lvgl_chart.tc

lvgl_chart.tc — LVGL Phase 3 demo (requires firmware with USE_TINYC_LVGL)

Source on GitHub

// lvgl_chart.tc — LVGL Phase 3 demo (requires firmware with USE_TINYC_LVGL)
//
// A live line chart that scrolls a triangle wave. Shows the Phase 3 chart API:
// chart create + type + point count + axis range + a coloured series + set-next.
// (Phase 3 also adds lvglImage()/lvglImageSrc() for FS images — not shown here as
// it needs an image asset uploaded to the device FS.)

#define ALIGN_TOP_MID   2
#define ALIGN_CENTER    9
#define CHART_LINE      1     // lv_chart_type_t: 1=LINE, 2=BAR
#define AXIS_PRIMARY_Y  0

int chart;
int ser;
int v = 0;
int dir = 1;

int main() {
    lvglInit();
    lvglSetBgColor(0, 0x101820);

    int title = lvglLabel(0);
    lvglSetText(title, "Phase 3: live chart");
    lvglSetTextColor(title, 0xFFFFFF);
    lvglAlign(title, ALIGN_TOP_MID, 0, 8);

    chart = lvglChart(0);
    lvglSetSize(chart, 280, 180);
    lvglAlign(chart, ALIGN_CENTER, 0, 20);
    lvglChartType(chart, CHART_LINE);
    lvglChartCount(chart, 50);
    lvglChartRange(chart, AXIS_PRIMARY_Y, 0, 100);
    ser = lvglChartSeries(chart, 0x40c0ff);

    // scroll a 0..100 triangle wave across the chart
    while (1) {
        v = v + dir * 5;
        if (v >= 100) { v = 100; dir = -1; }
        if (v <= 0)   { v = 0;   dir = 1; }
        lvglChartNext(chart, ser, v);
        delay(150);
    }
    return 0;
}