Keyboard Builders' Digest / Projects
Charlieflex keyboard
Chad Transtrum's nice unibody split with encoder: the Charlieflex.
Published June 10, 2025
The 30-32 key Charlieflex is an open-source low-profile monoblock split keyboard by Chad Transtrum. This wireless-first design features an encoder, some splay, and Xiao footprint.
I haven't had a non-split ergonomic keyboard before, so I thought I'd give one a try, but none of the existing boards had what I wanted. Hence: the Charlieflex – Chad.
The keyboard uses a Xiao microprocessor and ZMK, so it can be built for wireless with the XIAO BLE, or wired with the XIAO RP2040.
Features
- 30-32 keys (5x3+2-ish)
- low-pro Choc, hotswap
- XIAO footprint (e.g. BLE or RP2040)
- 3D-printed case
- encoder
- ZMK
3D files are included for the case, which comes in variations for one or two thumb keys for each hand. The LED light on the controller is surfaced to the top of the case where it serves as a status light for battery, Bluetooth, and layers.
Resources
The design was created in ergogen – Gerbers, KiCAD and ergogen yaml files are available at:
Published on Tue 10th Jun 2025. Featured in KBD #192.
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