KeyModule

roamyboard, aka Pants Keyboard

A keyboard you wear on your legs, so you can type while you walk. Each half is a row of 3D-printed modules on a strap: key modules that click together at an angle, so the half curves around a thigh, an MCU module with a nice!nano, a battery and a display, and a terminator module at the far end. It runs ZMK over Bluetooth, and the right half's display has a built-in PDA.

Photos, the build and more: roamyboard.nevyn.dev. There you'll find the assembly guide, the layout, the PDA manual, and a page to order one.

But why‽ Because I think so much better when I'm moving. So I want to code while I move. So I need an input method that works while I'm moving. The original idea was to literally sew it into pants, but that's too impractical; now it's a strap you put on top of your pants.

I will also need a wearable computer and head mounted display to go with this setup, but that's for later.

Made by Nevyn Bengtsson 2012-2026 (this is not the first iteration 😅).

What's in here

This repo is also an Obsidian vault, which is why it has wiki syntax here and there.

• case/: the case. case/roamy-v4 is the current model, in Cadova (Swift): swift run there writes the printable 3MF files. Notes in Case design and Harness design. roamy-v3.py is the old CadQuery model.
• electronics/: the KiCad project for the key module board, and Electronics with the bus and the joint.
• zmk/: the firmware, ZMK plus a driver for the key modules' shift register chain. Firmware covers building, flashing over USB, updating over Bluetooth with roamy-ota or a phone, and Logging reading both halves' logs over Bluetooth with roamy-log; Layout covers the keymap.
• docs/: the website at roamyboard.nevyn.dev and the reference docs; docs/index.md lists them.
• Build Diary: what happened when.
• firmware/: the stock Lily58 firmware images from before the roamyboard had its own.

Inspiration

The construction started from ScottoChoczard, a hand-wired, PCB-less split that doesn't have to be flat, and the layout from the Lily58, which is wireless on a nice!nano with a conventional four-row layout. Since then it got its own PCBs and modules. More in Inspiration.