nrf52833 failed to wake up from SOFT_OFF

[binhla]

Dear all,

I am developing a device that base on nrf52833, nrf connect sdk ver 2.0.0

The device run bluetooth mesh. And becase it was powered  by battery, so it must go into sleep mode, and wake up by GPIOs in specific scenarios.

This is the function that put the device into sleep mode

void app_system_sleep(struct k_work *work_tem) {
	nrf_gpio_cfg_sense_input(wake_pin_1, NRF_GPIO_PIN_NOPULL, NRF_GPIO_PIN_SENSE_LOW);
	nrf_gpio_cfg_sense_input(wake_pin_2, NRF_GPIO_PIN_NOPULL, NRF_GPIO_PIN_SENSE_LOW);
	
	LREP(__func__,"Entering system off");
	bt_mesh_suspend();
	
	const struct pm_state_info si = {PM_STATE_SOFT_OFF, 0, 0};
	pm_state_force(0, &si);

	k_sleep(K_MSEC(100));
	
	LREP(__func__, "Exit sleep mode");
	NVIC_SystemReset();
}

After the deviced run for about 1-2 days, It failed to wake up via wake_pin_1 and wake_pin_2. And I must re-power it.

One thing I am not sure, when the device went into this error, Its current consumsion is about 500uA.

Please help me.

Best regards.

[Simonr]

Hi

Okay, you're using the Bluetooth Mesh. Mesh is in general a very power hungry as provisioned nodes need to continuously keep their radio in listening mode, which will indeed draw additional current. In order to enable low power devices (LPN) to take part in a Mesh network, you need to implement the Friendship feature. This lets low power devices establish a relationship with regular Mesh devices, which will then cache and forward messages to the low power device at regular intervals. 

In the nRF Connect SDK we don't have sample projects using LPNs and Friend nodes, but you can enable a friend node by setting this config CONFIG_BT_MESH_FRIEND. You can also add the LPN feature with the configs you can find by searching for CONFIG_BT_MESH_LPN in the KConfig search.

Best regards,

Simon

[binhla]

Dears,

Simonr said:

In order to enable low power devices (LPN) to take part in a Mesh network, you need to implement the Friendship feature. This lets low power devices establish a relationship with regular Mesh devices, which will then cache and forward messages to the low power device at regular intervals. 

Yes, this is a different approach for the bluetooth mesh.

What is the lowest current consumption of the nrf52833 from this LPN mode?

Best regards.