{"id":20383066,"url":"https://github.com/headblockhead/slab-firmware","last_synced_at":"2026-03-12T02:33:06.233Z","repository":{"id":248309861,"uuid":"789932740","full_name":"headblockhead/slab-firmware","owner":"headblockhead","description":"Firmware for the core boards of the Slab Keyboard system.","archived":false,"fork":false,"pushed_at":"2025-04-15T16:56:35.000Z","size":244,"stargazers_count":2,"open_issues_count":0,"forks_count":1,"subscribers_count":1,"default_branch":"master","last_synced_at":"2025-10-07T13:59:17.089Z","etag":null,"topics":["c","keyboard","pico-sdk","slab-keyboard","tinyusb"],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"gpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/headblockhead.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2024-04-21T23:52:49.000Z","updated_at":"2025-03-16T19:36:48.000Z","dependencies_parsed_at":"2024-07-30T01:47:51.801Z","dependency_job_id":"860f7fde-c0b0-4a02-b851-35e09897318b","html_url":"https://github.com/headblockhead/slab-firmware","commit_stats":null,"previous_names":["headblockhead/slab-firmware"],"tags_count":1,"template":false,"template_full_name":null,"purl":"pkg:github/headblockhead/slab-firmware","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/headblockhead%2Fslab-firmware","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/headblockhead%2Fslab-firmware/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/headblockhead%2Fslab-firmware/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/headblockhead%2Fslab-firmware/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/headblockhead","download_url":"https://codeload.github.com/headblockhead/slab-firmware/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/headblockhead%2Fslab-firmware/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":30413104,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-03-12T00:40:14.898Z","status":"online","status_checked_at":"2026-03-12T02:00:07.260Z","response_time":114,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["c","keyboard","pico-sdk","slab-keyboard","tinyusb"],"created_at":"2024-11-15T02:20:10.827Z","updated_at":"2026-03-12T02:33:06.210Z","avatar_url":"https://github.com/headblockhead.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Slab Firmware\n\n[![Nix Flake](https://img.shields.io/badge/NIX%20FLAKE-5277C3.svg?logo=NixOS\u0026logoColor=white)](https://nixos.org) [![xc compatible](https://xcfile.dev/badge.svg)](https://xcfile.dev) \n\nThe full firmware and downloads for the [Slab keyboard project](https://github.com/headblockhead/slab).\n\nDownloads are in the releases section.\n\n## Building\n\nThis project uses [Nix](https://nixos.org), run `nix develop` for a development environment, and `nix build` to build the firmware.\n\n## Tasks\n\n\u003e [!IMPORTANT]\n\u003e You must be in the `nix develop` shell for these tasks to work!\n\n### upload\nDirectory: ./build\nRequires: build\n\nBuilds and uploads the firmware to the RP2040.\n\n```bash\nexport PICO_DIR=`findmnt -S LABEL=RPI-RP2 -o TARGET -fn`\ncp ./slab.uf2 $PICO_DIR\n```\n\n### upload-dbg\nDirectory: ./build\nRequires: build-dbg\n\nBuilds and uploads debug firmware to the RP2040.\n\n```bash\nexport PICO_DIR=`findmnt -S LABEL=RPI-RP2 -o TARGET -fn`\ncp ./slab.uf2 $PICO_DIR\n```\n\n### build\nDirectory: ./build\n\n```bash\ncmake -DCMAKE_BUILD_TYPE=Release ..\ncmake --build . -j $(nproc)\n```\n\n### build-dbg\nDirectory: ./build\n\nBuilds the keyboard firmware with development outputs.\n\n```bash\ncmake -DCMAKE_BUILD_TYPE=Debug .. \ncmake --build . -j $(nproc)\ncp compile_commands.json ../ # Copies the autocomplete information for ccls.\n```\n\n### clean\n\nDeletes the contents of the build directory.\n\n```bash\nrm -rf ./build\nmkdir build\n```\n\n### fetch-submodules\n\nFetches submodules if not already present.\n\n```bash\ngit submodule update --init --recursive\n```\n\n## Technical Details\n\n### Communication between devices\n\nDevices communicate using I²C, but not in the typical way of all devices sharing the same bus.\n\nFor each device, I²C bus 1 is set to act as a master that controlls all on-board slaves (OLED screens, etc.), and can control another connected keyboard slave.