Crash on start-up - another possible fix

DavidW

[Posted to the Pocket GPS "TomTom Navigator 2" forum, and also to TomTom Support via their web page]

Hi there,

This won't be the answer to all the "Navigator worked fine last time I used it, but now crashes on start up", but it's certainly one scenario that can affect even the latest version.

I have heard it said, reasonably, that a crash on startup can be caused by corruption of the map folder. I checked that first, particularly as I've been having some trouble with my SD card (though not really with its use in my iPAQ), but I proved that wasn't the problem here. I copied the map folder back to the PC over my network and used Windiff between the copy I'd just made and a known good copy to verify the map folder was intact.

I discovered that this problem is caused by what is arguably a bug in the GPS driver.

I'm using Navigator 2.05 (UK) and GPS 2.05, which are the latest versions of both pieces of software.

I was using Navigator in bed last night to investigate some routes. As is usual in these cases, I didn't have my GPS card inserted (I had my wireless LAN card inserted, which is usual when I'm at home).

With Navigator 'crashed', I found by accident that the IR port was open. I happened to wave the Pocket PC in front of my infrared adapter whilst trying to debug this problem and Windows 2000 detected the presence of the Pocket PC.

I knew this was abnormal, as I have the option to discover incoming beams turned off so the Pocket PC should not have been detected. Starting the GPS driver from Start Menu, Programs caused the machine pretty much to slow to a halt just as starting Navigator had, so that implied that the problem was with the GPS driver being set to the wrong COM port. I was hoping to get the GPS tab opened to change the options, but couldn't make it there and had to soft-reset.

Somehow, when using the software with the GPS card not inserted, the GPS driver had configured itself onto COM3:, my iPAQ's IR port, as COM6: (what the TomTom GPS driver calls CF_CARD GENERIC) was not present as the GPS card was not inserted.

After a soft reset, a quick search of the registry found the relevant setting was at HKEY_LOCAL_MACHINE\SOFTWARE\TomTom\GPS Engine in the Option value. I changed that to COM1: and restarted the GPS driver, getting the expected error because COM1: on my iPAQ is claimed by the keyboard driver. However, I could then insert the GPS card and switch to the relevant tab to change the setting back to its usual CF_CARD GENERIC

Problem solved!

This may explain some of the cases where a total uninstall / reinstall of everything including the maps hasn't helped (of which there's at least one in the Pocket GPS forum). The duff setting may persist in the registry, no matter what is reinstalled.

David

DavidW

[Some further thoughts - the forum seemed to cut these off part way through - the post to TomTom contained both parts]

It seems that the GPS driver's handling of CompactFlash GPSes is not that clever anyway. I usually can't enter Demonstration mode unless the GPS card is inserted. Attempting to do so usually results in an "Unable to start demonstration (2)" error across the Navigator screen after selecting the demonstration option.

I would like to suggest to TomTom that three changes are made to the GPS driver to improve robustness and hopefully avoid this scenario in the future.

Firstly, I suggest that the GPS driver is improved so that accidental selection of the IR port can be got out of without recourse to a registry editor. I'm not sure there are any IR GPSes anyway. At the moment, the machine becomes so unresponsive that little can be done other than a soft reset, which leaves the problem to recur the next time the GPS driver is opened.

Secondly, whilst recognising that it is arguably a good idea to reflect accurately the ports available to select on the machine when the GPS driver is first configured, I suggest that once a GPS has been found on a CompactFlash port, that the GPS driver remembers that setting and simply resolves that the GPS is not available if the CompactFlash COM port is unavailable. That would avoid any risk of accidentally selecting a port that may cause problems. Obviously if an explicit new port selection is made, it is correct behaviour to only offer ports availabe at the time.

Thirdly, if the second suggested improvement doesn't resolve the problem with route demonstration, add a suitable fix to solve that problem as well.

David

DavidW

Well, I hope TomTom got that message - the thankyou.html page that you're redirected to after the form is submitted is a 404 - File not found!

I tried submit twice. Hopefully, if it isn't working, they'll read about it here anyway.

David

	PocketGPS
	Web