LED (lv_led)

Overview

LEDs are rectangle-like (or circle) Widgets whose brightness can be adjusted. With lower brightness the color of the LED becomes darker.

Parts and Styles

• LV_LED_PART_MAIN uses the typical background style properties.

Usage

Color

You set the color of the LED with lv_led_set_color(led, lv_color_hex(0xff0080)). This will be used as its background color, border color, and shadow color.

Brightness

You can set their brightness with lv_led_set_brightness(led, brightness). The brightness value should be in the range 0 (darkest) to 255 (lightest).

Toggle

Use lv_led_on(led) and lv_led_off(led) to set the brightness to a predefined ON or OFF value. The lv_led_toggle(led) toggles between the ON and OFF state.

You can set custom LED ON and OFF brightness values by defining macros LV_LED_BRIGHT_MAX and LV_LED_BRIGHT_MIN in your project. Their default values are 80 and 255. These too must be in the range [0..255].

Events

No special events are sent by LED Widgets.

Further Reading

Learn more about Base-Widget Events emitted by all Widgets.

Learn more about Events.

Keys

No Keys are processed by LED Widgets.

Further Reading

Learn more about Keys.

Example

LED with custom style

C code  

 View on GitHub

#include "../../lv_examples.h"
#if LV_USE_LED && LV_BUILD_EXAMPLES

/**
 * Create LED's with different brightness and color
 */
void lv_example_led_1(void)
{
    /*Create a LED and switch it OFF*/
    lv_obj_t * led1  = lv_led_create(lv_screen_active());
    lv_obj_align(led1, LV_ALIGN_CENTER, -80, 0);
    lv_led_off(led1);

    /*Copy the previous LED and set a brightness*/
    lv_obj_t * led2  = lv_led_create(lv_screen_active());
    lv_obj_align(led2, LV_ALIGN_CENTER, 0, 0);
    lv_led_set_brightness(led2, 150);
    lv_led_set_color(led2, lv_palette_main(LV_PALETTE_RED));

    /*Copy the previous LED and switch it ON*/
    lv_obj_t * led3  = lv_led_create(lv_screen_active());
    lv_obj_align(led3, LV_ALIGN_CENTER, 80, 0);
    lv_led_on(led3);
}

#endif

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API

lv_led.h

lv_led_private.h