[Ovmsdev] Strange issues with Car GPS accuracy.

[Michael Geddes]

Yeah I was definitely getting BUS conflicts at one point but I think I
might have solved the problem on that. I also unravelled some of the cords
and that seems to have settled things a bit. Maybe it was generating some
noise on the bus?

I'll do some more tidying and see what happens.

Michael

On Tue, 30 May 2023, 3:57 am Greg D., <gregd2350 at gmail.com> wrote:

> The other cause might be a CAN bus conflict, especially if they're running
> something like the OBD2ECU task.  The CAN busses are plumbed out both of
> the OBMSv3 connectors, so bus conflicts are easy to create.
>
> Greg
>
>
> Michael Balzer wrote:
>
> 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
>>
>>
>>
>>
>
> _______________________________________________
> OvmsDev mailing list
> OvmsDev at lists.openvehicles.com
> http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvehicles.com/pipermail/ovmsdev/attachments/20230530/e55c5331/attachment.htm>