Sleep does not work with BLE advertise

Question

Hi,

nRF52832, SDK 17.1.0 with Softdevice S132.

Softdevice sleep does not work when advertising. Application flow is to advertise one packet, then go to sleep for X seconds. Sleep part waits for a flag from "BLE_GAP_EVT_ADV_SET_TERMINATED" event.

If "sd_app_evt_wait" is replaced with "__WFI" when sleep works but BLE does not advertise anymore(even BLE_GAP_EVT_ADV_SET_TERMINATED is received).

Any idea how to put device to sleep?

This code works

	//BLE::advertise(&data, sizeof(data));

	while (1)
	{
		/*if (System::isWoken() == Return_t::OK)
		{
			BLE::advertise(&data, sizeof(data));
		}*/

		//if (BLE::isAdvertiseDone() == Return_t::OK)
		if (1)
		{
			System::startWakeupTimer();
			System::sleep();
		}

		// Feed the dog
		System::feedWatchdog();
	}

This code does not work(consumption around ~3.5mA)

	BLE::advertise(&data, sizeof(data));

	while (1)
	{
		if (System::isWoken() == Return_t::OK)
		{
			BLE::advertise(&data, sizeof(data));
		}

		if (BLE::isAdvertiseDone() == Return_t::OK)
		//if (1)
		{
			System::startWakeupTimer();
			System::sleep();
		}

		// Feed the dog
		System::feedWatchdog();
	}

sleep function:

	void sleep(void)
	{
		__set_FPSCR(__get_FPSCR()  & ~(0x0000009F));      
		(void) __get_FPSCR();
		sd_nvic_ClearPendingIRQ(FPU_IRQn);		

		sd_power_dcdc_mode_set(NRF_POWER_DCDC_DISABLE);

		_PRINT("Sleep\n");
		sd_app_evt_wait();

		sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE);
	}

Only RTC2 IRQ is enabled. FPU is disabled(soft FPU is used).

System init

	Return_t init(void)
	{
		// Test crystals only in debug build
		#ifdef DEBUG
		_PRINT("Wait for HFXO\n");
		NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
		NRF_CLOCK->TASKS_HFCLKSTART = 1;
		while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);
		NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;	
		_PRINT("HFXO started\n");

		_PRINT("Wait for LFXO\n");
		NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
		NRF_CLOCK->TASKS_LFCLKSTART = 1;
		while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
		NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;	
		_PRINT("LFXO started\n");		
		#endif // DEBUG

		// Configure power
		NRF_POWER->POFCON = 0;
		NRF_POWER->DCDCEN = 1;

		// Init watchdog
		NRF_WDT->CRV = (AppConfig::wdtTimeout * 32768) - 1;
		#ifdef DEBUG
		NRF_WDT->CONFIG = 1;
		#else
		NRF_WDT->CONFIG = 9;
		#endif // DEBUG
		NRF_WDT->TASKS_START = 1;

		// Enable RTC interrupt
		ret_code_t ret = sd_nvic_SetPriority(RTC2_IRQn, 2);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}

		ret = sd_nvic_EnableIRQ(RTC2_IRQn);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}

		// Enable compare0 interrupt
		NRF_RTC2->INTENSET = (1 << 16);

		// Set counter resolution of 125ms
		NRF_RTC2->PRESCALER = 4095;

		startWakeupTimer();
		return Return_t::OK;
	}
	
	void startWakeupTimer(void)
	{
		NRF_RTC2->TASKS_CLEAR = 1;
		NRF_RTC2->CC[0] = (AppConfig::measurePeriod * 1000) / 125;
		NRF_RTC2->TASKS_START = 1;
		_PRINT_INFO("Wakeup timer started\n");
	}

EDIT: BLE init functions

	Return_t init(void)
	{
		ret_code_t ret;

		ret = nrf_sdh_enable_request();
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}
	
		// Configure the BLE stack using the default settings.
		uint32_t ramStart = 0;
		ret = nrf_sdh_ble_default_cfg_set(AppConfig::bleTag, &ramStart);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}
	
		// Enable BLE stack.
		ret = nrf_sdh_ble_enable(&ramStart);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}
	
		// Register a handler for BLE events.
		NRF_SDH_BLE_OBSERVER(m_ble_observer, 3, onBLEEvent, NULL);

		// Init GAP profile
		if (gapInit() != Return_t::OK)
		{
			return Return_t::NOK;
		}	

		// Get MAC address
		ble_gap_addr_t addr;
		ret = sd_ble_gap_addr_get(&addr);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}		
		_PRINTF_INFO("MAC: %02X%02X%02X%02X%02X%02X\n", addr.addr[5], addr.addr[4], addr.addr[3], addr.addr[2], addr.addr[1], addr.addr[0]);

		// Request HFXO
		ret = sd_clock_hfclk_request();
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}		

