nRF5340 Audio DK with nRF21540 FEM Shield Configuration

[iain_h]

Hi there,

I have some nRF5340 Audio DKs, and have got the example nRF5340_audio application working fine. I am using VS Code on Windows for this, and SDK 2.4.0.

What I am trying to do now is add a FEM for range extension, and I have nRF21540-EK Shields for this purpose. However, I am running into trouble with the Kconfig options in trying to get this to work correctly. I have been following the documentation here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/nrf5340_audio/README.html#adding-fem-support

However, I can't seem to configure everything to allow the FEM support (ideally GPIO + SPI). I have added -DSHIELD=nrf21540_ek_fwd to the build configuration, and have also enabled MPSL as instructed (which required the MCU selection of NRF5340_CPUNET_QKAA as far as I can tell). But, the FEM type options are still greyed out in Kconfig, which depend on "MPSL_FEM". When I check this option, "MPSL_FEM" is also greyed out, and depends on "MPSL" (which is enabled) and "MPSL_FEM_ANY_SUPPORT".. however I can't find this option anywhere. Please see below screenshots of these options mentioned:

Can you tell me what I could be missing?

Thanks.

[Karl Ylvisaker]

Hello,

Thank you for your extreme patience with this. We are currently in the national summer holiday period here in Norway, and so the response time unfortunately is much longer than average. I apologize for the inconvenience.

Could you try to completely delete your last build folder, and then rebuild the project?
Please then share the log output from this build here in DevZone (using the Insert -> Text option), so that I may take a look.

For good measure, could you also confirm which LE Audio controller version you are using?

Once again I would like to thank you for your extreme patience with this.

Best regards,
Karl

[iain_h]

Hey Karl,

No worries at all, I should have realised you guys would be on summer holidays - I am in the southern hemisphere so it slipped my mind!

It is OK, the team in Sydney saw my post and have been in contact with me, so I am working through this with them.

Thanks again,

Iain.

[Karl Ylvisaker]

Hello again, Iain

I am glad to read that the Sydney team is helping you with this, but I would once again like to apologize for the delay you saw in the original response rate - this is far higher than our acceptable response time.

Please do not hesitate to open up a new ticket if you should encounter any other issues or questions in the future! :) 

Best regards,
Karl

[Frog]

I find myself in a similar situation - I have an nRF5340 and an nRF21540 FEM.  I've added an overlay for the network processor and added the pin configurations for the SPI and GPIO pins that control the FEM, but CONFIG_MPSL_FEM_ANY_SUPPORT isn't set.

Are you please able to share what the Sydney team suggested?

[Karl Ylvisaker]

Hello Frog ,

This case is a little old, so in case iain does not come back with a reply to you I would recommend that you open a separate ticket so that we may help you with the issue you are seeing.
If you do this, please make sure to include which nRF Connect SDK version you are working with, and the relevant modifications you have made to increase the TX power.

Best regards,
Karl

[Frog]

Thanks I'll do that if I don't make significant progress on my own