An ultra-low profile Chiffre: Le Oeuf

I recently acquired some Kailh PG1425 (“X Switches”) to experiment with. As my first foray into ultra-low profile, I designed a riff on the popular Le Chiffre design.

This keyboard is ridiculously thin, measuring only 1.05 cm at the thickest point, and quite comfortable to type on.

The open-source design is available on GitHub.

I originally picked up these switches for a different project, but ultimately decided that PG1316S was a better candidate for that one and needed to find something to do with these. In lieu of any other ideas, I decided to draw from the Chiffre. Since only 1u caps are available for the X switch, I replaced the 1.25u+2u thumbs with 3x1u.

As before, I wanted this board to have support for wired and wireless builds. However, to keep it ultra-thin, I chose a Xiao footprint over the Pro Micro due to its support to be mounted SMT-style. As it has less IO, this meant I had to use a shift register to drive the matrix. Fortunately, ZMK made this super easy.

Though this project started out as a mere experiment, Le Oeuf has turned out to be one of my favorite boards to type on. It has replaced the tented split board that I have been dailying for work. As an added bonus, it is ultra-portable.

The community has shown a lot of interest in this board, and as a result a redesign using PG1316S is in development. This version will also feature a custom aluminum case for a more premium look and feel. More updates soon!