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.. include:: /header.rst
:github_url: |github_link_base|/porting/tick.md
Tick interface
LVGL needs a system tick to know elapsed time for animations and other tasks.
You need to call the lv_tick_inc(tick_period) function periodically and provide the call period in milliseconds. For example, lv_tick_inc(1) when calling every millisecond.
lv_tick_inc should be called in a higher priority routine than lv_task_handler() (e.g. in an interrupt) to precisely know the elapsed milliseconds even if the execution of lv_task_handler takes more time.
With FreeRTOS lv_tick_inc can be called in vApplicationTickHook.
On Linux based operating systems (e.g. on Raspberry Pi) lv_tick_inc can be called in a thread like below:
void * tick_thread (void *args)
{
while(1) {
usleep(5*1000); /*Sleep for 5 millisecond*/
lv_tick_inc(5); /*Tell LVGL that 5 milliseconds were elapsed*/
}
}
API
.. doxygenfile:: lv_hal_tick.h
:project: lvgl