adding nrf21 FEM to new 53 board

RE: adding nrf21 FEM to new 53 board

Håkon Alseth — Wed, 08 May 2024 08:20:25 GMT

Hi,

It should go in the network core image, which is "hci_rpmsg" for NCS v2.4 or older, while it is named "hci_ipc" in ncs v2.5.x and newer.

If you look at this answer, it shows how to verify that your configurations have been applied properly: RE: Using nrf5340dk with the nrf21540 EK

Kind regards,

Håkon

RE: adding nrf21 FEM to new 53 board

Mustafa — Tue, 07 May 2024 17:03:17 GMT

Thank you Håkon!

Just for clarification, to add nrf21 fem we need only to add the gpio declaratin and radion node only in nrf5340_cpunet.dts right?

after that I noticed some examples where CONFIG_MPSL_FEM_xxxxx settings are placed either in main proj.conf or in hci_rpmsg ? which one is the correct file for those settings?

Besides that I got a lot of warnings when I enabled gpio mode using CONFIG_MPSL_FEM_NRF21540_GPIO , is that the correct config to do that or I need to add more dependencies?

Best regards

RE: adding nrf21 FEM to new 53 board

Håkon Alseth — Tue, 07 May 2024 11:36:38 GMT

Hi,

Here is a thread covering the same question(s):

Using nrf5340dk with the nrf21540 EK

[quote user=""]CONFIG_MPSL_FEM_NRF21540_TX_GAIN_DB_POUTA=20[/quote]

You should keep this value to the default, as described here:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/device_guides/working_with_fem.html#setting-the-fem-output-power

[quote user=""]CONFIG_BT_CTLR_TX_PWR_ANTENNA=127 [/quote]

This line shall be equal to your expected/wanted output power.

If you are targeting your product for europe, please note that +10 dBm is the max, as stated here in this comment:

RE: Using nrf5340dk with the nrf21540 EK

Kind regards,

Håkon