TT3 GPS Tracking

dibble · Posted: Mon Dec 06, 2004 2:02 pm Post subject: TT3 GPS Tracking

Hi All!!

I am running TT3 on a Mio 168 with the speed cam DB with checkpoint 3.2.

When I sit still, TT3 locates me 100% but when I'm moving it tracks about 175 meters behind all the time. This means sometimes TT3 does not give me instructions in time. Also, when I get close to a speed cam it gives me a warning but only once I have driven past it! Laughing

I have compensated for that by increasing the warning time. It tracks my route fine though and locates me ok.

Anyone else find this? Is it a tweak or this how it is!!? Confused

Thanks

Dibble

lbendlin · Posted: Mon Dec 06, 2004 2:45 pm Post subject:

Are you by any chance running the reciever in SiRF mode? Or in Xtrac 1 mode?
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Lutz

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DavidW · Posted: Mon Dec 06, 2004 4:01 pm Post subject:

I don't think any of the Mio 168 built in GPSes have XTrac firmware - but I'm prepared to be surprised on that.

One possibility is a bad storage card - that has produced lags in TomTom software before now. Is the lag any better without CheckPOInt?

Another possibility is poor GPS reception - such as in a car with an athermic windscreen.

David

lbendlin · Posted: Mon Dec 06, 2004 4:26 pm Post subject:

I had a Mio 168 here for testing, and it told me it runs on Xtrac V2... There seem toi be different versions out in the field, and you really have to open the COM port to see what is in your particular device.
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DavidW · Posted: Mon Dec 06, 2004 5:41 pm Post subject:

Thanks Lutz - so it's clearly possible for these devices to come with XTrac firmware even if those on general sale are all non-XTrac.

David

Dave · Posted: Mon Dec 06, 2004 8:36 pm Post subject:

Any GPS chip running the SiRF IIe/LP chipset can come with the firmware loaded. Either pre-loaded at the factory, or loaded by someone who knows what they're doing (but most of the times this is at the factory). By loading XTrac 1 or 2 will disable WAAS. I've had a few firmware loaders entrusted to me which will allow you to re-flash the GPS chip providing you use the correct chipset and ROM available.

DavidW · Posted: Mon Dec 06, 2004 8:59 pm Post subject:

Indeed - though I wasn't any Mitac Mio 168s being sold with XTrac firmware loaded. Clearly there are XTrac Mios out there.

David

dibble · Posted: Tue Dec 07, 2004 12:19 am Post subject:

Hi Lutz/David

I have just checked my settings and I appear to be running in sirf 4800 mode, serial cable on SP2.

I had a quick look but don't appear to have anything on the system like "xtrak" I think you said.

With regards to the reception, I seem to have good sat signals all the time getting around 8 - 11 most of the time.

I did look to see if other sirf settings made any difference but didnt seem to get any sat signals at all.

I will run the system without checkpoint tomorrow to see if the distance is the same and advise.

Thanks for the help so far.......

Dibs

lbendlin · Posted: Tue Dec 07, 2004 2:22 am Post subject:

You need to change to NMEA mode to get rid of the delay.
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Lutz

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DavidW · Posted: Tue Dec 07, 2004 12:49 pm Post subject:

As Lutz says, switching to NMEA mode should get rid of the lag. You may get away simply by changing the settings to TomTom wired GPS, but if not, a program like Winfast Navigator will do the job.

David

dibble · Posted: Tue Dec 07, 2004 1:45 pm Post subject:

Hi Lutz/David

I have today changed the settings as you advised to NMEA mode. I have several settings in this area....I was using sirf 4800 with serial cable SP2.

Can I assume I should use NMEA 0183v2 4800? If this is the case, it seems to default to a COM port in the other setting, should I leave that or change it to serial cable SP2?

Sorry for all the questions guys but I'm new to this (you don't say!) and a little confused about it all! Laughing

Thanks for your time.

Dibs

DavidW · Posted: Tue Dec 07, 2004 2:19 pm Post subject:

Changing to NMEA 0183v2 4800 won't work - but changing to TomTom Wired GPS might (as it will hopefully send the necessary configuration command to the GPS hardware to flip it to NMEA mode).

You need to reset the port to SP2 if it changes to anything else.

David

ARH · Occasional Visitor Joined: Jul 14, 2004 Posts: 15

NMEA 0183v2 4800 on sp2 should work it does on mine.

dibble · Posted: Tue Dec 07, 2004 10:04 pm Post subject:

Hi All!

I have altered my settings to NMEA as advised and it works a treat! I am being tracked much more closely now and when I pass a junction or speed cam, I am actually next to it in the car. This is going to make the device much more usable now.

I still don't really know why this setting should be so different from the other - I mean radio signals are still going the same speed! I can only assume the routing is different or the device program is set up for one more than the other. Confused

My thanks to Lutz and David for their kind assistance - I was about to accept it as it was!!

Dibs :D

DavidW · Posted: Wed Dec 08, 2004 12:55 am Post subject:

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