Unable to add FEM support on nRF21540

[Rajeev K R]

Hi,

 I am unable to add FEM support to nRF21540, Running on ncs 2.6.0 Vscode Zephyr. I am using BLE Peripheral_hr sample. I was following this doc.

This is my error

c:/ncs/toolchains/cf2149caf2/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd.exe: modules/nrf/subsys/bluetooth/controller/lib..__nrf__subsys__bluetooth__controller.a(hci_driver.c.obj): in function `mpsl_work_submit':
C:/ncs/v2.6.0/nrf/include/mpsl/mpsl_work.h:49: undefined reference to `mpsl_work_q'
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

I even tried manually copying the mpsl library to my code, made some cmake edits and tried building, but reached at the same error.

this is my .prj.config.

CONFIG_BT=y
CONFIG_LOG=y
CONFIG_BT_SMP=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DIS=y
CONFIG_BT_DIS_PNP=n
CONFIG_BT_BAS=y
CONFIG_BT_HRS=y
CONFIG_BT_DEVICE_NAME="Zephyr Heartrate Sensor"
CONFIG_BT_DEVICE_APPEARANCE=833
# Enable FEM and MPSL
CONFIG_MPSL=y
CONFIG_MPSL_FEM=y
CONFIG_MPSL_FEM_NRF21540_GPIO_SPI=y
CONFIG_FEM_AL_LIB=y
CONFIG_FEM=y
# CONFIG_MPSL_FEM_ONLY=y

In my build configurations, I have selected the board as nrf21540_nrf52840.

I need to know what am i doing it wrong. Please advice. Let me know if you want more details

[Amanda Hsieh]

Hi, 

It would enable the required configs for the unmodified sample if you build for nrf21540dk_nrf52840. It doesn't need extra config settings so that you can remove them. 

Regards,
Amanda H.

[Rajeev K R]

Hi Amanda,

Amanda Hsieh said:

It would enable the required configs for the unmodified sample

so If I dont need to add these in my code? 

# Enable FEM and MPSL
CONFIG_MPSL=y
CONFIG_MPSL_FEM=y
CONFIG_MPSL_FEM_NRF21540_GPIO_SPI=y
CONFIG_FEM_AL_LIB=y
CONFIG_FEM=y

I just have to build the code with nRF21540_nrf52840 board?. 

[Amanda Hsieh]

Rajeev K R said:

so If I dont need to add these in my code? 

No. 

Rajeev K R said:

I just have to build the code with nRF21540_nrf52840 board?. 

yes, you can check the .config under build/zephyr.