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low power delay ms

Hi i want to make a low power delay ms (blocking) function for nrf52805 without softdevice and without NRFx, just writing to the registers.

void RTC1_IRQHandler(void)
{
	NRF_RTC1->TASKS_STOP=1;
	NRF_RTC1->EVENTS_COMPARE[0]=0;
}

void helperLowPowerDelayMs(uint16_t ms)
{
	NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
	NRF_CLOCK->TASKS_LFCLKSTART=1;
	while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0){};


	NRF_RTC1->TASKS_STOP=1;
	NRF_RTC1->TASKS_CLEAR=1;
	NRF_RTC1->CC[0]=ms*33;
	NRF_RTC1->EVENTS_COMPARE[0]=0;
	NRF_RTC1->INTENSET=RTC_INTENSET_COMPARE0_Enabled<<RTC_INTENSET_COMPARE0_Pos;

	NVIC_ClearPendingIRQ(RTC1_IRQn);
	NVIC_SetPriority(RTC1_IRQn,1);
	NVIC_EnableIRQ(RTC1_IRQn);
	NRF_RTC1->TASKS_START=1;
	__WFI();
	NVIC_DisableIRQ(RTC1_IRQn);
}

The RTC1 events_tick never gets set, the rtc1 event cc 0 never gets set. the isr does not execute
.

what is the problem?

Parents

0 user15146 over 3 years ago

Hi,

Try adding

// Enable EVENTS_COMPARE[0] generation
NRF_RTC1->EVTENSET = RTC_EVTENSET_COMPARE0_Enabled << RTC_EVTENSET_COMPARE0_Pos;

Might also want to add a IRQ handler.

// IRQ handler
void RTC1_IRQHandler(void)
{
  volatile uint32_t dummy;
  if (NRF_RTC0->EVENTS_COMPARE[0] == 1)
  {
    NRF_RTC0->EVENTS_COMPARE[0] = 0;

    
    // Read back event register so ensure we have cleared it before exiting IRQ handler.
    dummy = NRF_RTC0->EVENTS_COMPARE[0];
    dummy;
  }
}

PS: I recommended using the nrfx driver.

Reply

0 user15146 over 3 years ago

Hi,

Try adding

// Enable EVENTS_COMPARE[0] generation
NRF_RTC1->EVTENSET = RTC_EVTENSET_COMPARE0_Enabled << RTC_EVTENSET_COMPARE0_Pos;

Might also want to add a IRQ handler.

// IRQ handler
void RTC1_IRQHandler(void)
{
  volatile uint32_t dummy;
  if (NRF_RTC0->EVENTS_COMPARE[0] == 1)
  {
    NRF_RTC0->EVENTS_COMPARE[0] = 0;

    
    // Read back event register so ensure we have cleared it before exiting IRQ handler.
    dummy = NRF_RTC0->EVENTS_COMPARE[0];
    dummy;
  }
}

PS: I recommended using the nrfx driver.

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