Nordic Distance Toolbox - measurement at high precision

RE: Nordic Distance Toolbox - measurement at high precision

Susheel Nuguru — Fri, 06 May 2022 05:27:11 GMT

Yes, that is a good experiment, I think the direction of measurements and the offsets are important.

RE: Nordic Distance Toolbox - measurement at high precision

lubo — Tue, 03 May 2022 07:03:44 GMT

sorry I didn't mention that cb -> custom board, just an abbreviation for custom board

RE: Nordic Distance Toolbox - measurement at high precision

lubo — Tue, 03 May 2022 07:01:42 GMT

OK. I'll check those offsets too.

Meanwhile I did following test on our custom boards. I adapted FW to do only initiator or responder work only. It means board1 is advertising only and board2 is only scanning at synchronisation step. Then I changed FW on boards vice versa. And I see on chart two different distances measured. So as you say this issue probably has something to do with offsets and it depends which way the distance measurement is done (which board is initiator and which one is responder at ranging step).

RE: Nordic Distance Toolbox - measurement at high precision

Susheel Nuguru — Mon, 02 May 2022 12:34:45 GMT

what is cb in this context? seems like the cb offsets needs tuning, as ranging involving this device seems to have problem. Hard to say the reason without being able to replicate it on our end.

RE: Nordic Distance Toolbox - measurement at high precision

Susheel Nuguru — Mon, 02 May 2022 10:11:23 GMT

There could be issues with your customer HW, please double check if there are any issues with the antenna path or similar interference noise from close proximity network on the radio path towards the antenna. There are some calibrations that we do to tune away hardware specific offsets and you need to do the same for custom hardware.
In the file nrfxlib\nrf_dm\include\nrf_dm.h -> sruct nrf_dm_config_t -> member dist_offset_err, you can add an offset of the error that your hardware is showing with this solution. This offset will be different for different hardware and with custom hardware, you need to test and adjust these distance offsets that fits for your hardware

RE: Nordic Distance Toolbox - measurement at high precision

lubo — Mon, 02 May 2022 07:30:29 GMT

Yes the same app is running on both of them. Problem occurs in case of ranging with the cb to cb, cb to ublox. Only case ublox to ublox is doing ranging well.

RE: Nordic Distance Toolbox - measurement at high precision

Susheel Nuguru — Fri, 29 Apr 2022 10:09:49 GMT

not really sure. Are you running the same application on your custom board and ublox?

RE: Nordic Distance Toolbox - measurement at high precision

lubo — Thu, 28 Apr 2022 10:54:58 GMT

Update:

I tested the sample on ublox NINA-b302 modules. I'm not observing the problem. Seems like there is a problem on our custom boards. Any ideas what could be a problem on it?