@ -24,7 +24,7 @@ There are various Kconfig options used to configure the backlight feature. These
| `CONFIG_ZMK_BACKLIGHT_BRT_STEP` | Brightness step in percent | 20 |
| `CONFIG_ZMK_BACKLIGHT_BRT_STEP` | Brightness step in percent | 20 |
| `CONFIG_ZMK_BACKLIGHT_BRT_START` | Default brightness in percent | 40 |
| `CONFIG_ZMK_BACKLIGHT_BRT_START` | Default brightness in percent | 40 |
| `CONFIG_ZMK_BACKLIGHT_ON_START` | Default backlight state | y |
| `CONFIG_ZMK_BACKLIGHT_ON_START` | Default backlight state | y |
| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_IDLE` | Turn off backlight when keyboard goes into idle state | y |
| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_IDLE` | Turn off backlight when keyboard goes into idle state | n |
| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_USB` | Turn off backlight when USB is disconnected | n |
| `CONFIG_ZMK_BACKLIGHT_AUTO_OFF_USB` | Turn off backlight when USB is disconnected | n |
## Adding Backlight to a Board
## Adding Backlight to a Board
@ -43,7 +43,7 @@ First, you need to enable PWM by adding the following lines to your `.overlay` f
};
};
```
```
The value `ch0-pin` represents the pin that controls the LEDs. To calculate the value to use, you need a bit of math. You need the hardware port and run it through a function.
The value `ch0-pin` represents the pin that controls the LEDs. With nRF52 boards, you can calculate the value to use in the following way: you need the hardware port and run it through a function.
**32 \* X + Y** = `<Pin number>` where X is first part of the hardware port "PX.01" and Y is the second part of the hardware port "P1.Y".
**32 \* X + Y** = `<Pin number>` where X is first part of the hardware port "PX.01" and Y is the second part of the hardware port "P1.Y".
For example, _P1.13_ would give you _32 \* 1 + 13_ = `<45>` and _P0.15_ would give you _32 \* 0 + 15_ = `<15>`.
For example, _P1.13_ would give you _32 \* 1 + 13_ = `<45>` and _P0.15_ would give you _32 \* 0 + 15_ = `<15>`.