Interfacing nRF21540 with nRF52832 Using nRF Connect SDK

[Embel_Tech]

Hello Team,          

          I am currently working with the nRF52832 and using the nRF Connect SDK (NCS) with toolchain version 2.9.1. I would like to interface the nRF21540 RF Front-End Module with the nRF52832.

      However, based on the documentation, I could not find any specific examples or detailed steps for this particular interface. Could you please provide reference documents or guidance on how to properly interface the nRF21540 with the nRF52832?

   If possible, I would appreciate a step-by-step outline including any dependencies or configuration requirements necessary to get the setup working correctly with the nRF Connect SDK.

  Looking forward to your support.

[Hieu]

Hello Embel_Tech,

Please find documentation on how to work with the nRF21540 FEM here: Developing with Front-End Modules.

Hieu

[Embel_Tech]

Thanks for your response, will check.

[Embel_Tech]

Hi Hieu,

     I am working with the nRF52832 as a central device using the nRF5 SDK 15.0.0, and we are trying to interface the nRF21540 (EK) board with the nRF52832 specifically for RX gain enhancement only.

     According to the nRF21540 documentation, the RX gain is fixed at +13 dBm. Since this is a central device, we do not intend to use TX control. for RX gain Our hardware setup is as follows:

nRF52832 Pin	nRF21540 EK Pin
VDD	VDD
GND	GND
P0.03	RX_EN
P0.04	PDN (P10.2)

     The antenna is connected to ANT1 on the nRF21540, and the antenna output from the nRF52832 is connected to the TRX input on the nRF21540 EK.

Software Implementation:

• Configure RX_EN and PDN GPIOs as outputs and keep them set high continuously. Because the nRF52832 is running in continuous scanning mode as a central device.

Observed Behavior:

    We tested device advertising at approximately -40 dBm RSSI. When the central and peripheral devices are very close (around 40-50 cm), scanning works successfully. However, when the distance increases slightly, the device is not detected/scanned.

Questions:

1. Is the interfacing of the nRF21540 with the nRF52832 using nRF5 SDK 15.0.0, as described above, correct? Are we missing any critical hardware or software configurations?

2. What could be the possible reasons or missing steps that might cause the range extender to not function as expected?

Any insights or suggestions would be greatly appreciated.

Thank you!