TomTom 2004 GPS Fix Time Issues

[Ball]

I have been having some really strange problems with TomTom Navigator 2004.

1) Starting TomTom 2004 it can take 5+ minutes for a GPS fix.
2) If I leave my PDA in EXACTLY the same locaiton and quit TomTom 2004 and startup Tom Tom's GPS utility "Tom Tom GPS.exe" I can connect and get a 3D fix on my CF-CARD GPS in <5 seconds.
3) I switch back to running TomTom 2004 and again it takes 5+ minutes for a fix.

So both TomTom Navigator 2004 and Tom Tom GPS.exe both use the exact same GPS engine ttgpseng.exe and yet one gets a virtually instantaneous 3D fix while Navigator takes ages. Obviously something must be wrong with TomTom Navigator 2004 and its interface to the GPS engine.

Anyone else noticed a similar issue with GPS fix times with TomTom Navigator 2004?

I am using a Holux 270CF GPS Compact Flash card and a Pocket PC 2002 (casio E200).

Thanks.

[lbendlin]

Actually they may not be using the same ttgpseng.exe . Make sure you have only one copy of the file on your Pocket PC, and make sure it's the one from TTN2004.

The longer time to fix most probably results from the way TTN2004 handles unknown receivers (non-serial/non-BT). It may force them into a factory reset, and then the receiver has to start all over. As you know, CF and Jacket GPS are officially not supported by TTN2004.

How did you set the receiver up - as "Other Bluetooth Receiver" ?
_________________
Lutz

Report Map Errors here:
TomTom/TeleAtlas NAVTEQ

[Ball]

Thanks for the quick response.

I've checked my pocket PC and I only have one ttgpseng.exe and it is located in my \Windows directory. I also re-installed TTN2004 to make sure it is the 2004 version of the GPS engine. My registry key \SOFTWARE\TomTom\GPS Engine also correctly points to the ttgpseng.exe in my windows directory.

In TomTom 2004 I have my GPS setup as something like "Cable GPS Other" and then under connection option I select "CF_CARD_GENERIC". Using the TomTom GPS.exe utility I choose NMEA 4800 as the model and CF_CARD_GENERIC as the connection option (choosing Holux270CF as the model also works well).

Your comment about TTN2004 possibly issuing a cold restart or factory restart may be the problem because when I use a GPS utility to cold reset my GPS it does take about the same amount of time to then get a 3D fix as when TTN2004 starts up.

Very annoying because I need to wait for a GPS fix before starting to drive or else it can take 15-20 minutes to get a GPS fix with TTN2004...so it does seem like it cold starts my GPS every time.

[lbendlin]

[Ball]

I think I just stumbled upon something here that makes me think that the problem is not that TTN2004 is performing a factory reset of my GPS. It doesn't make any sense at all but here's what I've found:

While waiting for my TTN2004 to take its 5+ minutes to get a GPS fix I went to check my contacts by pressing my contacts button...and low and behold the second my contacts program comes to the foreground of my PocketPC my GPS locks in. Switching back to TTN2004 I see that all the satelites are now in view and it is tracking my position. Now this seemed too strange to be true and perhaps coincidental and so I quit TTN2004 and restarted it. Again it started up showing no signals from any satelites. I wait about 30 seconds and still no satelite signals are registered. I press my contacts button. Contacts program comes to the foreground and sure enough I hear ttgpseng give a beep saying it has aquired a fix and my gps fix indicator starts flashing.

I've tried this numerous times now, waiting various amounts of time (from 10 seconds to about 2 minutes) before switching to another application and every time, the moment I bring ANY other application to the foreground in my pocket PC, my GPS finally establishes a fix with TTN2004. If I leave TTN2004 in the foreground during GPS initialization it will take anywhere from 5 to 10 minutes (sometimes even longer!) before aquiring a fix.


So while I don't quite understand what is causing this, atleast now I have a workaround. 1: Start TTN2004, 2: After GPS gets turned on I press my contacts button and wait ~20 seconds for my GPS fix, and then 3: Press another hotkey on my PPC that brings TTN2004 back to the foreground.

I was wondering, do you think this could be because I have an older/slower model PPC (Casio E200)? I was thinking that TTN2004 performs some extra-fast update rates of the GPS position on the screen (well at least a lot faster than I've seen in other GPS applications). I wonder if my problem is due to TTN2004 bogging down my PPC processor so that ttgpseng.exe does not have enough time to properlly initialize my GPS. With TTN2004 minimized (well in the background), maybe it is freeing up my processor enough to allow the GPS engine to get the GPS fix.

[lbendlin]

While it sounds a little far fetched it may have some merit. I noiced that TTN2004 (as well as TTN5) is very reluctant to yield control back to the operating system . Maybe you have noticed that pressing a hardware key does not show immediate results when TTN is running in the foreground. I even have seen cases where the key presses were ignored altogether.

So getting a fix is not the problem, but establishing the serial communication is.
_________________
Lutz

Report Map Errors here:
TomTom/TeleAtlas NAVTEQ

[lbendlin]

While it sounds a little far fetched it may have some merit. I noiced that TTN2004 (as well as TTN5) is very reluctant to yield control back to the operating system . Maybe you have noticed that pressing a hardware key does not show immediate results when TTN is running in the foreground. I even have seen cases where the key presses were ignored altogether.

So getting a fix is not the problem, but establishing the serial communication is.
_________________
Lutz

Report Map Errors here:
TomTom/TeleAtlas NAVTEQ

[Ball]

In the hopes that TomTom reads these forums I thought I'd post what else I've been able to find out about my problem.

Following the theory that my GPS Fix time might be related to TTN2004 loading down my PocketPC and preventing ttgpseng from initializing my GPS properlly I downloaded a utility that logs the messages that a Pocket PC application receives.

What I found was that while TTN2004 is in the foreground it is sending a message to ttgpseng about 4 times a second. When you bring another application to the foreground (and therefore put TTN2004 to the background), TTN2004 stops sending these messages to ttgpseng. I have noticed that ttgpseng acquires the fix in < 10 seconds when it is not being bombarded by these messages from TTN2004.

To follow up on this a bit further I did the same test with Tom Tom GPS.exe. Note from my previous post that Tom Tom GPS.exe consistently gets a near instant fix with my GPS. Here I noticed that Tom Tom GPS.exe also sends a message to ttgpseng periodically but at a much slower rate - about 1 message per second.

So from these tests it looks like these periodic messages may be what is preventing ttgpseng from getting a quick GPS fix on my Pocket PC. When these messages are absent (by putting TTN2004 to the background) or when these messages are sent at a slower rate (as in the case of Tom Tom GPS.exe) I get super fast fix times. When these messages are sent at fast rates (4 times per second), my GPS can take 5-15 minutes to acquire a fix. It seems like my problem would be solved if TTN2004 would not send these messages (or atleast send them slower) until after it sees a GPS fix.

Anyway, sorry if this is not relevant to this forum. I thought I would post it in case Tom Tom reads this. Who knows...maybe they can figure out what is going on and how to make sure this problem won't happen in the upcoming Navigator 5 release.

Cheers, and thanks for your responses.

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