Nordic Distance Measurement , precision vs Webinar?

[Olfox]

Hi Nordic :)

I followed last week the nice Webinar on topics : Nordic Distance Measurement library

I'm using two nrf52833 DK, and run on both nrf_dm sample zephyr project.

I have to admit that i was really enthousiast by the results of the high precision method.

But i have to admit that by running the example i can't achieve same result than you.

Both stability and precision in direct path indoor environnement are not really what i expect.

By waiting that i develop a small tool to log my results and share with you real data,

1) is there an option in the example code  nrf_dm that i could change to put at maximum the precision even if it cost time ans flash size.

I only found in peer.c:    #define DEFAULT_RANGING_MODE    DM_RANGING_MODE_MCPD        that should be better than RTT on short range.

2) Durring webinar you talked about nrf_dm_high_precision_calc that i couldn't find in the code,  only in API documentation. Is it possible to quickly adapt nrf_dm demo to use it ?

I'm interrested in measuring distance from 50cm to 10m and both product can be in bag for exemple.

I still hope i could reach the precision and stabilty with this technic ! 

Thanks a lot !

[Olfox]

Hi, 

Here are my first measurement, with two nrf52833 DK at 1.5m from each other, in a desk environement.

Here measure is close to 3m, 3m50. When i'm tping on my keyboard ( so my arm are in between and my body close to it but not in the direct path), it jump to 7m50.

I will do others measurements farer and closer , with and without obstacle.

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Questions:

1. First, should i devide the measurement by two ? It seems there is a x2 coefficient.

2. How to use high precsion algorythmes to compare results?

3. I see a function used in the main.c:        service_azimuth_elevation_simulation();

What is it used for please ?

4. When i will deploy on my custom board, whitch antenna parameter should i have to adapt and how to proceed please ( empiric technic like: characterize by measurement and test all the trimmig code available, and choose the best?)

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Thank you, i hope t be able to have this distance measurement working fine soon.

[Kenneth]

We don't understand what may be the problem here, are you able to test with various distances and orientations of the boards to see if you get more accurate results?

There is no samples that you hi-prec at the moment, this will come eventually.

Kenneth

[Olfox]

Hi Kenneth,

Probleme is that i have 1m50 between the two board, and it print in mean 3m44 so the double of the distance. 

Second issue, here we are in good condition without anything in between. If i place my body, it jump to 7m of distance. 

Can you answer other questions please in the order ?

thanks a lot.