[nRF5340 + nrf7002] wifi-fund-main: lession 2 excersice bt_hci_driver open failed with -11

[DDYD1]

Good day.

I am currently verifying BT of nRF5340 on a custom board using nrf7002 with nrf5340.
My custom board is based on the nRF7002DK, and the pin connections are based on the nRF7002DK.
To check the BT connection of nRF5340 and WIFI connection of nRF7002 at once, I am using the example of WIFI connection using BT in lesson 2-exercise 3 of DEV ACADEMI.
I succeeded in bulid the example, but when I tried to run it, I got an error.

*** Booting nRF Connect SDK v2.7.0-5cb85570ca43 ***
*** Using Zephyr OS v3.6.99-100befc70c74 ***
[00:00:02.191,589] <err> bt_hci_driver: bt_ipc_open: Endpoint binding failed with -11
[00:00:02.191,619] <err> bt_hci_core: bt_enable: HCI driver open failed (-11)
[00:00:02.191,619] <err> Lesson2_Exercise3: main: Bluetooth init failed (err -11).

From this error history, i deduced that the BT module failed to connect with the network core.
However, i still don't know the exact cause of the error and how to fix it.
Any help would be greatly appreciated by me.

Thank you.

[Simonr]

Hi

The error seems to come from the bt_ipc_open() where it fails to bind the endpoints. The error message indicates a "try again" error, so likely something in your application is not ready on your board when calling this function. Have you made sure the network core on the nRF5340 is flashed with the correct firmware on your end?.

Please note that the supported SDK versions currently for the Wi-Fi fundamentals course is the nRF Connect SDK v2.5.0-2.6.1. I see that you're using nRF Connect SDK v 2.7.0 which is likely what's causing this issue in the first place. We still haven't updated this lesson to match the latest SDK releases I'm afraid.

As per the nRF Connect SDK v2.7.0 migration guide, all samples and applications built for multi-core SoCs were migrated to use the IPC radio firmware as the default image for the NET core on the nRF5340. The samples previously built for those cores are no longer used in the default builds. HCI IPC shuuld be similar to lesson 2 - exercise 3, so you can check that out if you're determined to work on NCS 2.7.0. The easiest fix would be to move back to v2.6.1 though.

Best regards,

Simon