How to get RSSI in the direction_finding_connectionless_rx example on nRF52833?

[Sener]

Hi,

I want to simply get RSSI at each scan in the connection less example (direction_finding_connectionless_rx).
I have running two nRF52833-DK. One is flashed with RX and the other with RX example.

I'm using the nordic NCS SDK v1.8.0 with softdevice s140 v7.3.0.

The devices are communicating to each others nice and easy. But, RSSI readings at each scan show a constant value (-127)

When I debug it (using RTT Viewer and Debug terminal), I get this;

RSSI looks always -127.

I can only see some different RSSI readings during initial talk between the two devices (anchor and tag)

Any input greatly appreciated.

[Simonr]

Hi

First off, the nRFConnect SDK does not use SoftDevices like the S140 (they belong in the nRF5 SDK), as the nRFConnect SDK rather uses a SoftDevice controller, so if you've tried mashing the SoftDevice onto an nRFConnect SDK project that might be causing trouble.

It seems to state that the TX power is 127 as well, which seems fishy to me. 

One is flashed with RX and the other with RX example.

I assume you mean that one is flashed with the DF connectionless TX (beacon) sample, and one is flashed with the DF connectionless RX (locator) sample.

I think what is happening is that you're mixing up AoA and AoD modes which for some reason makes the RSSI off on the receiver side. Please try setting up the projects again and read the setup instructions carefully when doing so.

Best regards,

Simon

[Sener]

Hi Simonr,

Thank you very much for your answer. I haven't noticed that you've replied until I find it in my e-mail box instead of here under my entry.

Yes, I meant there RX and TX. I've already corrected in my entry. 

In fact that, the setup and everything were relatively easy. I have started to setup thing with the help of "nRF Connect for Desktop v3.10.0" => "Toolchain Manager" => Open Segger Embedded Studio. it was more or less Next by Next.
I am not sure if I did anything with Softdevice.
And then I've pick the project(s) and I could build the project(s) flawlessly.

I have also made a few changes in the config files only for RTT Viewer with J-Link.
And I added a line in the CMakeList.txt => SET(OVERLAY_CONFIG "overlay-aoa.conf")
I did those changes for the both RX and TX examples. But not sure if I must use this OVERLAY_CONFIG for RX version as well. Because, in the ReadME file, it doesn't say so.

Here is where I pick the projects and build right away.

So far, I have done/tried whatever I could gather around in the devzone and manuals. But not everything make sense and you have to figure out yourself. For example, there was a saying like that; "To build this sample with angle of arrival mode only, set ``OVERLAY_CONFIG`` to :file:`overlay-aoa.conf`." This cost me a lot of time to figure out what it means exactly.
Finally I found that it meant you have to write a line in the `CMakeLists.txt` file:
=> SET(OVERLAY_CONFIG "overlay-aoa.conf")

However, unfortunately, I have still the same result, no sensible RSSI and tx-power as you pointed.

I've also seen some others in the devzone. Their output was also similiar to mine. I think I am not alone with that.
This entry shows the same issue (although it was not the main complain in there);
https://devzone.nordicsemi.com/f/nordic-q-a/83857/ncs-1-8-direction_finding_connectionless_rx-aoa-can-t-work

Do you have any further idea for me?

Thanks.

Best regards,

Sener