DWM1001-DEV losing connection after 5 or 6 meters

waiting for 3 more DWM1001-DEV I’m still working with just 2 of them and I’m getting distance between them using dwm_loc_get API on the tag.

I noticed 2 strange things that I hope somebody can explain me:
[*]After 5 or 6 meters seems like they lose connection

[*]When they lose connection the distance value remain constant
6 meters is very low value compared to what said in datasheet and the fact that after loosing connection it keeps saying me a constant distance isn’t nice in my opinion.

Thanks in advance for the help


This value of 6 meters is fairly low indeed. Using the SHELL ouput command “les” with a initiator and a tag, we can consistently go over 50m. It does depend on the environment and reflection but 6 meters is small. Do you have good line of sight between the Device and the Tag ? A body would be enough to shield the signal.

Regarding you second point, it may be because if no new value is received then its sending the last value (this is what is done for dwm_get_pos). I’ll have to check that to be sure.

Let me know how it goes

Thank you

Let me know about the API.

I’m using SPI connection, not SHELL mode, but it shouldn’t change. I send 0x0c and 0x00 and then I parse the response.
The line of sight doesn’t seem too bad to go from 50 to 5m, but I’m going to try on open space soon. Do I have to take care about the directionality of the antennas? Is there any graph about it?

The Antenna performance in the section 6 of the doc below will give you an IDEA :

If you really get nothing after 6m, I’d expect to have line of sight issues. You can also go further to see it is improves. You may be in a fresnel zone for which there will be additional attenuation, potentially leading to very limited range.

Thank you,

Nice, thanks for the link. I was watching an older version of the datasheet.
So setting the modules vertically is better.

I’ll let you know after the tests.