LED - rockcastle/lvgl GitHub Wiki

Written for v5.1

Overview

The LEDs are rectangle-like (or circle) object. You can set their brightness with lv_led_set_bright(led, bright). The brightness should be between 0 (darkest) and 255 (lightest).

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.

Style usage

The LED uses one style which can be set by lv_led_set_style(led, &style). To determine the appearance the style.body properties are used. The colors are darkened and shadow width is reduced at a lower brightness and gains its original value at brightness 255 to show a lighting effect. The default style is: lv_style_pretty_color.

Notes

  • Typically the default style is not suitable therefore you have to create you own style. See the Examples.

Example

LED image

/*Create a style for the LED*/
static lv_style_t style_led;
lv_style_copy(&style_led, &lv_style_pretty_color);
style_led.body.radius = LV_RADIUS_CIRCLE;
style_led.body.main_color = LV_COLOR_MAKE(0xb5, 0x0f, 0x04);
style_led.body.grad_color = LV_COLOR_MAKE(0x50, 0x07, 0x02);
style_led.body.border.color = LV_COLOR_MAKE(0xfa, 0x0f, 0x00);
style_led.body.border.width = 3;
style_led.body.border.opa = LV_OPA_30;
style_led.body.shadow.color = LV_COLOR_MAKE(0xb5, 0x0f, 0x04);
style_led.body.shadow.width = 10;


/*Create a LED and switch it ON*/
lv_obj_t * led1  = lv_led_create(lv_scr_act(), NULL);
lv_obj_set_style(led1, &style_led);
lv_obj_align(led1, NULL, LV_ALIGN_IN_TOP_MID, 40, 40);
lv_led_on(led1);

/*Copy the previous LED and set a brightness*/
lv_obj_t * led2  = lv_led_create(lv_scr_act(), led1);
lv_obj_align(led2, led1, LV_ALIGN_OUT_BOTTOM_MID, 0, 40);
lv_led_set_bright(led2, 190);

/*Copy the previous LED and switch it OFF*/
lv_obj_t * led3  = lv_led_create(lv_scr_act(), led1);
lv_obj_align(led3, led2, LV_ALIGN_OUT_BOTTOM_MID, 0, 40);
lv_led_off(led3);

/*Create 3 labels next to the LEDs*/
lv_obj_t * label = lv_label_create(lv_scr_act(), NULL);
lv_label_set_text(label, "LED On");
lv_obj_align(label, led1, LV_ALIGN_OUT_LEFT_MID, -40, 0);

label = lv_label_create(lv_scr_act(), NULL);
lv_label_set_text(label, "LED half");
lv_obj_align(label, led2, LV_ALIGN_OUT_LEFT_MID, -40, 0);

label = lv_label_create(lv_scr_act(), NULL);
lv_label_set_text(label, "LED Off");
lv_obj_align(label, led3, LV_ALIGN_OUT_LEFT_MID, -40, 0);