\nI²C bus 2 is set to act as a slave, controlled by the bus 1 (master) of another board.\n\nBoards are chained together, with each board's I²C bus 1 connected to the next board's I²C bus 2, in sequence.\n\n#### Packets\n\nPackets are made of 1 `packet_type` byte, followed by the appropriate amount of bytes for that `packet_type`.\n\n##### Packet types:\n- `COM_TYPE_ALIVE` is 0 bytes, and is sent continuously to allow boards to know if the board that is controlling them is still alive.\n- `COM_TYPE_ACCUMULATION_PACKET` is 11 bytes, and contains all the SQUIRREL data, to be accumulated as it travels through the keyboard from right to left.\n- `COM_TYPE_WANT_ACCUMULATION_STATUS` is 0 bytes and is sent continuously until `COM_TYPE_DONE_ACCUMULATING` is recieved as a response.\n- `COM_TYPE_NOT_DONE_ACCUMULATING` is 11 bytes, all ignored.\n- `COM_TYPE_DONE_ACCUMULATING` is 11 bytes, containing the SQUIRREL data, as accumulated, from the leftmost board.\n\n#### Sequence Diagram\n\n```mermaid\nsequenceDiagram\n    participant Board 1 (L)\n    participant Board 2\n    participant Board 3\n    participant Board 4\n    participant Board 5 (R)\n\n    # First communication.\n\n    activate Board 1 (L)\n\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_ACCUMULATION_PACKET\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_ACCUMULATION_PACKET\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_ACCUMULATION_PACKET\n    Board 2 -\u003e\u003e Board 1 (L): COM_TYPE_ACCUMULATION_PACKET\n\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 4 -\u003e\u003e Board 5 (R): COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 3 -\u003e\u003e Board 4: COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 2 -\u003e\u003e Board 3: COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 2 -\u003e\u003e Board 1 (L): COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 1 (L) -\u003e\u003e Board 2: COM_TYPE_DONE_ACCUMULATING\n    \n    activate Board 2\n\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 2 -\u003e\u003e Board 3: COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 3\n\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 3 -\u003e\u003e Board 4: COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 4\n\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 4 -\u003e\u003e Board 5 (R): COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 5 (R)\n\n    # Second communication.\n\n    deactivate Board 5 (R)\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_ACCUMULATION_PACKET\n    deactivate Board 4\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_ACCUMULATION_PACKET\n    deactivate Board 3\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_ACCUMULATION_PACKET\n    deactivate Board 2\n    Board 2 -\u003e\u003e Board 1 (L): COM_TYPE_ACCUMULATION_PACKET\n\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 4 -\u003e\u003e Board 5 (R): COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 3 -\u003e\u003e Board 4: COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 2 -\u003e\u003e Board 3: COM_TYPE_NOT_DONE_ACCUMULATING\n\n    Board 2 -\u003e\u003e Board 1 (L): COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 1 (L) -\u003e\u003e Board 2: COM_TYPE_DONE_ACCUMULATING\n    \n    activate Board 2\n\n    Board 3 -\u003e\u003e Board 2: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 2 -\u003e\u003e Board 3: COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 3\n\n    Board 4 -\u003e\u003e Board 3: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 3 -\u003e\u003e Board 4: COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 4\n\n    Board 5 (R) -\u003e\u003e Board 4: COM_TYPE_WANT_ACCUMULATION_STATUS\n    Board 4 -\u003e\u003e Board 5 (R): COM_TYPE_DONE_ACCUMULATING\n\n    activate Board 5 (R)\n\n    deactivate Board 2\n    deactivate Board 3\n    deactivate Board 4\n    deactivate Board 5 (R)\n    deactivate Board 1 (L)\n```\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fheadblockhead%2Fslab-firmware","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fheadblockhead%2Fslab-firmware","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fheadblockhead%2Fslab-firmware/lists"}