[Ovmsdev] Strange issues with Car GPS accuracy.

[Michael Balzer]

Michael,

if the module affects your car's builtin navigation system, I think that 
points to some EM interference. While the module has passed the EM tests 
for certification, it still emits some EM noise, and some devices are 
more sensitive to this than others. There also may be a satellite outage 
affecting Australia currently, that adds to the sensitivity.

You could try to selectively switch off Wifi and the modem when the 
issue occurs, to see if one of these cause it.

If not, you could try reorienting and replacing the module in the car, 
especially if it's very close to the nav system's GPS antenna.

Regards,
Michael


Am 27.05.23 um 10:07 schrieb Michael Geddes:
> Latest: I changed the startup vehicle to None and turned off the 
> mobile.  Still getting drifting vehicle GPS until I unplug the OVMS.  
> Hardware issue? Does anybody have any clues?
>
> Michael
>
> On Sun, 21 May 2023, 11:41 am Michael Geddes, 
> <frog at bunyip.wheelycreek.net> wrote:
>
>     Hi all,
>     I'm having a bunch of weird things going on which seem correlated
>     to having the OVMS running.  I'm not convinced of causation yet.
>
>     My car's Nav system is drifting out majorly (like by >100m) and
>     then seems to stay out.  This causes major distractions as the nav
>     system keeps giving me warnings about going down one-way roads and
>     it makes the navigation 'interesting' to use.
>
>     I also noticed that Android Auto location was frozen in one place,
>     so I assumed this was coming from the car - or meant to be
>     anyway.  I reduced the polling rate (new work I'm doing) slightly
>     and this freezing no longer happens. (To 3 speed queries per
>     second).  But the drifting out on the Navigation  still happens...
>     but then not on AA!? Very very weird.
>
>     If I unplug the OVMS from the OBD port (as I'm driving) it seems
>     to (but not immediately - after a minute or so) correct itself. 
>     It's hard to confirm this is directly resulting .. but it seems to be?
>
>     I turned off my ECU2OBD which should mean that it is resorting to
>     1 per second POLL with a low throttle value. I'll run with some
>     logs to make sure this is what is happening.. but it still seems
>     that this hasn't stopped this issue from happening.
>
>     I've tried turning the GSM power off. No result.
>
>     Another note: I seem to have stopped getting anything near regular
>     updates from the OVMS GPS. Every now and again it gets a
>     successful change come through.  Still working on diagnosing
>     that.. maybe it's related?
>
>
>     Any thoughts / help would be useful.
>
>     //.ichael
>
>
>
>
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-- 
Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
Fon 02333 / 833 5735 * Handy 0176 / 206 989 26

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