Multi-Board ZMK Config

🪸 Urchin	✖️ Crosses	🪶 Corne
34 keys (3x5+2)	36 keys (3x5+3)	42 keys (3x6+3)

My personal ZMK firmware configuration shared across some different keyboards. Features a unified logical layout with board-specific physical mappings.

Architecture

This project uses a modular architecture to share keymap logic across different keyboard layouts:

• config/base.dtsi: Core keymap logic (layers, combos, behaviors) for 34 logical keys
• Board-specific keymaps: Map the 34 logical keys to each keyboard's physical layout
  • urchin.keymap: 34 keys (direct mapping)
  • corne.keymap: 42 keys (34 logical + 8 edge keys)
  • crosses.keymap: 36 keys (34 logical + 2 thumb keys)

Features

• Home Row Mods: Inspired by urob's timeless layout
• Smart Combos: Essential actions (Esc, Enter, Cut/Copy/Paste) without extra keys
• Auto-Sentence: Automatic capitalization and period insertion
• Mouse Layer: Pointing device support with tap-toggle/hold-momentary behavior (board-dependent)
• Shared Configuration: DRY approach with default.conf for common settings

Layout

🪸 Urchin	✖️ Crosses	🪶 Corne

Setup

This project uses mise for tool management and just for commands.

1. Install mise: Follow instructions at mise.jdx.dev
2. Initialize environment:

   mise exec -- just init

Commands

All commands support multiple boards. Run with mise exec -- just <command> or just <command> if mise is activated.

Build Firmware

just build [board] [side]    # board: urchin (default), corne, crosses
                             # side: left, right, all (default)

Examples:

• just build → Build Urchin (both sides)
• just build corne left → Build Corne left side
• just build crosses all → Build Crosses (both sides)

Flash Firmware

just flash [board] [side]    # board: urchin, corne, crosses
                             # side: left, right

Examples:

• just flash corne right → Flash Corne right side

Generate Keymap Visualization

just draw [board]             # board: urchin, corne, crosses

Examples:

• just draw → Generate draw/urchin.svg
• just draw corne → Generate draw/corne.svg
• just draw all → Generate all boards

Other Commands

Command	Description
just clean	Clean build artifacts
just clean-all	Clean everything (workspace + venv)
just update	Update ZMK and dependencies
just check	Verify environment setup

Credits

• urob/zmk-config — Home-row mods and ZMK helpers
• caksoylar/keymap-drawer — Keymap visualization
• duckyb/urchin — Urchin keyboard design
• Good-Great-Grand-Wonderful/crosses — Crosses keyboard design
• foostan/crkbd — Corne keyboard design