Light-Emitting Diode (LED)
Overview
The LED API provides access to Light Emitting Diodes, both in individual and strip form.
Configuration Options
Related configuration options:
API Reference
LED
- group led_interface
LED Interface.
- Since
1.12
- Version
1.0.0
Typedefs
-
typedef int (*led_api_blink)(const struct device *dev, uint32_t led, uint32_t delay_on, uint32_t delay_off)
Callback API for blinking an LED.
See also
led_blink() for argument descriptions.
-
typedef int (*led_api_get_info)(const struct device *dev, uint32_t led, const struct led_info **info)
Optional API callback to get LED information.
See also
led_get_info() for argument descriptions.
-
typedef int (*led_api_set_brightness)(const struct device *dev, uint32_t led, uint8_t value)
Callback API for setting brightness of an LED.
See also
led_set_brightness() for argument descriptions.
-
typedef int (*led_api_set_color)(const struct device *dev, uint32_t led, uint8_t num_colors, const uint8_t *color)
Optional API callback to set the colors of a LED.
See also
led_set_color() for argument descriptions.
-
typedef int (*led_api_on)(const struct device *dev, uint32_t led)
Callback API for turning on an LED.
See also
led_on() for argument descriptions.
-
typedef int (*led_api_off)(const struct device *dev, uint32_t led)
Callback API for turning off an LED.
See also
led_off() for argument descriptions.
-
typedef int (*led_api_write_channels)(const struct device *dev, uint32_t start_channel, uint32_t num_channels, const uint8_t *buf)
Callback API for writing a strip of LED channels.
See also
led_api_write_channels() for arguments descriptions.
Functions
-
int led_blink(const struct device *dev, uint32_t led, uint32_t delay_on, uint32_t delay_off)
Blink an LED.
This optional routine starts blinking a LED forever with the given time period.
- Parameters:
dev – LED device
led – LED number
delay_on – Time period (in milliseconds) an LED should be ON
delay_off – Time period (in milliseconds) an LED should be OFF
- Returns:
0 on success, negative on error
-
int led_get_info(const struct device *dev, uint32_t led, const struct led_info **info)
Get LED information.
This optional routine provides information about a LED.
- Parameters:
dev – LED device
led – LED number
info – Pointer to a pointer filled with LED information
- Returns:
0 on success, negative on error
-
int led_set_brightness(const struct device *dev, uint32_t led, uint8_t value)
Set LED brightness.
This optional routine sets the brightness of a LED to the given value. Calling this function after led_blink() won’t affect blinking.
LEDs which can only be turned on or off may provide this function. These should simply turn the LED on if
valueis nonzero, and off ifvalueis zero.- Parameters:
dev – LED device
led – LED number
value – Brightness value to set in percent
- Returns:
0 on success, negative on error
-
int led_write_channels(const struct device *dev, uint32_t start_channel, uint32_t num_channels, const uint8_t *buf)
Write/update a strip of LED channels.
This optional routine writes a strip of LED channels to the given array of levels. Therefore it can be used to configure several LEDs at the same time.
Calling this function after led_blink() won’t affect blinking.
- Parameters:
dev – LED device
start_channel – Absolute number (i.e. not relative to a LED) of the first channel to update.
num_channels – The number of channels to write/update.
buf – array of values to configure the channels with. num_channels entries must be provided.
- Returns:
0 on success, negative on error
-
int led_set_channel(const struct device *dev, uint32_t channel, uint8_t value)
Set a single LED channel.
This optional routine sets a single LED channel to the given value.
Calling this function after led_blink() won’t affect blinking.
- Parameters:
dev – LED device
channel – Absolute channel number (i.e. not relative to a LED)
value – Value to configure the channel with
- Returns:
0 on success, negative on error
-
int led_set_color(const struct device *dev, uint32_t led, uint8_t num_colors, const uint8_t *color)
Set LED color.
This routine configures all the color channels of a LED with the given color array.
Calling this function after led_blink() won’t affect blinking.
- Parameters:
dev – LED device
led – LED number
num_colors – Number of colors in the array.
color – Array of colors. It must be ordered following the color mapping of the LED controller. See the the color_mapping member in struct led_info.
- Returns:
0 on success, negative on error
-
struct led_info
- #include <led.h>
LED information structure.
This structure gathers useful information about LED controller.
-
struct led_driver_api
- #include <led.h>
LED driver API.
LED Strip
- group led_strip_interface
LED Strip Interface.
Typedefs
-
typedef int (*led_api_update_rgb)(const struct device *dev, struct led_rgb *pixels, size_t num_pixels)
Callback API for updating an RGB LED strip.
See also
led_strip_update_rgb() for argument descriptions.
-
typedef int (*led_api_update_channels)(const struct device *dev, uint8_t *channels, size_t num_channels)
Callback API for updating channels without an RGB interpretation.
See also
led_strip_update_channels() for argument descriptions.
-
typedef size_t (*led_api_length)(const struct device *dev)
Callback API for getting length of an LED strip.
See also
led_strip_length() for argument descriptions.
Functions
-
static inline int led_strip_update_rgb(const struct device *dev, struct led_rgb *pixels, size_t num_pixels)
Mandatory function to update an LED strip with the given RGB array.
Warning
This routine may overwrite pixels.
- Parameters:
dev – LED strip device.
pixels – Array of pixel data.
num_pixels – Length of pixels array.
- Return values:
0 – on success.
-errno – negative errno code on failure.
-
static inline int led_strip_update_channels(const struct device *dev, uint8_t *channels, size_t num_channels)
Optional function to update an LED strip with the given channel array (each channel byte corresponding to an individually addressable color channel or LED.
Channels are updated linearly in strip order.
Warning
This routine may overwrite channels.
- Parameters:
dev – LED strip device.
channels – Array of per-channel data.
num_channels – Length of channels array.
- Return values:
0 – on success.
-ENOSYS – if not implemented.
-errno – negative errno code on other failure.
-
struct led_rgb
- #include <led_strip.h>
Color value for a single RGB LED.
Individual strip drivers may ignore lower-order bits if their resolution in any channel is less than a full byte.
-
struct led_strip_driver_api
- #include <led_strip.h>
LED strip driver API.
This is the mandatory API any LED strip driver needs to expose.
-
typedef int (*led_api_update_rgb)(const struct device *dev, struct led_rgb *pixels, size_t num_pixels)