[ncs 2.7.0] Simple GPIO to control SKY85303 FEM

[Gavin]

Hi，

I have a custom board with nRF52833 and sky85303-21 FEM. To control the FEM, I have added the following code to my app.overlay file and enabled simple GPIO configs.

/ {
    nrf_radio_fem: name_of_fem_node {
       compatible = "skyworks,sky66112-11", "generic-fem-two-ctrl-pins";
       ctx-gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
       crx-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
    };
 };
 

CONFIG_MPSL=y
CONFIG_MPSL_FEM_ONLY=y
# CONFIG_MPSL_FEM_LOG_LEVEL_DBG=y
CONFIG_MPSL_FEM_SIMPLE_GPIO=y
CONFIG_GPIO=y

Build issue:

I’m not sure if there are any other configurations that need to be enabled. Could you please advise if there are additional settings I should be aware of?

My question:

I noticed that the documentation primarily discusses the SKY66112-11. I wanted to confirm whether I can use this directly, or if I need to develop a separate driver for the SKY85303-21.

Thanks,

Gavin

[Vidar Berg]

Hello Gavin,

The SoftDevice controller depends on services from the MPSL library, but these services are disabled when the CONFIG_MPSL_FEM_ONLY symbol is enabled. To fix the build error, please remove the 'CONFIG_MPSL_FEM_ONLY=y' line from your project configuration file.

Best regards,

Vidar

https://github.com/nrfconnect/sdk-nrf/blob/e2152662f8c1a8954804670417926d07c82037dc/subsys/mpsl/Kconfig#L9 

[Gavin]

Hello Vidar,

Thanks for your reply.

It works well.

CONFIG_LOG=y
# CONFIG_LOG_BACKEND_UART=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_RTT_CONSOLE=y
CONFIG_UART_CONSOLE=n

CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME="PA_LNA_TEST"

CONFIG_MPSL=y
CONFIG_MPSL_FEM=y
CONFIG_MPSL_FEM_SIMPLE_GPIO=y

/ {
   
    // SKY85303-21
    nrf_radio_fem: sky_pa-lna {
       compatible = "generic-fem-two-ctrl-pins";
       ctx-gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
       crx-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
       ctx-settle-time-us = <10>;
       crx-settle-time-us = <10>;
       tx-gain-db = <4>;
       rx-gain-db = <4>;
    };
 };
 
 

&radio {
    fem = <&nrf_radio_fem>;
};