Keyboard Builders' Digest / Tips & Tricks
Seeeduino Xiao RP2040
Another RP2040-based controller with relatively small form factor: Seeeduino Xiao RP2040.
Published April 24, 2022
The Seeduino Xiao RP2040 was brought to my attention by MReavley's Slice36 project, and the BLE version was used on filibustercrankcase's Hummingbird too.
This nice little controller board is another in the ever-growing sea of development boards sporting the RP2040 chip.
Product page: this way.
Relatively cheap ($5.4 atm) – compared not just to other Xiao boards but also to other controllers in general.
The form factor is about 1u (21 x 17.5mm) so it's really easy to fit into pretty much any layout. This parameter makes it a good alternative to other small controllers like the Tiny2040, the RP2040-Zero or the RP2040 Stamp.
The number of GPIO pins (11) may scare you off at first sight, but it's more than enough for splits (in theory up to 30 keys per half) even with a basic matrix.
However, and I just learned this recently, with a "real" duplex matrix (bidirectional scan) you can control up to 60 keys with this tiny board. This makes the Seeeduino Xiao RP2040 suitable for driving a 60%-ish keyboard and huge splits alike.
(To be able to benefit from the duplex matrix, at least at the moment, you have to rewrite your custom matrix scanning algorithm for most firmware I guess, except if you use PRK, where this feature is already implemented.)
Published on Sun 24th Apr 2022. Featured in KBD #75 (source).
Related
Raspberry Pi Pico & RP2040
Thoughts on the Raspberry Pi Pico, a review, plus the Sparkfun and Adafruit boards using the same RP2040 chip.
Arduino UNO Mini
The UNO is not your typical keyboard controller, but the anniversary edition is actually only 34.2mm x 26.7mm. Hmmm.
Technoblogy RP2040
A minimal controller sporting a RP2040 chip with all the 30 GPIO pins broken out – designed by Technoblogy.
Free prototype PCBs from Seeed
Seeed Studio is running a sponsorship campaign of the Seeed Fusion Assembly service offering free PCB prototypes for DIY keyboard projects with a XIAO RP2040 controller included.
BluePhage Express
BluePhage Express: a Bluetooth controller for use with CircuitPython/KMK, QMK, and ZMK by SouthPawEngineer.