Lighting Configuration
See the Lighting feature page for an overview of the available lighting systems in ZMK.
RGB Underglow
See the RGB underglow section in the Lighting feature page for more details, and hardware integration page for adding underglow support to a board.
See Configuration Overview for instructions on how to change these settings.
Kconfig
RGB underglow depends on Zephyr's LED strip driver, which provides additional Kconfig options.
Definition file: zmk/app/Kconfig
| Config | Type | Description | Default |
|---|---|---|---|
CONFIG_ZMK_RGB_UNDERGLOW | bool | Enable RGB underglow | n |
CONFIG_ZMK_RGB_UNDERGLOW_EXT_POWER | bool | Underglow toggling also controls external power | y |
CONFIG_ZMK_RGB_UNDERGLOW_AUTO_OFF_IDLE | bool | Turn off RGB underglow when keyboard goes into idle state | n |
CONFIG_ZMK_RGB_UNDERGLOW_AUTO_OFF_USB | bool | Turn off RGB underglow when USB is disconnected | n |
CONFIG_ZMK_RGB_UNDERGLOW_HUE_STEP | int | Hue step in degrees (0-359) used by RGB actions | 10 |
CONFIG_ZMK_RGB_UNDERGLOW_SAT_STEP | int | Saturation step in percent used by RGB actions | 10 |
CONFIG_ZMK_RGB_UNDERGLOW_BRT_STEP | int | Brightness step in percent used by RGB actions | 10 |
CONFIG_ZMK_RGB_UNDERGLOW_HUE_START | int | Default hue in degrees (0-359) | 0 |
CONFIG_ZMK_RGB_UNDERGLOW_SAT_START | int | Default saturation percent (0-100) | 100 |
CONFIG_ZMK_RGB_UNDERGLOW_BRT_START | int | Default brightness in percent (0-100) | 100 |
CONFIG_ZMK_RGB_UNDERGLOW_SPD_START | int | Default effect speed (1-5) | 3 |
CONFIG_ZMK_RGB_UNDERGLOW_EFF_START | int | Default effect index from the effect list (see below) | 0 |
CONFIG_ZMK_RGB_UNDERGLOW_ON_START | bool | Default on state | y |
CONFIG_ZMK_RGB_UNDERGLOW_BRT_MIN | int | Minimum brightness in percent (0-100) | 0 |
CONFIG_ZMK_RGB_UNDERGLOW_BRT_MAX | int | Maximum brightness in percent (0-100) | 100 |
Values for CONFIG_ZMK_RGB_UNDERGLOW_EFF_START:
| Value | Effect |
|---|---|
| 0 | Solid color |
| 1 | Breathe |
| 2 | Spectrum |
| 3 | Swirl |
The *_START settings only determine the initial underglow state. Any changes you make with the underglow behavior are saved to flash after a one minute delay and will be used after that.
Devicetree
ZMK does not have any Devicetree properties of its own. See the Devicetree bindings for Zephyr's LED strip drivers.
See the RGB underglow hardware integration page for examples of the properties that must be set to enable underglow.
Backlight
See the backlight section in Lighting feature page for more details, and hardware integration page for adding backlight support to a board.
See Configuration Overview for instructions on how to change these settings.
Kconfig
Definition file: zmk/app/Kconfig
| Option | Type | Description | Default |
|---|---|---|---|
CONFIG_ZMK_BACKLIGHT | bool | Enables LED backlight | n |
CONFIG_ZMK_BACKLIGHT_BRT_STEP | int | Brightness step in percent | 20 |
CONFIG_ZMK_BACKLIGHT_BRT_START | int | Default brightness in percent | 40 |
CONFIG_ZMK_BACKLIGHT_ON_START | bool | Default backlight state | y |
CONFIG_ZMK_BACKLIGHT_AUTO_OFF_IDLE | bool | Turn off backlight when keyboard goes into idle state | n |
CONFIG_ZMK_BACKLIGHT_AUTO_OFF_USB | bool | Turn off backlight when USB is disconnected | n |
The *_START settings only determine the initial backlight state. Any changes you make with the backlight behavior are saved to flash after a one minute delay and will be used after that.
Devicetree
Applies to: /chosen node
| Property | Type | Description |
|---|---|---|
zmk,backlight | path | The node for the backlight LED driver to use |
See the Zephyr devicetree bindings for LED drivers:
See the backlight hardware integration page for examples of the properties that must be set to enable backlighting.