from system on to system off

[UBAN]

I am using the nRF5_SDK_11.0.0.

I want to state of the system off sleep after entering system on sleep.

For example, from the state of system on sleep, it becomes system off sleep after 5 seconds.

However, it did not escape from the state of system on sleep with the __SEV();__WFE(); __WFE();.

Could you give me some advice? main.c

[Ole Bauck]

__WFE() will put the system to sleep (system on sleep) until an interrupt happens. Also see this.

You should start a timer which will interrupt your code after 5 seconds and the go to sleep with __SEV();__WFE(); __WFE();. When the interrupt happens you can go to system off sleep.

[UBAN]

Thank you for your advice. I wrote the code to become a state of system off sleep after entering system on sleep.Attach the main.c. However, the current value of system on sleep is large (0.3mA). Is main.c wrong ? Please tell me some reason.

[Ole Bauck]

The 300uA you are seeing is because the HFCLK is running while the chip is sleeping. You should use the LFCLK instead (uses about 1uA). This is done by using the RTC peripheral instead of the TIMER peripheral.

[UBAN]

I tried to use the RTC. The following is the code.

void rtc_config1(void)

{

  NRF_RTC1->TASKS_STOP = 1;	// Stop timer

  NRF_RTC1->PRESCALER = 4;	// 1us resolution

  NRF_RTC1->TASKS_CLEAR = 1; // Clear timer

  NRF_RTC1->CC[1] = TRIGGER_INTERVAL1 * 5000; 

  NRF_RTC1->INTENSET = RTC_INTENSET_COMPARE1_Enabled << RTC_INTENSET_COMPARE1_Pos; 

  //attachInterrupt(RTC1_IRQn, RTC1_Interrupt);    // also used in variant.cpp to configure the RTC1 

  NVIC_EnableIRQ(RTC1_IRQn);

NRF_RTC1->TASKS_START = 1;	// Start TIMER

}

void RTC1_IRQHandler(void)

{

  if (NRF_RTC1->EVENTS_COMPARE[1] != 0)

  {

NRF_POWER->SYSTEMOFF = 1;

NRF_RTC1->EVENTS_COMPARE[1] = 0;
		
  }

}

However, interruption is not performed. Could you give me some advice?

[Ole Bauck]

With the RTC you also need to enable the event:

NRF_RTC1->EVTENSET = RTC_EVTENSET_COMPARE1_Enabled << RTC_EVTENSET_COMPARE1_Pos;

See this section in the Product Specification.