on the end, so good!) and Elite-C (castellated pads & pins for D+ and D-) and our existing RP2040 boards (boot button can be used for user, 8MB QSPI flash, onboard NeoPixel, jumper for skipping the diode/fuse for high power RGB LEDs or USB hosting). 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.
Dimensions: 35.0mm x 17.8mm x 4.9mm / 1.4" x 0.7" x 0.2"
Weight: 2.8g / 0.1oz
18 GPIO on castellated/pin breakout pads. 2 GPIO on QT port that can be easily accessed for 5x15 keyboard layouts.
Four12 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
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.