r4lv/zmk-config

Keyboard Firmware for Corne • QWERTZ • macOS • ZMK

Features

• QWERTZ. This layout is intended to be used with macOS' German keyboard layout (Deutsch > Deutsch or Deutsch > ABC — QWERTZ)
• mirrored symbols. Many symbols in the sun layer, many symbols are mirrored between the left and the right hand, like the braces []<>(){}, the slashes \/, and _- ;, !?.
• numblock. The moon layer features a numblock for the left hand, with . and , nearby. The shifted numbers 3, 4 and 7 press the cmd modifier as well, so in order to e.g. send cmd shift 7 (line comment in VS Code), you can press moon shift 7.
• screen brightness. The two (native) brightness control keys on the eclipse layer can also control external screen brightness, e.g. using Lunar.
• hyper. Many keys on the eclipse layer are mapped to the HYPER modifier (⇧⌃⌥⌘), symbolized by the orbit symbol. Those keys can be mapped to global shortcuts.
  • the keyboard shortcuts on the right side, for iTerm, Alfred and 1Password are directly mapped in those apps as hotkeys.
  • the keyboard shortcuts on the left side, for VS Code, VNC Viewer, and the Browser are mapped with Alfred to open/activate the respective app.
• magic shift. The magic shift key on the base layer behaves like
  • a regular RSHIFT when held,
  • a sticky RSHIFT when tapped (to capitalize the next letter), and
  • like &caps_word when double-tapped (to capitalize the next word).
• mouse replacement. Scoot can be used for mouse movement with the keyboard (using hyper I and hyper U on the eclipse layer)
• non-dead backtick. The backtick on the German macOS keyboard layout is a dead key, which messes up some text input fields. The upper left key on the sun layer actually sends shift alt numblock-7, which does nothing on its own, but that is a free slot on the German keyboard layout which can be remapped using Ukelele, when creating a custom keyboard layout. Note that a non-dead backtick can also be accessed with ctrl shift grave on the standard macOS layout, but that is interpreted as keyboard shortcut by many apps using non-standard input fields and thus does NOT send the backtick character as expected.
• emoji. The upper left key on the moon layer sends the globe E keyboard shortcut, which opens the emoji picker on newer versions of macOS. Older versions required ctrl cmd space.
• soft off. By holding the keys R T Z U for three seconds, the keyboard will go into soft off mode, which consumes very little power. Press both reset buttons to wake it up again.
• owl. The owl on both the keymap preview above, and the keyboard itself is custom drawn and one of the most useful features of the keyboard.

German QWERTZ on macOS

While most keyboards send the US keycodes to the operating system, even if the keycaps printed on the keyboard are in a different language, it is the operating system's job to map the keycodes to the characters which will appear on the screen, depending on the selected input source.

To simplify the configuration in the ZMK keymap file, the mapping between the desired (German) characters and the (US) keycodes is defined in de-mac/de-mac.yaml. It is used to generate the keys_de.h mapping which provides DE_Y, DE_SZ etc for corne.keymap, and the correct symbols for keymap-drawer.

usage

Use just to run the recipes in justfile:

just       # list recipes
just draw  # update cheatsheet/corne.png

just build # build zmk firmware with Docker

Make sure to check the setup-zephyr-sdk and update recipes in the justfile for the initial setup to build the firmware locally.

macOS input sources

The following input sources should be set up in System Preferences > Keyboard > Input Sources:

• Deutsch → Deutsch (or ABC — QWERTZ)
• Andere → Unicode Hex-Eingabe (no unicode symbols in the keymap for now)

Use ctrl+space to toggle between the input sources.

macOS keyboard shortcuts

fn / globe key

The Apple Magic Keyboard A1644 has an fn key, while the newer 2nd generation keyboards (A2449, A2450) have 🌐 fn printed on it.

The fn key is used to input:

• fn ←: HOME ↖
• fn →: END ↘
• fn ↑: PG_UP ⇞
• fn ↓: PG_DN ⇟
• fn ↵: KP_ENTER/keypad_enter ⌤, "Enter" (macOS calls the normal ↵ key "Return")
• fn ⌫: DEL ⌦, "forward delete" (macOS calls ⌫/BACKSPACE "Delete", and ⌦/DELETE "Forward Delete")

and additionally:

• the F-keys F1-F12, which would otherwise control the screen brightness, volume, media playback, etc
• accessibility, with fn ctrl F..

Some apps use the globe-key as shortcuts, e.g.:

• 🌐 E: Bearbeiten > Emoji & Symbole
• 🌐 F: Darstellung > Vollbildmodus

auto-align keymap

The bindings = <...> statements in the corne.keymap are traditionally formatted to visually match the keys on the hardware keyboard. A small helper tool, align.py is provided to automatically corrent the alignment.

dependencies

• python 3.6+, ruamel.yaml for processing templates
• keymap-drawer for generating keymap SVG (installed with pipx)
• bun/sass for compiling stylesheets
• resvg for converting keymap SVG to PNG
• just instead of make
• entr for re-building on file changes