how to read gps status page

[69gm]

so my tomtom worked fine when i left honolulu. packed it up with the intent of using it in reno. put so much faith in it that i didn't bother with any mapquest back-ups. i get to reno, turn it on...no signal...EVER. tried the whole week i was there. nuthin'.

get back to honolulu, and sure enough, no signal. i've been trying all the usual tricks (hard reset, soft reset, deleting and redoing quickgpsfix, etc.) and still no signal. can't figure it out.

but to add to my frustration is that i don't know how to "read" the gps status page. i get lots of gray bars, no gray bars, lots of gray dots, no gray dots...what does all that mean? i guess i'm trying to understand what tomtom is trying to do by looking at the status page and i'm encouraged when i see lots of bars...albeit gray ones. no signal lock though.

is there a primer on how to read that page just so i get a better understanding on what i'm looking at?

thanks in advance.

confused me...

 

[reggavegga]

if it has a sandisk card take it out and wait a couple of minutes then put it back in.i got another one off of ebay that worked but wouldnt get signal switched my sandisk cards then switched back and works great.

 

[69gm]

if it has a sandisk card take it out and wait a couple of minutes then put it back in.i got another one off of ebay that worked but wouldnt get signal switched my sandisk cards then switched back and works great.

hi!

thanks for the reply! my card is not a sandisk...it's an OCZ. i'll still try it though. couldn't hurt!

 

[mvl]

so my tomtom worked fine when i left honolulu. packed it up with the intent of using it in reno. put so much faith in it that i didn't bother with any mapquest back-ups. i get to reno, turn it on...no signal...EVER. tried the whole week i was there. nuthin'.

get back to honolulu, and sure enough, no signal. i've been trying all the usual tricks (hard reset, soft reset, deleting and redoing quickgpsfix, etc.) and still no signal. can't figure it out.

but to add to my frustration is that i don't know how to "read" the gps status page. i get lots of gray bars, no gray bars, lots of gray dots, no gray dots...what does all that mean? i guess i'm trying to understand what tomtom is trying to do by looking at the status page and i'm encouraged when i see lots of bars...albeit gray ones. no signal lock though.

is there a primer on how to read that page just so i get a better understanding on what i'm looking at?

thanks in advance.

confused me...

The bars on the bottom of the status page represent each satellite that the tomtom identifies. The height represents signal strength. The number on the bar represents which satellite number is identified.

The upper right shows where each numbered satellite is physically in relation to the tomtom.

All the satellites are in grey, when tomtom knows how far they are from the tomtom, but not exactly where the satellites are (GPS satellites are not geostationary). Every 5 minutes or so, each satellite sends out a broadcast on where it and all the other satellites are, and the broadcast is good for 2-3 hours. You need very good reception (usually 75% strength or more on one of the satellites) to get the location broadcast.

Once tomtom gets that broadcast, it draws the satellite in the upper right picture. I think requires 4 satellites minimum to triangulate its position. Once the position is triangulated, the color of the satellites used to ID the position change from grey to another color (the "good" color is different on each model / color scheme). The more satellites it ID's, the more reliable the location fix is.

QuickGPSfix is a file that lists the locations of the satellite for the next week, and speeds up this process.

If you change locations drastically (eg honolulu to vegas), tomtom may have memory of a satellite location in the completely wrong place. When it gets broadcast location info from some satellites that are completely contradictory to others in its memory, it refuses to triangulate a position. You have to wait until the mislocated satellite that it remembers rebroadcasts its location. Usually a hard reset or a SD card removal causes tomtom to forget this memory, so it starts satellite acquisition fresh.

I've found the best way to get signal is to be outdoors with a clear view of the sky, which should result in many of the bars above 75%. Then wait (preferably not moving) for about 5-10 minutes. If you're arriving at an airport, turn it on and leave it on after the plane lands, so it can acquire signal while walking around to baggage claim, etc. I may just be superstitious, but it also seems to acquire signal faster if the satellite info screen is being displayed.

 

[Ricochet]

Awesome explanation!

 

[gatorguy]

MVL, just a minor correction to what you've written (which was quite good BTW). Each of the sats are actually broadcasting on 30 second cycles. If your pnd "finds" a particular sat mid-broadcast, then it will take another 30 second cycle after the current one for your device to receive the full positioning data.

 

[69gm]

mvl,

thanks a bunch! that was a great explanation.

another question though...what does it mean when the bars are at full capacity, yet still gray? i guess i was a little confused since i did assume that it meant signal strength so i was confused at "full strength", yet gray.

i have left my tomtom on for an hour and nothing.

my next step will be to copy the contents of my sd card via explorer (as dhn always recommends) and reformat the sd card and copy everything back. it's a long shot but i'm getting desperate. btw, i have tried to turn on the tomtom without the sd card and still no signal.

worst case scenario...did my poor tomtom die?

 

[canderson]

mvl,

thanks a bunch! that was a great explanation.

another question though...what does it mean when the bars are at full capacity, yet still gray? i guess i was a little confused since i did assume that it meant signal strength so i was confused at "full strength", yet gray.

i have left my tomtom on for an hour and nothing.

my next step will be to copy the contents of my sd card via explorer (as dhn always recommends) and reformat the sd card and copy everything back. it's a long shot but i'm getting desperate. btw, i have tried to turn on the tomtom without the sd card and still no signal.

worst case scenario...did my poor tomtom die?

It is possible you got a bad quickgpsfix. Either connected to your PC or using DUN on a cell phone, pull down a recent one. That may help a lot.

Tall gray bars show good signal, but no usable data.

 

[69gm]

It is possible you got a bad quickgpsfix. Either connected to your PC or using DUN on a cell phone, pull down a recent one. That may help a lot.

Tall gray bars show good signal, but no usable data.

appreciate the clarification. thanks!

i've tried numerous times to redo the quickgpsfix. is there a good way to do it? i've been mostly copying and older one to my sd card and letting TTH notice it was old and offering me a new one. i've done this a few time already...any other suggestions?

still desperate!

 

[dhn]

Use Explorer to look at the contents of your unit. You should have a folder called ephem. Delete the contents but not the folder.

Also, in this folder:

C:\Documents and Settings\yourname\My Documents\TomTom\HOME\Downloads\complete\ephemeris

delete the contents (all the folders you see) but not the ephemeris folder itself.

Now, connect to Home again. You should get a new gspquickfix file.

 

[69gm]

Use Explorer to look at the contents of your unit. You should have a folder called ephem. Delete the contents but not the folder.

Also, in this folder:

C:\Documents and Settings\yourname\My Documents\TomTom\HOME\Downloads\complete\ephemeris

delete the contents (all the folders you see) but not the ephemeris folder itself.

Now, connect to Home again. You should get a new gspquickfix file.

tried these steps but TTH didn't give me any new quickgpsfix.

 

[mvl]

Try:

1) deleting the ephem contents on the tomtom
2) then pin reset (if your device has one), or hold the power for the hard reset if it doesn't

Don't plug it in to get a new quickgpsfix yet.

Then start up the tomtom and wait outside. Without a quickgpsfix and with prior GPS location memory wiped out by pin reset, it should get a fix in 5-10 minutes to get a new signal.

 

[Krellan]

Interesting. I've never moved a GPS that much distance. Leaving it on for an hour should have been plenty of time to pick up the satellites, though. How many of the gray bars are at their tallest position? Leave the TomTom somewhere where it can get a great signal, preferably outside, and keep it charged, for as long as possible. Hopefully you can get a GPS fix and get your location back again.

I didn't know about that epheremis file. Definitely delete it. Does the TomTom try to keep a memory of your old location in any other files? Unfortunately, I don't know. It does sound like the TomTom has been fooled, in that its attempt to give you a faster GPS lock by remembering your previous location has backfired, since you moved so far away, and now it can't lock on at all now.

NGS - PRECISE GPS ORBITS COMPUTED AT THE NATIONAL GEODETIC SURVEY

Maybe buy a Garmin while you're on the mainland, then when you go back to Hawaii, see which GPS locks back onto your Hawaii location first?

 

[69gm]

okay i've waited a couple of days to see how things would go.

i've had inconsistent performance so i waited. even today wasn't perfect...but better.

here are the steps i took to at least get things going again (better than no signal at all...)

followed mvl's most recent advice by letting TT find satellites with NO quickgpsfix data. eventually found some, albeit only like 4 at most. used device like that for a day. then decided to try to get quickgpsfix data again. after i did that i got all bars! yay! but the cautious side of me decided to wait another day.

sure enough i got slow or no gps signals. argh!!! but then decided to give it one last try and noticed that there was a new quickgpsfix again. got that and full bars again. *whew*. yesterday was good.

today i started up tomtom and again got nothing!!! lots of full strength gray bars but no "real" signal. after i got to work i stood outside, just for the heck of it for a few minutes. then i got signal again!

i just attached my TT to TTH and noticed yet another quickgpsfix so i installed it. haven't gone outside yet to see if it's better.

the moral of the story? well at least my unit works...somewhat. better than before when i was getting absolutely nothing. but still waaaay slower at getting a gps fix than before.

i hope this helps someone else. i think my first advice is to follow dhn & mvl's advice and erase all quickgpsfix data on your unit and on your computer. then let the unit find satellites on it's own. once you can, try quickgpsfix again to see if your unit gets better.

i hope to see better days on my TT.

 

[mvl]

Hmm... I think tomtom only uses quickgpsfix when it's own memory has expired for a few hours.

So it seems like quickgpsfix continues to cause errors for you, that the satellite self identification eventually corrects.

First suggestion:

Try the clear flash tool from here (run it 3 times in a row):
http://www.tomtom.com/6178


Second suggestion if the first doesn't work:

In all your prior attempts at problem resolution, did you ever try unauthorized navcore's such as 8.320? There are different GPS chips in different models, and the quickgpsfixes for each are incompatible. Maybe you should "start fresh' from a software perspective.

1) Use windows explorer and copy the entire memory card contents to a backup on your computer
2) format the SD card (fat32)
3) use tomtom home to download/install the latest application
4) use tomtom hmoe to download your voice(s)
5) use tomtom home to download your map (if HOME has it available), or if it doesn't copy the map folder ("North America" or "USA and Canada") from your backup to the tomtom.
6) try downloading quickgpsfix again to see if things work

You'll lose all favorites, etc. If anything goes wrong, just copy your backup onto your memory card and you'll get back your old settings.

 

[69gm]

Hmm... I think tomtom only uses quickgpsfix when it's own memory has expired for a few hours.

So it seems like quickgpsfix continues to cause errors for you, that the satellite self identification eventually corrects.

First suggestion:

Try the clear flash tool from here (run it 3 times in a row):
TomTom, portable GPS car navigation systems - Support home - Select your product


Second suggestion if the first doesn't work:

In all your prior attempts at problem resolution, did you ever try unauthorized navcore's such as 8.320? There are different GPS chips in different models, and the quickgpsfixes for each are incompatible. Maybe you should "start fresh' from a software perspective.

1) Use windows explorer and copy the entire memory card contents to a backup on your computer
2) format the SD card (fat32)
3) use tomtom home to download/install the latest application
4) use tomtom hmoe to download your voice(s)
5) use tomtom home to download your map (if HOME has it available), or if it doesn't copy the map folder ("North America" or "USA and Canada") from your backup to the tomtom.
6) try downloading quickgpsfix again to see if things work

You'll lose all favorites, etc. If anything goes wrong, just copy your backup onto your memory card and you'll get back your old settings.

hi mvl!

thanks for continuing your suggestions.

wow, i never clearflashed 3 times in a row! something to keep in mind.

no i have never tried 8.320. i am running whatever TTH has put on (currently 7.903?) do i just download and copy to TT? or how else. and where to get?

as far as your second set of suggestions, i've sort of done that already but didn't seem to help...at least that was my experience.

just a quick update: so far so good! it seems to be working as far as today. i will keep at it for a few days and see...

still don't know what happened in reno though. i've taken my TT with me all over and it's always eventually gotten signal. just not this time. i guess it got more confused than i anticipated.

question: is there some chance hardware is failing? how rugged are these units? maybe unit got bumped around too much? it was in my luggage...

 

[mvl]

If you've always kept to HOME offered updates, then the navcore version isn't the problem. So I wouldn't bother with the full system wipeout I proposed.

Yes, running clearflash up to 3 times is better than just running it once.

I can't speak to the hardware much - both my ONE and my GO were never dropped nor checked in as baggage (I used to travel for a living, airport staff often steal things from checked bags). My ONE LE is really old (bought used in 2007). Both are still running great.

Best of luck with it.

 

[69gm]

just a quick (and probably last) update.

my TT seems to be working fine again. still not sure what the hiccup was and not exactly sure what fixed it since i tried so many different things...although i'm sure mvl and dhn's suggestions helped.

anyway if anyone else has problems read through this thread and try all the different things suggested. at least one...or a combination...worked for me!

thanks all. this forum is the BEST!!!

 

[PowerliftingBBer]

In everyone opinion whats the best barometer setting and why....ex-deg,min,or seconds...? I noticed the degrees setting gives me the most satellites, I got up to 10 sats earlier today, TMK it has to do with the fact deg is more general of an area then min and sec, someone correct me if im wrong.

 

[canderson]

The units that you choose will have no effect on the number of satellites that you pick up. It's strictly a matter of convenience IF you have use for latitude/longitude information. Many people prefer decimal degrees (e.g., N39.18974?) but for my purposes (geocaching) I enter and read coordinates in degrees and decimal minutes (e.g., N39?20.103') since that is the notation we use.