samd21: enable SysTick only if running w/o OS
@@ -75,7 +75,9 @@ void board_init(void)
// Update SystemCoreClock since it is hard coded with asf4 and not correct
// Init 1ms tick timer (samd SystemCoreClock may not correct)
SystemCoreClock = CONF_CPU_FREQUENCY;
+#if CFG_TUSB_OS == OPT_OS_NONE
SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#endif
// Led init
#ifdef LED_PIN
