lvgl/examples/widgets/chart/lv_example_chart_8.c

#include "../../lv_examples.h"
#if LV_USE_CHART && LV_DRAW_SW_COMPLEX && LV_BUILD_EXAMPLES


static void add_data(lv_timer_t * t)
{
    lv_obj_t * chart = t->user_data;
    lv_chart_series_t * ser = lv_chart_get_series_next(chart, NULL);

    lv_chart_set_next_value(chart, ser, lv_rand(10, 90));

    uint16_t p = lv_chart_get_point_count(chart);
    uint16_t s = lv_chart_get_x_start_point(chart, ser);
    lv_coord_t * a = lv_chart_get_y_array(chart, ser);

    a[(s + 1) % p] = LV_CHART_POINT_NONE;
    a[(s + 2) % p] = LV_CHART_POINT_NONE;
    a[(s + 2) % p] = LV_CHART_POINT_NONE;

    lv_chart_refresh(chart);
}

/**
 * Circular line chart with gap
 */
void lv_example_chart_8(void)
{
    /*Create a stacked_area_chart.obj*/
    lv_obj_t * chart = lv_chart_create(lv_screen_active());
    lv_chart_set_update_mode(chart, LV_CHART_UPDATE_MODE_CIRCULAR);
    lv_obj_set_style_size(chart, 0, 0, LV_PART_INDICATOR);
    lv_obj_set_size(chart, 280, 150);
    lv_obj_center(chart);

    lv_chart_set_point_count(chart, 80);
    lv_chart_series_t * ser = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
    /*Prefill with data*/
    uint32_t i;
    for(i = 0; i < 80; i++) {
        lv_chart_set_next_value(chart, ser, lv_rand(10, 90));
    }

    lv_timer_create(add_data, 300, chart);

}

#endif