nRF21540 is not compatible with nRF54L15

[Ziyao Zhou]

Hi,

Two month ago I have test nRF21540 and nRF54L15, they cannot word with each other.

However, I notice these days updated with

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/app_dev/device_guides/fem/index.html 

 

I have tried again but it still cannot work

My config is

#FEM general
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_BT_CTLR_TX_PWR_PLUS_8=y

My overlay is:

/ {
	nrf_radio_fem: name_of_fem_node {
	   compatible  = "nordic,nrf21540-fem";
	   tx-en-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
	   rx-en-gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
	   pdn-gpios   = <&gpio0 2 GPIO_ACTIVE_HIGH>;
		mode-gpios   = <&gpio0 3 GPIO_ACTIVE_HIGH>;
 };
}; //54L15

[Einar Thorsrud]

Hi,

The nRF54L15 and nRF21540 are compatible. Can you expalin in more detail how it is not working?

[Ziyao Zhou]

There is no change on the RSSI when I connect as I shown

[Einar Thorsrud]

Hi,

At first glance this looks good, but you need to use main as this supprort was added after the realease of SDK 2.9. Are you using main or a preview release? Which hash are you using?

[Ziyao Zhou]

I am using NCS 2.91

[Einar Thorsrud]

I see. That will not work, you can test with main (where it is supported and for which the doucmentation you linked to in the original post apply), or wait for the next release.

[Ziyao Zhou]

What does "main" means here, is it main.c? I am quite confused.

[Einar Thorsrud]

Hi,

I am sorry, I was not clear. I was refering to the "main" branch (what was previosuly often called "master"), i.e. the bleading edge, and not a released version. That should not be used for an end product, but if you want to work with the nRF21540 on the nRF54L15 that is one possibility as it is not currently supported in any released version. Another possibility is to use the 3.0 preview reelease. 

[Ziyao Zhou]

How could I get the 3.0 preview release? Is this correct?

[Einar Thorsrud]

Hi,

You can get it by following the instruction under Installing the nRF Connect SDK, particularily Get the nRF Connect SDK code. This explains both how ton install main and (preview) releases.

[Ziyao Zhou]

Hi

I just try to use v3.0.0-preview2, after compile the RTT will be OK, there is no error now.

However, I can not receive the ADV and cannot setup connection through both a central device or the nrRF Toolbox in the phone.

Could you please help me check this, the code isperipheral_uart_preview.zip

Thank you so much!