NRF7002 Radio test RX_CAP 2 trigger

[Julianstj]

Hello,

I'm testing the IQ feature of the radio test. According to the documentation on https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/wifi/radio_test/sample_description.html  , the last IQ test documentation for RX_CAP 2 , it should only trigger off WLAN packet.

I put a NRF7002 DK in an RF chamber and ran the wifi scan test application as well, and it saw no frames and no detected devices.

WiFi scan application building and output:

nrf\samples\wifi\scan

west build -b nrf7002dk_nrf5340_cpuapp -- -DCONFIG_WIFI_MGMT_RAW_SCAN_RESULTS=y

Scan request done
Scan requested
Scan request done
Scan requested
Scan request done
Scan requested
Scan request done
Scan requested
Scan request done

However, when I run the radio test application with rx_cap 2 similar to the documentation, it does dump IQ samples. I did init 144 and init 1 to try both 2.4GHz and 5GHz wifi bands, and both triggered the IQ dump.

radio test build and run

west build -b nrf7002dk_nrf5340_cpuapp

uart:~$ wifi_radio_test rx_capture_length 10000wifi_radio_test rx_cap 2
************* RX capture data ***********
FD5FDF
036022
FC3030
043FCC
FDFFB7
FC2038
048013
015FE0
00BFD5
039FDE
03D011
022012
005FCE
010FC9
01BFE7
FF5FCC

I would expect that, a device in a sealed RF chamber, with no other boards, and wifi scan showing nothing, that the IQ dump shouldn't trigger. If I look at the IQ dump frequency content, it does show an arc around the center, which seems to point towards it trying to detect something. Is this a known behavior of RX_CAP 2 operation?

Thanks!

[Håkon Alseth]

Hi,

 

My deepest apologies for the long wait.

I just got feedback from the developers that a fix is on-going, but unfortunately not released, as the fix has some negative side-effects:

Default thresholds in our detection logic are such that there is minor probability for false detection. These thresholds are chosen intentionally. This is leading to capture to happen when there is no WLAN signal present. For radio test application, we modified thresholds so that capture does not happen when no WLAN signal is not present. So, we have a solution for the problem reported by customer. However, this has shown up a limitation in handling of this command for negative test scenario (i.e., capture timing out).

I am unfortunately not able to provide a more detailed timeline of when this fix is ready, but if this is a high priority for your evaluation/development, you can send me a direct message with your location, and I will provide you information to your local RSM.

 

Kind regards,

Håkon

[Julianstj]

Hi Håkon, ok this is great, please let me know when a new version is ready to test. thank you!

[Håkon Alseth]

Hi,

 

My deepest apologies for the long waiting time.

The fix, highlighted in this PR https://github.com/nrfconnect/sdk-nrfxlib/pull/1399, is now merged to the main-branch.

There is unfortunately no tag release where this is currently present, meaning that you will have to use the main branch to test this specific fix.

Here's way to update your ncs installation to main:

* Open up a command line with the NCS environment set

* change to folder \path\to\ncs\nrf

* Issue these git commands:

git fetch origin
git checkout origin/main
west update

 

Kind regards,

Håkon