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Lynx CAT

The Lynxware CAT is a set of split input devices built with mouse switches, open sourced by Ape_Devil of Lynxware.
Published January 25, 2024
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Stanislaw Kirpicnikow aka Ape_Devil's original cat project ("gamepad or shortcut-tool") was featured back in 2021, but he apparently made good progress with this pretty unique family of input devices, turning the CAT into a full-fledged split keyboard on steroids.

According to the author, the Lynxware CAT is a computer input device with different modules, which, together with the software provided, is a flexible system that accommodates the individual needs of any user.


The board sports mouse switches with 3D printed blank caps by the way, so it's for touch typers. In addition, it may act as a keyboard-mouse, similar to projects like the Lapa, Mouseky, Dichotomy, etc.

The best thing about the CATs? They are available both as open source for the more tech-savvy folks and as prebuilt products for the less DIY-minded.


  • 42-62 keys, columnar layout
  • mouse switches
  • BPI-Leaf-S3 controller (ESP32-S3)
  • 3D printed case
  • optional joystick, horizontal encoder, mouse, gyroscope

Replaceable modules make this tool very versatile: joystick, scroll wheel, mouse, gyroscope can be added on demand.

E.g. you can have a thumb module with a joystick or an all-key version with 11 buttons:


The finger modules come with 20 keys per half, or 17 if you'd like to swap the inner column for a roller encoder.


Other than that, additional parts like the mouse or gyroscope module, and exchangeable palm supports in different sizes make this system even more flexible:


On my set up I have a mouse in the right and a gyroscope in the left device. […] Gyro is there just to flex but keyboard and mouse in one is awesome, but I am obviously biased – Stanislaw.

The brain of the CAT is a Banana Pi, the low-powered BPI-Leaf-S3 development board with ESP32-S3 MCU.

As the software, the author made (and open sourced) LYNXapp, a Python based multilingual interface for setting up your CAT.


As of my understanding, the originally Arduino based firmware is written using PaltformIO (setup tutorial).

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Published on Thu 25th Jan 2024. Featured in KBD #152.


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