Lv_timer not work

Hi, I am new to use lvgl. when I create a timer to print something but the timer not run. In my device I create a task to run lvgl task handler and a task to run other code

void my_timer_cb(struct _lv_timer_t * timer)
LV_LOG_USER(“lv_timer_cb is call”);

void events_init_home(lv_ui_t *ui) {
// lv_obj_add_event_cb(ui->home, event_cb_home, LV_EVENT_CLICKED, NULL);
lv_timer_t *timer = lv_timer_create(my_timer_cb, 100, NULL);

void setup_scr_home(lv_ui_t *ui)
ui->home = lv_obj_create(NULL);

ui->btn = lv_btn_create(ui->home);
lv_obj_set_size(ui->btn, 100, 50);

ui->label = lv_label_create(ui->btn);
lv_label_set_text(ui->label , "home");



when the screen display. the timer not run

Do you call lv_tick_inc() somewhere?

Do the buttons work? If you press them do you see that they get darker?

yes ,other things like button in lvgl is ok,but the timer callback function can’t ouput the debug info, so it seems the timer not run.

Does logging work without timers, just called after lv_init()?

yes, we find out it is a bug in systerm. printf() can’t not be used in two task. thankyou for your answer