DFU not possible after enabling BT_SMP (for wifi provisioning)

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

Sigurd Hellesvik — Fri, 22 Dec 2023 13:09:20 GMT

Hi,

I will continue helping in this case.

First, I will try a blind guess:
Try CONFIG_MCUMGR_TRANSPORT_BT_AUTHEN=n?

Regards,
Sigurd Hellesvik

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

qrasmont — Wed, 20 Dec 2023 15:16:09 GMT

Sure, I added the pair callbacks but that does not change the behavior I described above.

Ideally I would like to have DFU working with the same setup as the provisioning sample meaning no passkey required.

devzone.nordicsemi.com/.../dfu_5F00_issue_5F00_smp2.zip

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

Amanda Hsieh — Wed, 20 Dec 2023 14:47:28 GMT

The provisioning sample demonstrates the pair without the passkey setting. seems your code missed the pair callback https://github.com/nrfconnect/sdk-nrf/blob/3b4fdd9eb4c980f5320ad241e93a89957fb23e9a/samples/wifi/provisioning/src/main.c#L172-L190

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

qrasmont — Tue, 19 Dec 2023 14:41:39 GMT

Here is an updated sample with the proper setup for SMP.
Remove the setting of the passkey_display callback at line 73 of main.c and the package upload should be unsuccessful after pairing.

devzone.nordicsemi.com/.../dfu_5F00_issue_5F00_smp.zip

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

qrasmont — Tue, 19 Dec 2023 14:36:16 GMT

I forgot that I also had attempted to send the package using the "nRf Connect" app and it failed as well so guess any issue occurring here is not specific to the device manager app.

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

qrasmont — Tue, 19 Dec 2023 14:32:27 GMT

Hi Amanda,

Thanks, I understand why some additional setup is needed when enabling CONFIG_BT_SMP.
When adding the necessary callbacks shown in the doc to the sample I provided, everything works as expected.

Coming back in my code base where I use the wifi provisioning service, I think I identified the issue.

In the provisioning sample there is no passkey_display callback set for in bt_conn_auth_cb. If I set a callback I can successfully send the DFU package after pairing.

But this callback can be NULL for, as stated in the documentation, devices that are not able to display a passkey.
So is it that pairing without passkey is not handled properly by the device manager app ? Or maybe a limitation of my phone/Android version ?

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

Amanda Hsieh — Mon, 18 Dec 2023 21:25:31 GMT

Hi,

The CONFIG_BT_SMP would enable support for the Security Manager Protocol (SMP), making it possible to pair devices over LE. It also needs the setting with the code. Please take a look https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/lessons/lesson-5-bluetooth-le-security-fundamentals/topic/blefund-lesson-5-exercise-1/ for the setting.

-Amanda H.

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

qrasmont — Fri, 15 Dec 2023 15:40:20 GMT

Sure the DFU configuration is based on this sample. The main difference being that my config accounts for the fact that the external flash is connected over SPI and not QSPI on the nrf7002 dk.

I've made the following project with the minimal setup to reproduce the issue I have described.
With CONFIG_BT_SMP=y at line 54 of the prj.conf the issue should be reproducible (immediate disconnect after pairing).
Comment this same line and the image should uploaded properly.

devzone.nordicsemi.com/.../dfu_5F00_issue.zip

Build command: west build -b nrf7002dk_nrf5340_cpuapp

RE: DFU not possible after enabling BT_SMP (for wifi provisioning)

Amanda Hsieh — Fri, 15 Dec 2023 14:56:02 GMT

Hi,

Could you provide the details about implementing the DFU?

Is it possible to provide the project?

Regards,
Amanda H.