ZMK Keyboard for Cornix

ZMK board definitions and shields for the Cornix split ergonomic keyboard.

Documentation: English / 简体中文 · 简体中文 README · 日本語 README (AI-generated)

Current board release: v3.0.0

ZMK baseline: main with Zephyr 4.1

What is included

• cornix_left//zmk — left half for a standard split build
• cornix_right//zmk — right peripheral half
• cornix_ph_left//zmk — left peripheral half for a dongle build
• cornix_dongle_adapter — central dongle matrix and Bluetooth role
• cornix_dongle_eyelash — optional display hardware overlay
• cornix_indicator — production-ready RGB battery and connection indicators

Cornix uses a compact 3×6 column-staggered layout with three thumb keys per half. The hardware supports USB-C, Bluetooth, Kailh Choc V2 hot-swap sockets, and 10°, 18°, or 25° tenting.

Zephyr 4.1 requirements

Always use qualified ZMK board names such as nice_nano//zmk. The unqualified nice_nano target may select CONFIG_SETTINGS_NONE=y, discard the Bluetooth identity after reboot, and break existing split bonds.

For every nice!nano dongle or reset build, verify the final .config contains:

CONFIG_NVS=y
CONFIG_SETTINGS_NVS=y

It must not contain CONFIG_SETTINGS_NONE=y.

Build targets

Standard split:

include:
  - board: cornix_left//zmk
    artifact-name: cornix_left

  - board: cornix_right//zmk
    artifact-name: cornix_right

  - board: cornix_right//zmk
    shield: settings_reset
    artifact-name: cornix_reset

Dongle integration:

include:
  - board: nice_nano//zmk
    shield: cornix_dongle_adapter cornix_dongle_eyelash dongle_display
    snippet: studio-rpc-usb-uart
    artifact-name: cornix_dongle

  - board: cornix_ph_left//zmk
    artifact-name: cornix_left_for_dongle

  - board: cornix_right//zmk
    artifact-name: cornix_right

  - board: nice_nano//zmk
    shield: settings_reset
    artifact-name: dongle_reset

Use cornix_dongle_eyelash only when the dongle board does not already expose zephyr,display. The dongle_display module supplies the display widgets.

RGB indicators

Version 3.0.0 makes the optional cornix_indicator shield production-ready. It uses zmk-rgbled-widget to show battery and split-connection state.

The shield sets CONFIG_RGBLED_WIDGET_EXT_POWER_TIMEOUT_MS=1000. When no animation or static indicator remains active, the WS2812 power rail is turned off after 1000 ms to reduce idle consumption. LEDs that remain illuminated still consume power. RGB is opt-in and is not enabled in the default v3.0.0 release artifacts.

Flashing and recovery

1. Flash the matching settings-reset UF2 to every role whose bonds must be cleared.
2. Flash the left, right, and optional dongle UF2 files to their matching devices.
3. Reset both halves together and then reconnect the host.

Cornix has used the no-SoftDevice flash layout since v2.3. For older firmware, stock RMK interoperability, or a board that no longer enters UF2 mode, follow the bootloader recovery guide. Do not mix firmware roles or flash layouts without resetting the affected devices.

Documentation and support

• English installation guide
• 中文安装指南
• ZMK documentation
• Issue tracker
• RMK firmware project