Arc

Arc with rotating percentage label

Report the arc value on a label that orbits with the knob.

A 150 by 150 arc sweeps 270 degrees starting at rotation 135 and begins at value 10. An LV_EVENT_VALUE_CHANGED callback writes the current value into a label as <v>% and calls lv_arc_rotate_obj_to_angle with a 25 px radius so the label follows the knob. The initial label is primed with lv_obj_send_event.

Arc loader animation

Centered 360 degree arc fills from 0 to 100 in a one-second loop.

A centered arc has its background angles set to a full 360 degrees starting at rotation 270, with the knob style removed and LV_OBJ_FLAG_CLICKABLE cleared so it cannot be dragged. An lv_anim_t drives lv_arc_set_value from 0 to 100 across 1000 ms with a 500 ms repeat delay and LV_ANIM_REPEAT_INFINITE.

Clickable pie chart with exploding slices

Five coloured arc slices pop outward when clicked and snap back.

A flex-row container holds a 150 by 150 slice canvas built from five overlapping arcs (12%, 18%, 26%, 24%, 20%) created with LV_ARC_MODE_NORMAL, each taking a share of the full circle via lv_arc_set_bg_start_angle and lv_arc_set_bg_end_angle. Each slice carries its own percentage label positioned along its midpoint and enables LV_OBJ_FLAG_ADV_HITTEST so clicks register on the wedge shape. An LV_EVENT_CLICKED callback animates the slice 20 px outward along the slice midpoint over 200 ms, reversing it on a second click and pulling any previously exploded slice back in.