MPSL FEM Support Build Issues on NCS1.7.0

[TylerS]

Hello,

I am having some build issues when attempting to add support for a Skyworks FEM to our application built with NCS 1.7.0 for a NRF52820 target. Our board file is based on the nrf52833dk_nrf52820 board file provided in the SDK. 

I have added the following to our proj.conf:

CONFIG_MPSL=y

CONFIG_MPSL_FEM=y

CONFIG_MPSL_FEM_SIMPLE_GPIO=y

I have added the following to our root devicetree node:

     nrf_radio_fem: pa_lna {

 

         compatible = "skyworks,sky66112-11", "generic-fem-two-ctrl-pins";

 

         ctx-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;

 

         crx-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;

 

     };

Upon building I get an error in mpsl_fem.c that says: 'mpsl_fem_simple_gpio_interface_config_t' {aka 'struct <anonymous>'} has no member named 'ppi_channels'; did you mean 'dppi_channels'?

Tracing it down it seems that for some reason  #if defined(NRF52_SERIES) is false inside of mpsl_fem_config_simple_gpio.h

Am I doing something wrong with my build configuration or project configuration? Or is there some inherent problem with this SDK version and trying to turn on this feature. 

I have modified mpsl_fem_config_simple_gpio.h so that it doesn't check the NRF52_SERIES define. This builds and it seems that the fem is operating as expected. Of course we would like to find a solution to the issue so that we do not need to modify this file. 

Thank you

[TylerS]

Hi Torbjørn,

Thank you for the response and the example project. That one built successfully for us and we looked further into the differences between that and our project.

We have found the issue. When CONFIG_ARM_MPU is set to n it causes the problem with the NRF52_SERIES define. I am not entirely sure why that is or if that is expected behavior. We had copied CONFIG_ARM_MPU=n from a proj_minimal.conf in order to save application size on the 52820. With that removed it is building fine now. 

Thank you for your help. We can close this case.

[ovrebekk]

Hi Tyler

Good to hear that you found the issue

It is odd that disabling CONFIG_ARM_MPU would affect the NRF52_SERIES define. If the developer has some input on this I will let you know. 

Best regards
Torbjørn

[ovrebekk]

Hi Tyler

The developer didn't know of any dependencies between CONFIG_ARM_MPU and the NRF52_SERIES define. 

If you give us the full build log we can take a look, otherwise I will consider the case resolved

Best regards
Torbjørn

[TylerS]

Hi Torbjørn,

The only thing I can find is that the CONFIG_ARM_MPU is also set in the nrf52833dk_nrf52820_defconfig which is also where the following defines are:

CONFIG_SOC_SERIES_NRF52X=y

CONFIG_SOC_NRF52820_QDAA=y

CONFIG_BOARD_NRF52833DK_NRF52820=y

Not sure if this is how they are interacting somehow.

Anyways thank you for your help.

ovrebekk said: