GPS Position lag in TT5.0

markyboy · Occasional Visitor Joined: Oct 01, 2005 Posts: 7

Hi,
I've just tested my bluetooth gps with TT5.0 on a short drive. even at <30mph the GPS position lagged my actual position by up to 300-400m.

If I stopped the car, it caught up after around 10-30sec.

I tried slowing the baud rate to 2400bps to see if it made a difference, but I didn't notice any change. If I use my wired GPS I do no get this problem.

I'm sure I read a previous post on this, but I couldn't find it.

Thanks

Mark
TT5.0 installed on an SD card on a Tosh E740 Pocketpc running Win2002.

lbendlin · Posted: Sun Oct 09, 2005 3:16 am Post subject:

which BT receiver?
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moonraker · Occasional Visitor Joined: Jun 05, 2005 Posts: 36

I see position lag as well, not as extreme but still some lag with an HP Ipaq Hw6515 with its own internal GPS unit. Some of my colleagues that have the 63xx series Ipaqs see lag too but they are generally using bluetooth GPS units often the Fortuna Clip On (Blue not Silver).

Some have put it down to the installation or not of the binaries onto the SD card, some say that TT5N is so processor hungry only the very latest procesors can keep up with it.

In the past there have been reports of SD card speed issues so it may be worth ensuring you have the fastest access SD card in there.

Sorry, more of a me too post than any help.
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lupos0_1 · Posted: Sun Oct 09, 2005 10:05 am Post subject:

Have you tried the update 5.1 from the tomtom website?

moonraker · Occasional Visitor Joined: Jun 05, 2005 Posts: 36

I have and I believe my colleagues have too.

lupos0_1 · Posted: Sun Oct 09, 2005 11:05 am Post subject:

if you are getting a good signal, I can't think of anytrhing else bar the processor not being able to keep up.

Have you tried disabling all the POI's??

markyboy · Occasional Visitor Joined: Oct 01, 2005 Posts: 7

The GPS I'm using is a Qstarz job. I check the reception with gpsinfo and it looks like it sees plenty of satellites (as much as I can tell).

So that leaves my processor speed or the SD card. As it was the cheapest SD card I could buy, maybe that is contributing?

I'll certainly try disabling the POIs.

I tried upgrading to TTN 5.1 but it just hung my PDA when I restarted it, so I have rolled back to the previous version.

Oh well back to wired GPS otherwise.

gazza_saab · Occasional Visitor Joined: Jul 28, 2005 Posts: 2

I've loaded TT5.1 on a new Axim x50v, connected to a GPSlim236, and noticed the same lag. I've now upped the processor speed to 624Mhz from the 'Auto' setting, but cannot try it out again until tomorrow. Does the bluetooth baud rate come into play here, like faster is better, or does it not really matter?

lbendlin · Posted: Mon Oct 10, 2005 9:45 pm Post subject:

stevei · Posted: Mon Oct 10, 2005 9:48 pm Post subject:

markyboy

Did you try hiding the POIs. I suspect that is what the problem is. It worked for me Laughing

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peterc10 · Posted: Mon Oct 10, 2005 10:01 pm Post subject:

I agree with previous post. I had similar problem on my Ipaq 6340 (not as bad). Hid the POIs and now spot on - and much smoother too. It still warns me of the POIs I have listed for warning - cameras.

markyboy · Occasional Visitor Joined: Oct 01, 2005 Posts: 7

I'll try hiding the POI's tomorrow, as I've got a bit of a road trip. I'll report back on Wednesday night (or Thurs if I'm late in.) I'll also try setting the GPS to 38k baud like Lutz suggests.

Regards

Mark

raptorheli2 · Occasional Visitor Joined: Aug 03, 2005 Posts: 33

i have all POI's off/deleted, 5.1, fast SD card, axim x50v and i still have the lag. it's not a lot but it's enough to be annoying and defeats the purpose of it imo.

i'm beggining to think the bt gps rx i have is not up to the job (navamn 4410) when it works perfectly well with ttn3.

how do i check the bluetooth baud rate to make sure it's at 34k ?

cheers

lupos0_1 · Posted: Fri Oct 14, 2005 1:10 pm Post subject:

Switch on tomtom, tap on the bottom right corner (satelite signal), tap on the satellite signal again and then tap configure. Scroll to the gps receiver you are using and then follow instructions.

Good luck

markyboy · Occasional Visitor Joined: Oct 01, 2005 Posts: 7

Hi all,

I tested the bluetooth device on my way down the M4. I turned off POIs, and configured the device for 38.6kbps.

Within maybe five to ten minutes it was lagging considerably. If I watched the screen update, I could see it plot a couple of points forward then jump one back. Presumably this was caused by TT decoding position reports out of sequence due to not enough processing power. Oh well.

I intend to use the device with my phone and TT mobile, but I'm waiting on a memory card before I can install. I'll update this thread with the performance of that system when I do.

Regards and thanks for your help,

Markyboy

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