nRF5340 Radio Notification callback alternative

[bihlori]

Hello!

I am developing an application for the nRF5340, and I am using split cores, so the controller is on the network core and the application is on the other core. I want to use Radio Notifications callback, but I saw that it is only possible if the application and the controller is on the same core, which is not possible in my case due to memory limitations.

Is there another way or workaround I could use to get radio notifications (or something similiar) working?

Thanks in advance.

[Einar Thorsrud]

Hi,

There is no ready made solution for radio notifications on the app core on nRF5340. There are potential ways to achieve it or somethign similar though, for instance ad decribed here or here.

[bihlori]

I have seen these, but because I don’t have the Bluetooth host built on the network core, I get build errors when calling the radio notification register function.

bt_conn_unref, bt_conn_get_info and other functions are undefined.

Maybe I am just misunderstanding the build process and I am not including something in the network core build? I am using a modified version of the hci_ipc sample because I am handling custom IPC commands as well.

[bihlori]

I update a GATT Characteristic with the given radio delay each connection interval that needs the precision by the radio notification callback. If I use a radio event (txready) I will be late with the updating, therefore there will be a connection interval delay.

[Einar Thorsrud]

I see. That will be difficult. As you write, radio notication requiers the host and controller to run on the same core and I am having problems seeing any other way to implement this.

If you have not come far in the development, perhaps it could be worth considering an nRF54L device instead? For isntance the nRF54L15 has ample memory, but does not have the complexities of a dual core device like nRF5340 and will let you use radio notifications.

[bihlori]

Could you elaborate on the IPC -> DPPI communication? How can I trigger a DPPI event from IPC?

[Einar Thorsrud]

Hi,

I am thinking about using the approach described here in the product specification. Alternatively, you can use the Zephyr icmsg IPC service that use this together with shared RAM under the hood (similarily to what is suggested here, though for a different usecase).

[bihlori]

Thank you!