		// Init advertise
		return advInit();
	}

	/**
	 * @brief Advertise data.
	 * 
	 * @return \c Return_t::NOK on fail.
	 * @return \c Return_t::OK on success.
	 */
	Return_t advertise(const void* data, const uint8_t len)
	{
		// Set custom data
		ble_advdata_manuf_data_t mnfData;
		
		mnfData.company_identifier = AppConfig::bleMnfID;
		mnfData.data.p_data = (uint8_t*)data;
		mnfData.data.size = len;
	
		// Set advertise data
		ble_advdata_t advData;
		memset(&advData, 0, sizeof(advData));
		advData.name_type = BLE_ADVDATA_FULL_NAME;
		advData.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
		advData.p_manuf_specific_data = &mnfData;
		advData.p_tx_power_level = &txPower;
	
		// Encode advertise data
		ret_code_t ret = ble_advdata_encode(&advData, gapAdvData.adv_data.p_data, &gapAdvData.adv_data.len);
		if (ret != NRF_SUCCESS)
		{	
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}

		// Advertise data
		advDone = 0;
		ret = sd_ble_gap_adv_start(advHandle, AppConfig::bleTag);
		if (ret != NRF_SUCCESS)
		{
			APP_ERROR_CHECK(ret);
			return Return_t::NOK;
		}		

		return Return_t::OK;
	}
	
/**
 * @brief Init BLE GAP profile.
 * 
 * @return \c Return_t::NOK on fail.
 * @return \c Return_t::OK on success.
 */
static Return_t gapInit(void)
{
	ble_gap_conn_sec_mode_t securtiyMode;
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&securtiyMode);

	ret_code_t ret = sd_ble_gap_device_name_set(&securtiyMode, (const uint8_t*)AppConfig::deviceName, __CONST_STR_LEN(AppConfig::deviceName));
	if (ret != NRF_SUCCESS)
	{
		APP_ERROR_CHECK(ret);
		return Return_t::NOK;
	}

	return Return_t::OK;
}

/**
 * @brief Init BLE advertise.
 * 
 * @return \c Return_t::NOK on fail.
 * @return \c Return_t::OK on success. 
 */
static Return_t advInit(void)
{
	// Set advertise config
	advConfig.primary_phy = BLE_GAP_PHY_AUTO;
	advConfig.duration = 0;
	advConfig.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_SCANNABLE_UNDIRECTED;
	advConfig.max_adv_evts	= AppConfig::advCount;
	advConfig.p_peer_addr = nullptr;
	advConfig.filter_policy = BLE_GAP_ADV_FP_ANY;
	advConfig.interval = 32; // Does not matter since max advertise event is set to 1 

	ret_code_t ret = sd_ble_gap_adv_set_configure(&advHandle, &gapAdvData, &advConfig);
	if (ret != NRF_SUCCESS)
	{	
		APP_ERROR_CHECK(ret);
		return Return_t::NOK;
	}

	// Set TX power
	ret = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, advHandle, txPower);
	if (ret != NRF_SUCCESS)
	{	
		APP_ERROR_CHECK(ret);
		return Return_t::NOK;
	}		

	return Return_t::OK;
}

Einar Thorsrud · Accepted Answer

Hi, 
 silvio3105 said: Should I wait for advertise to end or just go to sleep without waiting?

Go to sleep withotu waiting. 
 silvio3105 said: If I get you right - I should call SD sleep from main loop only if there is nothing else to do? 
 No, always call sd_app_evt_wait() from the main loop. This way, the CPU will enter sleep whenever there is nothing to do, and be woken up when there is work to do (the SoftDevice will wake up on RTC0 for anythign it shoudl do), your application wakes up on other interrupts, for instance RTC2 (also RTC1 if you use the app_timer), and any other interrupt sources (could for instance be GPIO pin interrupt). 
 silvio3105 said: Something like this:

No. It is essential that you enter sleep also when advertising. There is no point in spending power on busy waiting the CPU when advertising, whcih most of the time is waiting for the next advertising event. 
 silvio3105 said: Why are there double peaks? 
 I would need to see a much zoomed in view to be able to see what this current consumption pattern could represent (though I notice they are periodic). 
 silvio3105 said: Why Softdevice wakes up the device when it does not scan or advertise? Seems odd to me. 
 Do you use a 32.768 kHz crystall or the internal LFRC? If you use the internal LFRC, you probably (and must) enable regular calibration of the LFRC. The SoftDevice will wake up to perform check temperature and perform calibration, normally every 4 seconds (this is configured when initializing the SoftDevice). This happens a bit too often for that to be likely, but you could check the configuration. Other than that, then SoftDevice will normally only wake up when there are Bluetooth events (scanning, advertising or maintaing a connection).

Sleep does not work with BLE advertise

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