nRF21540 with nRF54L15

[Haresh05]

I want to add nrf21540 fem support in our nrf54l15 based application. I am currently using nrf54l15dk and nrf21540EK to achieve this.

Below is the .overlay and prj.config changes I have made and I am using NCS v3.2.0

&dppic10 {
	status = "okay";
};

&ppib11 {
	status = "okay";
};

&ppib21 {
	status = "okay";
};

&dppic20 {
	status = "okay";
};

&ppib22 {
	status = "okay";
};

&ppib30 {
	status = "okay";
};

&dppic30 {
	status = "okay";
};

/ {
	nrf_radio_fem: name_of_fem_node {
	   compatible  = "nordic,nrf21540-fem";
	   tx-en-gpios = <&gpio1 11 GPIO_ACTIVE_HIGH>;
	   rx-en-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>;
	   pdn-gpios   = <&gpio1 8 GPIO_ACTIVE_HIGH>;
		mode-gpios   = <&gpio1 9 GPIO_ACTIVE_HIGH>;
		tx-en-settle-time-us = <12>;
		rx-en-settle-time-us = <12>;
 };
};

CONFIG_MPSL_FEM=y
CONFIG_MPSL=y
CONFIG_MPSL_FEM_NRF21540_GPIO=y
CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y
CONFIG_MPSL_FEM_NRF21540_TX_GAIN_DB=20
CONFIG_MPSL_FEM_NRF21540_RX_GAIN_DB=13
CONFIG_MPSL_FEM_NRF21540_RUNTIME_PA_GAIN_CONTROL=y
CONFIG_BT_CTLR_TX_PWR_ANTENNA=20
CONFIG_NFCT_PINS_AS_GPIOS=y

I have made appropriate connection between these 2 boards. But I am seeing no change in RSSI values.

Can anyone let me know what else I am missing?

[Kazi Afroza Sultana]

Hello,

The device tree overlay file looks good but supply voltage configuration is missing. You can try to add supply-voltage-mv property in the fem node.

nrf_radio_fem: name_of_fem_node {
   compatible  = "nordic,nrf21540-fem";
   tx-en-gpios = <&gpio1 11 GPIO_ACTIVE_HIGH>;
   rx-en-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>;
   pdn-gpios   = <&gpio1 8 GPIO_ACTIVE_HIGH>;
   mode-gpios  = <&gpio1 9 GPIO_ACTIVE_HIGH>;
   supply-voltage-mv = <3300>;
   tx-en-settle-time-us = <12>;
   rx-en-settle-time-us = <12>;
};

[Haresh05]

Thanks for suggestion.

I added voltage config in device tree node and tried. Results are still same. No change in RSSI