nRF5340 BLE current consumption

[BENBF]

Hello,

I'm currently using nRF5340 as BLE transmitter, however, it appears that input current it quite high even when the device is not advertising.

I made a small code that initialise BLE and that enable and disable advertising periodically with bt_le_adv_start() and bt_le_adv_stop() functions. As soon as the BLE is configured, the current goes up to and remains around 8 mA (average).

Is there any way to reduce current consumption when nRF5340 is not advertising ?

Thank you,
Best regards

[runsiv]

Hi

I would recommend having a look at a few things:

Power optimization

This blog we wrote some years ago. You might not be able to use the exact same code as Zephyr and NCS has developed over time. However the techincis mentioned in the blog is still valid.

You can compare your application against our online power profiler tool

Regards

Runar

[BENBF]

Hello,

Thank you for your answer and the documentation.
I followed the various recommendations and I managed to reduce consumption and most importantly, I managed to get a "normal' consumption after performing the bt_le_adv_stop() function.

I still get around a 100 µA when the device is in  PM_STATE_SOFT_OFF instead of the few µA mentioned in your blog, but I'm guessing it is because I'm still using the QSPI interface connected to a nRF7002.

Also, concerning power down the peripherals, I couldn't find the function pm_device_state_set() using NCS v2.4.2, has it been removed since the article on the blog ?

Using the nRF7002, I'm observing quite an important overall consumption (around 20 mA) before the interface is initialised and when the interface is down (greater than when the interface is up)  which intrigue me. Do you have an idea of what could cause this consumption ?

My program is starting by initialising BLE and WiFi before starting WiFi interface then shutting it down. It then starts BLE advertising.

This is what I observe for the overall consumption:

And this is what I oberve when monitoring only nRF5340 consumption:


I can create a dedicated ticket if you prefer.

Thank you,
Best regards

[runsiv]

Hi 

I think the 7002 part would be best to take in another post just to keep it to one topic for each thread. I would however highly recommend that if you are using WIFI to upgrade to NCS 2.5.2 as it contains multiple wifi patches that affects power consumption. A new release of NCS 2.6 is also on its way but I can't disclose release dates here on devzone as it is a roadmap question and has to go through sales. We have a migration guide that will make it migration to NCS 2.5 easier. You can also see there is a migration guide draft for 2.6. So it might be worth considering using the main branch and change to 2.6 when it is released. 

I would suspect the communication with the 7002 affects the current you can see the typical GPIO current draw for QSPI is 10mA here. however the numbers does not add up, so it could also be a floating pin. If you want to just measure the 5340 you could also have a look at this sample  

It is also worth mentioning the following:

"Note: The current measurements are unreliable if a serial terminal is connected to the virtual serial port."

and

"It is not recommended to use a USB connector to power the Development Kit (DK) during current measurements due to potential noise from the USB power supply. "

Regards

Runar

[BENBF]

Hello,

Thank you for your answer.
I'll try to migrate SDK to v2.5.2 before a dedicated ticket for nRF7002 consumption.

Concerning the QSPI consumption, I think it can be observed on the second figure (the two peaks at the beginning corresponding, I think, to the start and the stop of the interface). The current is less than 10 mA but maybe my sampling was no set properly to measure those events.

The second figure I sent was the consumption of the nRF5340 only, I'm currently working on a custom board on which this measurements is possible.

Thank you,
Best regards