Atreus trackpoint

atreus

QMK firmware for my Keyboardio Atreus + PS/2 TrackPoint mod.

The original firmware source was lost. This repo was rebuilt from the running keyboard:

• dump/atreus-flash.hex was read off the ATmega32U4 over Caterina/avr109.
• The QMK keymap was decoded from the dump and turned back into source under keyboards/atreus_trackpoint/.
• The trackpoint daughterboard schematic was copied in from KiCad.

If you're future-me opening this cold: start with docs/DECODING.md (how the keymap was recovered) and docs/HARDWARE.md (what's on the PCBs).

Hardware

• Keyboardio Atreus, ATmega32U4, Caterina bootloader
• Custom trackpoint daughterboard (KiCad files in hardware/, gerbers in hardware/gerbers/) with:
  • IBM-style PS/2 TrackPoint module
  • 5× WS2811-driven indicator LEDs
• 3D-printed trackpoint holder (hardware/3d-printed/atreus trackpoint holder v*.stl). Iterated through 8 versions in Jan 2021 — v8 is the last, presumably the keeper. The originating CAD (likely Fusion 360) was not recovered.

Layout

5 layers, all built on the standard 4×12 Atreus matrix:

Right-thumb keys are mod-tap:

• RCTL_T(KC_QUOT) — tap for ', hold for Right-Ctrl
• RALT_T(KC_MINS) — tap for -, hold for Right-Alt

Trackpoint mouse buttons are at matrix positions [2,5] and [2,6] — the center of the third row, wired through the matrix as KC_BTN1 / KC_BTN2.

See keyboards/atreus_trackpoint/keymaps/default/keymap.c for the full keymap.

Building

This repo contains only the custom keyboard folder. Drop it into a QMK checkout to build:

# 1. Get QMK
git clone https://github.com/qmk/qmk_firmware.git
cd qmk_firmware
make git-submodule        # pulls chibios, lufa, etc.

# 2. Link in this keyboard
ln -s ~/git/atreus/keyboards/atreus_trackpoint keyboards/atreus_trackpoint

# 3. Build
qmk compile -kb atreus_trackpoint -km default
# (output: atreus_trackpoint_default.hex in the repo root)

Before flashing a fresh build, confirm the trackpoint pins in keyboards/atreus_trackpoint/config.h are correct. They were guessed, not recovered. See docs/HARDWARE.md § "How to verify the pins".

If a new QMK release renamed something and the build breaks, the original firmware was built around early-2021 QMK — pin to a commit from that window and port forward in small steps.

Flashing

# Restore the captured backup
./flash.sh

# Or flash a fresh build
./flash.sh path/to/atreus_trackpoint_default.hex

To enter bootloader mode: hold Fn+Esc if the binding survived in your build, otherwise press the reset button on the bottom of the keyboard — it's accessible through a small hole in the bottom plate, poke it with a paperclip.

Layout of this repo

.
├── README.md
├── flash.sh                          # one-command flash helper
├── dump/
│   ├── atreus-flash.hex              # working firmware backup (re-flashable)
│   └── atreus-flash.bin              # raw binary, same content
├── docs/
│   ├── DECODING.md                   # how the keymap was recovered from the dump
│   └── HARDWARE.md                   # schematic notes, pin assignments, gotchas
├── hardware/
│   ├── atreus_trackpoint.{sch,kicad_pcb,pro,net,lib}
│   ├── 3d-printed/                   # printable STLs (v1-v8) of trackpoint holder
│   └── gerbers/                      # PCB fab files
├── keyboards/
│   └── atreus_trackpoint/            # QMK keyboard (symlink into qmk_firmware/keyboards)
│       ├── atreus_trackpoint.{c,h}
│       ├── config.h                  # matrix + trackpoint pin defs (TODOs!)
│       ├── rules.mk
│       ├── info.json
│       └── keymaps/default/
│           ├── keymap.c              # 5-layer keymap
│           └── rules.mk
└── tools/
    └── decode_keymap.py              # the decoder used on the dump