Avoid usage of the network processor

[marvinwolf]

Hi,

i have switched from the 52840Dk to the 5340Dk because of the higher memory i need for my project.

The project is finished and at the moment i am measuring the power consumption.

I am having a bit of trouble with this as the measurements arent completely consistent

(Infrequently get 0.2 mA average less).

I want to eliminate the network core as a factor of power usage.

I am building fort the nrf5340dk_nrf5340_cpuapp but the network core seems to be flashed aswell.

Zephyr seems to find its way on it. The network core seems to be failing to boot, as the output stays like this:

Is there any way to completely disable the network core or "leave it empty"?

Thanks in advance!

[Einar Thorsrud]

Hi,

Generally, if you make an application for the application core, that is no problem. But if you build an application that use the radio, like a Bluetooth application, you will get a network core image as child image by default, as it is needed. 

What is you are application doing? Is it for instance using the radio? If not, what else can you say about your project and what you are building for the network core (if you do not know, you may find out by looking at the build output when doing a pristine build as that will also show the build of any child images).

[marvinwolf]

Hi,

i am using a Matter over THread example from connectedhomeip/examples at master · project-chip/connectedhomeip (github.com) as a basis.

So it is using radio. 

Do the network parts automatically get outsourced by zephyr, when i build for the NRF5340Dk?

If yes, why can i choose between building for the main core and building for the network core?

Thank you!

[Einar Thorsrud]

marvinwolf said:

i am using a Matter over THread example from connectedhomeip/examples at master · project-chip/connectedhomeip (github.com) as a basis.

So it is using radio. 

Then you net the network core. Note that I recommend you refer to the matter samples in the SDK, which are supported.

marvinwolf said:

Do the network parts automatically get outsourced by zephyr, when i build for the NRF5340Dk?

I am not sure what you mean. Can you elaborate? If you ask if the net core image (Multiprotocol RPMsg in this case) is automatically included, then yes. As a convenience it is automatically included as a sub image, as it is needed. You can read more under Multi-image builds.

marvinwolf said:

If yes, why can i choose between building for the main core and building for the network core?

You cannot. A  matter application cannot fit in the network core alone, so you have to build for the app core. And then you also need the multiprotocol_rpmsg sample on the net core to handle the radio.

[marvinwolf]

Einar Thorsrud said:

I am not sure what you mean. Can you elaborate? If you ask if the net core image (Multiprotocol RPMsg in this case) is automatically included, then yes. As a convenience it is automatically included as a sub image, as it is needed. You can read more under Multi-image builds.

Ah thank you, i thought that it would be necessary to "manually" move operations (like IEEE802.15.4 communication) to the network core, but instead that is done "automatically".

Einar Thorsrud said:

You cannot. A  matter application cannot fit in the network core alone, so you have to build for the app core. And then you also need the multiprotocol_rpmsg sample on the net core to handle the radio

That was meant in general. Im sure there is a usecase for some minimalistic application, that can run solely on the network core.

Thank you very much!

All questions clear!