RGB Underglow Configuration
See the RGB Underglow feature page for more details, including instructions 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 feature page for examples of the properties that must be set to enable underglow.