flipperzero-firmware/wiki/fw/api/API:LED.md
coreglitch 870fa8c7cd
[WIP] Core api (#134)
* add input debounce code from old fw

* exampl of input api

* change input API to get/release

* revert input API to read

* pointer instead of instance

* add input API description

* add display API

* rewrite display names

* migrate to valuemanager

* add links

* little changes

* add LED API

* add closing brakets

* add sound api

* change format

* Delete input.c

* Delete input.h

* change format
2020-09-26 01:51:54 +03:00

125 lines
3.2 KiB
Markdown

LED state describes by struct:
```C
typedef struct {
uint8_t red;
uint8_t green;
uint8_t blue;
} Rgb;
```
LED API provided by struct:
```C
typedef struct {
LayeredReducer* source; /// every app add its layer to set value, LayeredReducer<Rgb*>
Subscriber* updates; /// LED value changes Supscriber<Rgb*>
ValueMutex* state; /// LED state, ValueMutex<Rgb*>
} LedApi;
```
You can get API instance by calling `open_led`:
```C
/// Add new layer to LED:
inline LedApi* open_led(const char* name) {
return (LedApi*)furi_open(name);
}
```
Default system led is `/dev/led`.
Then add new layer to control LED by calling `add_led_layer`:
```C
inline ValueManager* add_led_layer(Rgb* layer, uint8_t priority) {
ValueManager* manager = register_valuemanager((void*)layer);
if(manager == NULL) return NULL;
if(!add_layered_reducer(manager, priority, layer_compose_default)) {
unregister_valuemanager(manager);
return NULL;
}
return manager;
}
```
For change led you can get display instance pointer by calling `take_led`, do something and commit your changes by calling `commit_led`. Or you can call `write_led`:
```C
/// return pointer in case off success, NULL otherwise
inline Rgb* take_led(ValueManager* led, uint32_t timeout) {
return (Rgb*)take_mutex(led->value, timeout);
}
inline void commit_led(ValueManager* led, Rgb* value) {
commit_valuemanager(led, value);
}
/// return true if success, false otherwise
inline bool write_led(ValueManager* led, Rgb* value, uint32_t timeout) {
return write_valuemanager(state, (void*)value, sizeof(Rgb), timeout);
}
```
To read current led state you should use `read_led` function:
```C
/// return true if success, false otherwise
inline bool read_led(ValueManager* led, Rgb* value, uint32_t timeout) {
return read_mutex(led->value, (void*)value, sizeof(Rgb), timeout);
}
```
Also you can subscribe to led state changes:
Use `subscribe_led_changes` to register your callback:
```C
/// return true if success, false otherwise
inline bool subscribe_led_changes(Subscriber* updates, void(*cb)(Rgb*, void*), void* ctx) {
return subscribe_pubsub(events, void(*)(void*, void*)(cb), ctx);
}
```
## Usage example
```C
void handle_led_state(Rgb* rgb, void* _ctx) {
printf("led: #%02X%02X%02X\n", rgb->red, rgb->green, rgb->blue);
}
void led_example(void* p) {
LedApi* led_api = open_display("/dev/led");
if(led_api == NULL) return; // led not available, critical error
// subscribe to led state updates
subscribe_led_changes(led_api->updates, handle_led_state, NULL);
Rgb current_state;
if(read_led(led_api->state, &current_state, OsWaitForever)) {
printf(
"initial led: #%02X%02X%02X\n",
current_state->red,
current_state->green,
current_state->blue
);
}
// add layer to control led
ValueManager* led_manager = add_led_layer(&current_state, UI_LAYER_APP);
// write only blue by getting pointer
Rgb* rgb = take_led(led_manager, OsWaitForever);
if(rgb != NULL) {
rgb->blue = 0;
}
commit_led(led_manager, rgb);
// write RGB value
write_led(led_manager, &(Rgb{.red = 0xFA, green = 0xCE, .blue = 0x8D}), OsWaitForever);
}
```