forked from forks/qmk_firmware
122 lines
5.1 KiB
Markdown
122 lines
5.1 KiB
Markdown
# LED Indicators
|
|
|
|
?> LED indicators on split keyboards will require state information synced to the slave half (e.g. `#define SPLIT_LED_STATE_ENABLE`). See [data sync options](feature_split_keyboard.md#data-sync-options) for more details.
|
|
|
|
QMK provides methods to read 5 of the LEDs defined in the HID spec:
|
|
|
|
* Num Lock
|
|
* Caps Lock
|
|
* Scroll Lock
|
|
* Compose
|
|
* Kana
|
|
|
|
There are three ways to get the lock LED state:
|
|
* Configuration options in `config.h`
|
|
* Implement `led_update_*` function
|
|
* Call `led_t host_keyboard_led_state()`
|
|
|
|
!> The `host_keyboard_led_state()` may reflect an updated state before `led_update_user()` is called.
|
|
|
|
Two deprecated functions that provide the LED state as `uint8_t`:
|
|
|
|
* `uint8_t led_set_user(uint8_t usb_led)`
|
|
* `uint8_t host_keyboard_leds()`
|
|
|
|
## Configuration Options
|
|
|
|
To configure the indicators, `#define` these in your `config.h`:
|
|
|
|
|Define |Default |Description |
|
|
|---------------------|-------------|-------------------------------------------|
|
|
|`LED_NUM_LOCK_PIN` |*Not defined*|The pin that controls the `Num Lock` LED |
|
|
|`LED_CAPS_LOCK_PIN` |*Not defined*|The pin that controls the `Caps Lock` LED |
|
|
|`LED_SCROLL_LOCK_PIN`|*Not defined*|The pin that controls the `Scroll Lock` LED|
|
|
|`LED_COMPOSE_PIN` |*Not defined*|The pin that controls the `Compose` LED |
|
|
|`LED_KANA_PIN` |*Not defined*|The pin that controls the `Kana` LED |
|
|
|`LED_PIN_ON_STATE` |`1` |The state of the indicator pins when the LED is "on" - `1` for high, `0` for low|
|
|
|
|
Unless you are designing your own keyboard, you generally should not need to change the above config options.
|
|
|
|
## LED update function
|
|
|
|
When the configuration options do not provide enough flexibility, the following callbacks allow custom control of the LED behavior. These functions will be called when one of those 5 LEDs changes state:
|
|
|
|
* Keyboard/revision: `bool led_update_kb(led_t led_state)`
|
|
* Keymap: `bool led_update_user(led_t led_state)`
|
|
|
|
Both receives LED state as a struct parameter. Returning `true` in `led_update_user()` will allow the keyboard level code in `led_update_kb()` to run as well. Returning `false` will override the keyboard level code, depending on how the keyboard level function is set up.
|
|
|
|
?> This boolean return type of `led_update_user` allows for overriding keyboard LED controls, and is thus recommended over the void `led_set_user` function.
|
|
|
|
### Example of keyboard LED update implementation
|
|
|
|
This is a template indicator function that can be implemented on keyboard level code:
|
|
|
|
```c
|
|
bool led_update_kb(led_t led_state) {
|
|
bool res = led_update_user(led_state);
|
|
if(res) {
|
|
// gpio_write_pin sets the pin high for 1 and low for 0.
|
|
// In this example the pins are inverted, setting
|
|
// it low/0 turns it on, and high/1 turns the LED off.
|
|
// This behavior depends on whether the LED is between the pin
|
|
// and VCC or the pin and GND.
|
|
gpio_write_pin(B0, !led_state.num_lock);
|
|
gpio_write_pin(B1, !led_state.caps_lock);
|
|
gpio_write_pin(B2, !led_state.scroll_lock);
|
|
gpio_write_pin(B3, !led_state.compose);
|
|
gpio_write_pin(B4, !led_state.kana);
|
|
}
|
|
return res;
|
|
}
|
|
```
|
|
|
|
### Example of user LED update implementation
|
|
|
|
This is an incomplete example will play a sound if Caps Lock is turned on or off. It returns `true` to allow keyboard LED function to maintain their state.
|
|
|
|
```c
|
|
#ifdef AUDIO_ENABLE
|
|
float caps_on[][2] = SONG(CAPS_LOCK_ON_SOUND);
|
|
float caps_off[][2] = SONG(CAPS_LOCK_OFF_SOUND);
|
|
#endif
|
|
|
|
bool led_update_user(led_t led_state) {
|
|
#ifdef AUDIO_ENABLE
|
|
static uint8_t caps_state = 0;
|
|
if (caps_state != led_state.caps_lock) {
|
|
led_state.caps_lock ? PLAY_SONG(caps_on) : PLAY_SONG(caps_off);
|
|
caps_state = led_state.caps_lock;
|
|
}
|
|
#endif
|
|
return true;
|
|
}
|
|
```
|
|
|
|
## Host keyboard LED state
|
|
|
|
The `host_keyboard_led_state()` function will report the LED state returned from the host computer as `led_t`. This is useful for reading the LED state outside `led_update_*`. For example, you can get the boolean state of Caps Lock from the host with:
|
|
|
|
```c
|
|
bool caps = host_keyboard_led_state().caps_lock;
|
|
```
|
|
|
|
## `led_update_ports()`
|
|
|
|
This function writes the LED state to the actual hardware. Call it manually
|
|
from your `led_update_*()` callbacks to modify the handling of the standard
|
|
keyboard LEDs.
|
|
For example when repurposing a standard LED indicator as layer indicator.
|
|
|
|
## Setting Physical LED State
|
|
|
|
Some keyboard implementations provide convenient methods for setting the state of the physical LEDs.
|
|
|
|
### Ergodox Boards
|
|
|
|
The Ergodox implementations provide `ergodox_right_led_1`/`2`/`3_on`/`off()` to turn individual LEDs on or off, as well as `ergodox_right_led_on`/`off(uint8_t led)` to turn them on or off by their index.
|
|
|
|
In addition, it is possible to specify the brightness level of all LEDs with `ergodox_led_all_set(uint8_t n)`; of individual LEDs with `ergodox_right_led_1`/`2`/`3_set(uint8_t n)`; or by index with `ergodox_right_led_set(uint8_t led, uint8_t n)`.
|
|
|
|
Ergodox boards also define `LED_BRIGHTNESS_LO` for the lowest brightness and `LED_BRIGHTNESS_HI` for the highest brightness (which is the default).
|