MPSL with two chained FEMs on nRF5340

[jbreal]

Is it possible to use configure MPSL to use multiple FEMs? I see that you can configure it to use a simple GPIO interface, which works fine for a single FEM with fixed gain. But what should I do if I have two FEMs? One is builtin to the uBlox module we're using, and one is external, on our own board. Both have the same sort of GPIO interface. I still don't understand when MPSL decides to bypass or not. Assuming I decide how much gain I want out of the FEM, I still would need MPSL to provide me a callback or something so that I could control multiple IO pins when switching between TX and RX. It seems like this is not possible, or maybe I'm confused? I'm using nRF SDK 2.6.0 btw.

[JONATHAN LL]

Can you share a diagram of how this is connected to each other? I am struggling a bit to see how it is connected to one another. 

And are you using the nRF21540 as a FEM or something else? 

Regards,
Jonathan

[jbreal]

We are using a uBlox NORA-B12 module, which has a SkyWorks SKY66405 builtin, and then we are also planning on using AoA, so we have an RF mux, and then an FEM (also SKY66405 ) at the end of each of those.

.                   Ant   +----SKY66405--RF1
.                  Demux  +     |
.  ____________     _     |  +--+
. |            |RF / |----+  |
. |   SKY66405-|---  |-------|-SKY66405--RF2
. |         |  |   \_|----+  |  |
. | nRF5340-+  |    |     |  +--+
. |____|_______|    |     |  |
.   |  | ANTSEL     |     +--|-SKY66405--RFn
.   |  +------------+        |  |
.   |                        |  |
.   +------------------------+--+
.                    CRX/CTX/CPS

[PaKa]

Is this for an AoA receiver? That is NOT supported with the SoftDevice Controller Subsystem which is the only option that uses MPSL so if this is the case, then the answer is "Not Applicable".

For AoA receiver you need to look at the nRF Connect SDK 2.2 and using the Zephyr controller. If this is to get LNA functionality then I would check that the LNA will work with the waveforms coming out when you switch the antennas.

[jbreal]

The application would be using Bluetooth and ESB via the use of the MPSL library in the nRF SDK 2.6.1. And yes, the intent would be to use AoA as well.

[PaKa]

You may do all those things on the transmitter side.

On the receiver side you have to select either ESB or AoA, you will not be able to run both at the same time.

This as AoA reception is only supported by the Zephyr controller in nRF Connect SDK 2.2 and this doesn't support running ESB.

If you want ESB then you need to use the SoftDevice Controller Subsystem and this does not support AoA receiver funtionality.