led.h File Reference

API Description

LED is the Light Emitting Diode interface to libmraa. It is used to access the on board LED's via sysfs.

Go to the source code of this file.

Functions
mraa_led_context	mraa_led_init (int led)
mraa_led_context	mraa_led_init_raw (const char *led_dev)
mraa_result_t	mraa_led_set_brightness (mraa_led_context dev, int value)
int	mraa_led_read_brightness (mraa_led_context dev)
int	mraa_led_read_max_brightness (mraa_led_context dev)
mraa_result_t	mraa_led_set_trigger (mraa_led_context dev, const char *trigger)
mraa_result_t	mraa_led_clear_trigger (mraa_led_context dev)
mraa_result_t	mraa_led_close (mraa_led_context dev)

Typedefs
typedef struct _led *	mraa_led_context

Function Documentation

mraa_result_t mraa_led_clear_trigger

(

mraa_led_context

dev

)

Clear active LED trigger

Parameters

dev	LED context

Returns

Result of operation

mraa_result_t mraa_led_close

(

mraa_led_context

dev

)

Close LED file descriptors and free the context memory

Parameters

dev	LED context

Returns

Result of operation

mraa_led_context mraa_led_init

(

int

led

)

Initialise led_context, based on led index.

Parameters

led	ID of the LED

Returns

LED context or NULL

mraa_led_context mraa_led_init_raw

(

const char *

led_dev

)

Initialise led_context, based on led function name. The structure of LED entry in sysfs is "devicename:colour:function" This api expects only one unique LED identifier which would be "function" name most often. For instance, mraa_led_init_raw("user4");

Parameters

led_dev

Name of the LED device

Returns

LED context or NULL

int mraa_led_read_brightness

(

mraa_led_context

dev

)

Read LED brightness

Parameters

dev	LED context

Returns

Brightness value

int mraa_led_read_max_brightness

(

mraa_led_context

dev

)

Read LED maximum brightness

Parameters

dev	LED context

Returns

Maximum brightness value

mraa_result_t mraa_led_set_brightness	(	mraa_led_context	dev,
		int	value
	)

Set LED brightness

Parameters

dev	LED context
value	Integer value to write

Returns

Result of operation

mraa_result_t mraa_led_set_trigger	(	mraa_led_context	dev,
		const char *	trigger
	)

Set LED trigger

Parameters

dev	LED context
trigger	Type of trigger to set

Returns

Result of operation

Typedef Documentation

typedef struct _led* mraa_led_context

Opaque pointer definition to the internal struct _led

Include dependency graph for led.h: