TTN 5 GPS position racing ahead - fast & jumpy

[grahamwalker]

I've upgraded the OS on my XDA2. All of a sudden, my TTN 5 has become fast & jumpy. The GPS position on the map races ahead of itself by up to 400metres and then jumps back to where I really am on the road - and it does this cyclically every two or three seconds, which is really annoying.

Its not the GPS because it does the same using either my wired or bluetooth GPS receivers.

The new OS has a bigger pagepool, which I guess is like a "memory cache", so I suspect its just running too fast for the Tomtom software.

I don't want to downgrade my OS again, but Tomtom's driving me mad.

Has anyone else experienced the same problem or does anyone know how to slow down Tomtom's GPS map position plotting (via a registry hack or something....)?

All help gratefully received!

[Border_Collie]

For your pointer to show 400 metre ahead TT must have received info from the satellites to say you are in that position. The next info TT receives is telling you you are in another position. This would point to wrong NMEA information being received by TT.

Unistall and re-install TT.
_________________
Formerly known as Lost_Property
And NO that's NOT me in the Avatar.

[grahamwalker]

Done that several times. Hard reset my device and reinstalled only TTN5 to make sure it wasn't anything else.
Have tried it both with the "vanilla 5.21" EXE and also with the backlight fix version.
All do the same.

The TomTom software will only get a fix from the receiver every "x" seconds.
In between it must slowly advance the map (just like it continues to do when you lose a satellite signal).

I reckon that it gets a real plot every 2-3 secs (which is when it jumps back to the correct position) and its the bit of software that tris to move the map forward slowly in between that's running too fast and needs to be slowed down somehow.

[Border_Collie]

It's possible that when you updated, one of the required NMEA data $trings was changed or switched off.

Get THIS and check your NMEA settings.

Before Starting Winfast make sure you select your Port and baud rate.

DON'T mess with the SiRF settings.

The NMEA settings will look something like this.

GGA= 1 (is giving for instance inormation about the position, elevation and so on)
GLL= 0 (is giving the same, but less, inormation than GGA)
GVA= 5 (is giving the connection-signals of the different satelites)
GSA= 5 (the positions of the satelites)
RMC= 1 (recommended minimum data)
VTG = 1 (course over ground and ground speed)

If your settings are different, change them to the above and follow Go into Tools (below).

If they are as above then change both GLL and GVA to 1.

Go into Tools - Command - Re-set mode. Untick the two boxws and do a factory startup. Make sure you are outside under a clear sky and if you have an aerial attach that, it speeds things up a bit.
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Formerly known as Lost_Property
And NO that's NOT me in the Avatar.

[grahamwalker]

Great minds think alike.

That's just where I've been for the last 30 mins trying different settings with Leadtec Navigator - but all to no avail I'm afraid.

Off to try Plan C which is to cook a variant of my new OS ROM with smaller pagepool to see if that fixes the issue, even if it is at the detriment of overall PDA performance....

[mikealder]

Being an XDA device is it the O2 ROM you have installed or something else? - if its the O2 ROM have you installed it using corporate mode rather than default/ personel mode. The difference is corporate stops the install of the O2 Active interface which I know causes eratic behaviour on some XDA devices (one of mine nearly went out of the window at 70 MPH due this problem) - Mike

[grahamwalker]

Thanks for the thought Mike, but no, its not the O2 rom with O2 Active, so that's not the culprit either....

The O2 roms stopped at Windows Mobile 2003, so I've been using generic WM2005 ROMs for the Himalaya (XDA2) device since then.

It was moving to WM2005 that forced me to move from TTN3 to TTN5 in the first place...

The standard WM2005 build has only 4mb of pagepool (cache) memory and the OS ROM I've just loaded (from Buzzdev.net) increases this to 32mb.

My suspicion is that TomTom's now getting a load of info from cache rather than from the storage card (or main memory) and its just running much faster than the software developers tested it for soewhere within the application....

As suggested above, I've changed the GPS settings to send the satellite position info every second rather than every 5, but that hasn't helped either.....

[Border_Collie]

[Border_Collie]

I forgot to add, you can get Winfast CE from HERE
It shows as Version 1.1 but is actually 1.3 with the added save facility.
_________________
Formerly known as Lost_Property
And NO that's NOT me in the Avatar.

[grahamwalker]

Thanks for the help lost_property, but its not the GPS signal that's wrong - the software does exactly the same whether I used the wired GPS receiver or my bluetooth one.

So the problem must lye with the TTN5 application on the PDA itself.

I've tried all the various permutations of settings using the Leadtec config tool on my wired GPS, but that's only to see if changing the gps signal settings could compensate for the error in the application software....

[grahamwalker]

I think I've fixed it (just hope I'm not tempting fate....)....

When you install Tomtom, it must do some sort of speed calibration against the speed of the PDA - and it must store that info somewhere that isn't lost by completely replacing the ROM Operating System (which I assume can only be on the SD card...).

I tried changing the pagepool (cache) size of my XDA2 Rom 3.33 back from 32mb to the 5mb default by editing the ROM, but that didn't help, so I reverted back to Tofclock's 2.03 ROM (which used to work OK with TomTom 5) but that still skipped and jumped within the map display too.

So I was left with a dilemma that reinstalling a complete operating system (that used to work OK) and the reinstalling Tomtom from scratch still caused it to skip & jump, so there had to be something elsewhere (on the SD card or RAMdisk) that held some hidden config info....

Eventually I spotted and tried the icon within TomTom that does a "factory reset" - and this seems to have done the trick - even under my new 3.33 OS. I can only think that this recalibrates the Tomtom moving map process to the speed of the device and thereby adjusts for different speed roms.

If you change the rom and totally reinstall tomtom, it must still keep some old config info on the memory card that it uses again...

(at least that's my theory anyway....)

Anyway, I'm going to bed happy that it seems to work OK tonight, but then again, I thought it was working OK last night, but by this morning it was jumping again....

Watch this space!

[grahamwalker]

I have solved it - but it wasn't as simple as that and I'm not sure what the underlying issue is.

The "factory reset" fixed the jerky map because it deselected all my POIs.
As soon as I reselected the set of PocketGPS speed camera POIs so that they were displayed on the map, it became all jerky again.

It was fine under my previous ROM with all (24?) speed zones POIs enabled, but under the new ROM it can't cope.

If I just select a subset (gatsos, red light & temp) the map is OK again, so I'll have to live without map icons for specs and mobile cameras.....

For some reason, under the new ROM TTN5 is working differently and can't properly handle displaying all the speedzoned POIs.....

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