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Adafruit KB2040 Kee Boar

An RP2040 based development board by Adafruit, designed with keyboard builders in mind.
Published November 25, 2021

The first batch being sold out practically in a single day, these Adafruit Keeboars proved to be an instant success.

KB2040, Keeboar, Kee Boar, whatever. If you are not quite sure what I'm talking about, it's a brand new controller board by Adafruit, a Pro Micro alternative featuring the Raspberry RP2040 chip, and designed for keyboard enthusiasts.

I signed up to the notification a few days ago in the Adafruit store and the mail came yesterday at 18:00 (CET): "the Adafruit KB2040 is restocked and there are 235 units available".

Today, checking back at the same time, there are only 18 left. (As of writing this update, the item is out of stock, however, I was told it is restocked each day.)

Unlike Arduino's UNO Mini, Adafruit designed this board with keyboard builders in mind. If the KB(!)2040 codename or the "Keeboar" nick wouldn't make this clear, all the marketing materials refer to this one as a controller dedicated to keyboard building:

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 – Adafruit.

With dimensions identical to the original Pro Micro footprint (18x33mm), USB-C connector, 18+2 GPIO pins, castellated pads, and the RP2040 chip (datasheet) we now have a Pro Micro on steroids for $9.

Theoretically enough for a 100-key keyboard matrix, just like an "upgraded" Pro Micro, but with way more juice.

The RP2040's 32-bit Cortex M0+ dual cores running at 125 MHz, the 264 KB RAM and 8 MB SPI FLASH chip for storing files may seem an overkill but they come in handy when using CircuitPython and its more user-friendly workflow.

The code can be changed with any text editor which makes it super easy to update your keymap and customize the functions of your keyboard. No need to download any software, use online tools or setup a local development environment.

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.

The price? Well, $9 vs the Pi Pico's $5 for the Pro Micro footprint? You should decide if it's worth it.

Thanks to Phillip from Adafruit, one of these beasts is on its way to the HQ so hopefully I will be able to test it thoroughly in a few days.

Published on Thu 25th Nov 2021. Featured in KBD #54 (source).

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