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Increment epoch time from vTickISR

Posted by savindra on March 1, 2017

Hi ,

I am following below method to sync my external RTC with internal timer. Incrementing epoch millliseconds from vTickISR.

But i want to sync my epoch milliseconds with external RTC just after my system startsup. But vTickISR is called when FreeRTOS scheduler is started so i have to wait till scheduler is started. Is there any function in FreeRTOS that can tell me that scheduler is started so that once scheduler is started i can sync my epcohms with RTC and it keep on incrementing just after syncing.

LiBIncEpochTime() { g_ulEpochMs++; }

pragma interrupt ( vTickISR( vect = VECT( configTICKVECTOR ), enable ) )

void vTickISR( void ) { / Increment the tick, and perform any processing the new tick value necessitates. / ///increment epoch seconds LIBIncEpochTime();

	if( xTaskIncrementTick() != pdFALSE )


Regards, Savindra

Increment epoch time from vTickISR

Posted by rtel on March 1, 2017

Look at line 552 (at the time of writing) in the following file.


If you set configUSEDAEMONTASKSTARTUPHOOK to 1 you must provide an implementation of:

void vApplicationDaemonTaskStartupHook( void );

Assuming the timer task is the highest priority task in the system - which is normally the case - then vApplicationDaemonTaskStartupHook() will get called once when the first task starts executing.

Does that meet your needs?

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