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
RP2040 Bento
The RP2040 Bento, a relatively low profile breakout board without a USB connector, has been open-sourced by hainguyenac.
Stampy controller
An RP2040-based controller for handwiring keyboards: Stampy by Keebio.
Rhytm game controller
This controller by OmnisaiRen features mechanical switches, encoders, and comes with a detailed devlog.
Tiny2040 controller
Tiny 2040 is another RP2040-based development board, this time by Pimoroni.
Solder Party RP2350 Stamp & Stamp XL
Solder Party is expanding their Stamp line with new controllers: the RP2350 Stamp and Stamp XL are devboards with up to 48 GPIO pins.