fix(timer) delay execution only until the next timer fires up (#61)

* fix(timer) delay execution only until the next timer fires up

lv_timer_handle returns the time in ms until the next timer will fire.
We need to delay only that much time for optimal execution.

Signed-off-by: Cristian Stoica <[email protected]>

* Update main.c

Co-authored-by: Gabor Kiss-Vamosi <[email protected]>

---------

Signed-off-by: Cristian Stoica <[email protected]>
Co-authored-by: Gabor Kiss-Vamosi <[email protected]>

main.c

@@ -78,8 +78,8 @@ int main(void)
 
     /*Handle LVGL tasks*/
     while(1) {
-        lv_timer_handler();
-        usleep(5000);
+        uint32_t idle_time = lv_timer_handler(); /*Returns the time to the next timer execution*/
+        usleep(idle_time * 1000);
     }
 
     return 0;