Issues with the BT-Q818XT

I've been using TrackAddict / RaceRender for a while now, but I've been using my phone's internal GPS. However, I am getting to the point where I want more accurate positioning data to compare autocross runs. I bought a Qstarz BT-Q818XT and, paired it with my phone, and configured TrackAddict to use it. However, the resulting maps are completely insane.

Attachment 91493

Now, I just took this thing out of the box and paired it. Is there something more I need to do, either with the device or within TrackAddict, to make it work properly? I haven't connected the module to my PC and set up the "A-GPS" functionality yet, but am probably going to do so just to see if it helps.

I know it's a popular module so I figured I'd ask here first.

I just bought one too, and the first day wasn't very successful:

Attachment 91538

I seems to not line up with the track?

Then a bit later on it went nuts:

Attachment 91539

I also just took it out of the box and paired it, without doing anything else.

This was the first thread I found when I searched, and since it is so recent I thought I would just tag along.

Heh, at least yours isn't showing your car reaching orbital velocity, but clearly its just as useless for trying to get precise data.

Near as I can tell so far, it's an issue with TrackAddict. I used to use another lap timer app (not naming names because I like TrackAddict better, but it's the other popular and inexpensive one). I fired it up, set it up to use the Qstarz module, and it worked perfectly fine.

My Qstarz is a few years old, but at that time I just paired it out of the box and its performed perfectly.

I've been digging into this more. So far, I still am unable to reproduce this issue in another track app. Meanwhile, I cannot get a "clean" session out of TrackAddict. I exported the raw data to look at the GPS coordinates TrackAddict reports and I am seeing massive shifts in longitude (-96.0291547 to 15.1833333) but latitude stays reasonable.

I *may* have fixed it. I've now gotten three successful tests after re-configuring the module, whereas before I didn't have a single success.

I plugged the module into my laptop, turned it on to the first position (labeled as 1 Hz), and ran the utility. At someone else's suggestion (and since the data seems worthless?) I turned off GSV. This significantly reduced the bandwidth needed by the device and seems to have made a huge impact on the reliability of it. I also set the 1 Hz switch position to run at 5 Hz instead, which still leverages DGPS and (in theory) provides for more accurate data.

More testing needed, but this sure seems really promising.

OK, I turned GSV to 0 as well.

I set the 1Hz switch to use 5Hz, but will try and stick to 10Hz first, and only use the 5Hz if it is still fubared.

the bandwidth dropped from 43% to 20% at 10Hz with GSV at 0, so that is promising, and the output in the data dump screen was a lot simpler.

Will let people know if it helped when I get a chance to test it.

Any Luck with this, I have turned of GSV, and running at 5 and 10 hz, today it said I drove to Antarctica and back, it said my morning commute was 352,000km long and took 7 minutes, the 7 minutes thing is the only thing it got right.

I should have an update on Friday, but by the sound of your experience I won't hold my breath.

Quote:

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Originally Posted by paulie

I should have an update on Friday, but by the sound of your experience I won't hold my breath.

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It's broken, it's old hardware and not really supported by modern android phones

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OK I have run 2 meets with GSV 0 and it seems to be working fine at 10Hz.
Accuracy seems good now, and lap times seems OK.

I didn't realise it was old hardware, I just bought what was on the recommended list for android.

Have you guys tried a mock gps provider app like bluetooth gps? as long as I remember to turn mine on it seems to map just fine. Normally when my gps fails it seems to be due to the phone trying to use internal gps at 1hz vs 5-10hz from the 818xt
https://photos.app.goo.gl/tzimg3uQwqtfj22w5 https://photos.app.goo.gl/tzimg3uQwqtfj22w5

I don't use my primary phone for trackaddict, instead I use an older LG G5 with built-in wide angle lens, works good