How to remove the vertical line at the beginning?

What do you want to achieve?

Where does the vertical line appear, how to remove it. Refreshing occurs every 100 ms, in test mode I refresh the chart with a value of 20.

What have you tried so far?

I have tried erasing all the dots without much success.

lv_chart_set_all_value(obj, ser, LV_CHART_POINT_NONE);

Code to reproduce

/// initialization
            lv_chart_set_type(obj, LV_CHART_TYPE_LINE);

            auto points = Param_Manager_c::getValue("data_points_online");
            const uint32_t max_points = points * 2;
            lv_chart_set_point_count(obj, max_points);

            lv_obj_set_style_pad_all(obj, 0, 0);
            lv_obj_set_style_radius(obj, 0, 0);
            lv_obj_set_style_size(obj, 0, 0, LV_PART_INDICATOR);

            lv_chart_set_div_line_count(obj, 7, 7);

            auto val_min_Y = Param_Manager_c::getValue("data_scale_chart_min_on");
            auto val_max_Y = Param_Manager_c::getValue("data_scale_chart_max_on");
            lv_chart_set_range(obj, LV_CHART_AXIS_PRIMARY_Y, val_min_Y, val_max_Y);

            auto ser = lv_chart_add_series(obj, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);

            lv_obj_set_style_line_width(obj, 1, LV_PART_ITEMS);   /*Remove the lines*/

            auto scale_left = Widget_Manager_c::getWidget("scale_chart_ver_online");
            lv_scale_set_range(scale_left, val_min_Y, val_max_Y);
            lv_obj_set_style_pad_ver(scale_left, lv_chart_get_first_point_center_offset(obj), 0);

            auto scale_gor = Widget_Manager_c::getWidget("scale_chart_hor_online");
            auto val = Param_Manager_c::getValue("chart_period_signal");
            lv_scale_set_range(scale_gor, timeArray[val], 0);

            auto time_lb = Widget_Manager_c::getWidget("chart_text_area_time");
            lv_textarea_set_text(time_lb, TimeCodes[val].c_str());

            lv_chart_set_all_value(obj, ser, LV_CHART_POINT_NONE);

///Update
           for (size_t i = 0; i < validCount && cnt < max_points; ++i) 
           {
                    lv_chart_set_value_by_id(chart, ser, cnt--, 20.0f);
                    lv_chart_set_value_by_id(chart, ser, cnt--, 20.0f);

                    if (cnt == 0) {
                        trace_printf("Chart_trand_view::update: Reached max points (%d)\n", max_points);
                        break;
                    }
             }

Screenshot and/or video

Environment

  • MCU/MPU/Board: stm32h743
  • LVGL version: #define LVGL_VERSION_MAJOR 9
    #define LVGL_VERSION_MINOR 3
    #define LVGL_VERSION_PATCH 0
    #define LVGL_VERSION_INFO “dev”

Can anyone answer why this vertical line appears at the beginning of the graph, how can it be removed?