How to disable NRF52832 BLE power shutdown?

RE: How to disable NRF52832 BLE power shutdown?

Einar Thorsrud — Thu, 13 Dec 2018 11:59:07 GMT

Hi,

Thank you letting us know what it was 🙂 I had no idea that this functionality existed in the SDK...

RE: How to disable NRF52832 BLE power shutdown?

dimtai — Thu, 13 Dec 2018 11:22:19 GMT

Hi Eina, many thanks for the hints.

Problem solved. There is a shutdown counter in the nrf_pwr_mgmt.c, which is enabled by NRF_PWR_MGMT_CONFIG_STANDBY_TIMEOUT_ENABLED

Best regards, Dimtai

RE: How to disable NRF52832 BLE power shutdown?

Einar Thorsrud — Wed, 12 Dec 2018 11:37:33 GMT

Hi,

There should not be any such counter in the SDK, so I am curious about seeing your code. Can you upload your complete project to this thread?

Br,

Einar

RE: How to disable NRF52832 BLE power shutdown?

dimtai — Wed, 12 Dec 2018 11:29:19 GMT

Is that possible that buttons_leds_init(&erase_bonds) actually starts a timer? And does it have a counter ticking?

RE: How to disable NRF52832 BLE power shutdown?

dimtai — Wed, 12 Dec 2018 10:54:58 GMT

Hi Einar, thanks for the answer.

I don't know what happens with "shutdown", as I couldn't trace into the code. The CPU's current consumption goes from about 0.3mA down to about 0.3uA when it's down and ble is also gone, but it can be awaken by a button press. I assume it's a system OFF mode.

There is a constant periodic call of idle_state_handle() at precisely 1 sec interval in main() for loop. If PWR_MGMT_FPU_SLEEP_PREPARE() is commented out, the ticks go a lot faster, with irregular intervals much less than 0.1 sec. I don't know where this is from. SOFTDEVICE_PRESENT is present in this case, but it appears that the 1 sec interval is not from sd_app_evt_wait().

There is no timer started in the case, although app_timer_init() is surely called in init_ble(), otherwise BLE will not work. The actual init_ble() is as follows.

void init_ble(void)
{
	bool erase_bonds = 1;
	// Initialize.
	app_timer_init();
	log_init();
	buttons_leds_init(&erase_bonds);
	power_management_init();

	//BLE related initialization
	ble_stack_init();
	gap_params_init();
	gatt_init();
	services_init();
	advertising_init();
	conn_params_init();
	advertising_start(erase_bonds, BLE_ADV_MODE_FAST);
}

The shutdown happens accurately when 3600 counts are achieved calling idle_state_handle(), and so I guess there should be a clock ticking somewhere. My question is: how to find this counter and how to clear it? And by doing so, can I disable NRF52832 power shutdown momentarily?

Thanks again. Best regards, dimtai.

RE: How to disable NRF52832 BLE power shutdown?

Einar Thorsrud — Tue, 11 Dec 2018 13:11:09 GMT

Hi,

By shutdown, what exactly do you mean? System OFF mode?

Are you confident that PWR_MGMT_FPU_SLEEP_PREPARE() is related? It doesn't makes sense to me when I am looking at the code. Regarding PWR_MGMT_FPU_SLEEP_PREPARE(), this will be pwr_mgmt_fpu_sleep_prepare() if you have NRF_PWR_MGMT_CONFIG_FPU_SUPPORT_ENABLED set to 1 in your projects sdk_config.h. If not, it will just be replaced with nothing by the preprocessor (no function call at all).

Are you sure there is no timer or other event that causes your device to go into some kind of idle state?