Documentation on nrf5340 network core

[ChristiaanP]

Hi,

I'm building an application for the nrf5340 in rust and I want to be able to use the bluetooth LE audio functionality. For this I have two questions:

1. How can I build the network core software separately so I can use that with my own application core FW
2. Is there some documentation on how to communicate to the network core and use it for the LE audio usecase.

I'm currently interested in using it as a CIS server.

Thanks in advance.

[Edvin]

Hello,

We don't have anything to provide when it comes to Rust, unfortunately. What we do have is the nRF Connect SDK, with it's softdevice controller (BLE stack). 

If you flash any of the BLE samples from nRF Connect SDK to the nRF5340 DK, it will automatically flash the SoftDevice Controller to the network core. If you like, you can then later flash whatever you want to the application core, and the network core will still have the softdevice controller. (and you can keep a copy of the networks core .hex file, so you don't have to go through the step of flashing the appilcation core twice).

After that you can use the network core as an BLE HCI core, which is a standardized BLE API (used by Bluetooth dongles for computers). 

But I have no idea how to mix Rust into this. I have heard of it, but never used it.

Best regards,

Edvin

[ChristiaanP]

Thanks, that should get me most of the way I think. How is the communication build between the application core to the network core. I'm fully aware that Rust is uncharted territory and I'll have to build it myself. I just need to know how to talk to the network core and I'll figure out the rest.

[Edvin]

You can check out the IPC sample. This is the communication used between the cores. It is found in NCS\nrf\samples\ipc\ipc_service.

[ChristiaanP]

Is the source code for the network core also available somewhere? I'm hoping to make a version that only supports our usecase to minimize the resources (and power) needed.

[Edvin]

Our SoftDevice controller (Bluetooth Low Energy stack) is not open source, unfortunately. There is an alternative to use Zephyr's open source Bluetooth Low Energy stack, but it will be difficult to qualify this with Bluetooth, because this stack in it self is not certified. So that would be more usefull for educational purposes. The power is quite optimized using our SoftDevice controller, so I don't think you will see the same low current consumption if you are using the Zephyr Bluetooth LE stack. 

Best regards,

Edvin