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Posts: 26 | Thanked: 4 times | Joined on Dec 2005 @ Amsterdam
#31
Had a very frustrating experience again. Went for a 4-day visit to Berlin, and before going, I made sure the N810 had a proper GPS fix. When I got to Berlin it didn't get a fix, so I left it overnight at the hotel room window (19th floor) - but during the 4 day visit, it never got a fix, despite being with me , often in open places, in the day, and in the window every night.


Back here in Amsterdam it eventually got a fix again, but it is still very iffy. Whenever I start the map app (or maemo mapper), it can take hours for it to get a fix, even if it sees 10 satellites - it just doesn't lock to them.

Doesn't sound like a hardware problem to me - more likely software/firmware.
 
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Posts: 1,635 | Thanked: 1,816 times | Joined on Apr 2008 @ Manchester, England
#32
julf, this again sounds exactly like my problem.
I now make a habit of rebooting properly before relying on gps.

I left mine all afternoon like you with no fix, after a reboot and placing in same spot i t got one very quickly.
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Posts: 26 | Thanked: 4 times | Joined on Dec 2005 @ Amsterdam
#33
Tried a reboot (once again), and after 10 minutes 4 satellites are visible, but none in use - no fix
 
allnameswereout's Avatar
Posts: 3,397 | Thanked: 1,212 times | Joined on Jul 2008 @ Netherlands
#34
Originally Posted by Julf View Post
Tried a reboot (once again), and after 10 minutes 4 satellites are visible, but none in use - no fix
I had the same problem while i was in Amsterdam. I bought a dedicated BlueTooth GPS with Sirf III chipset. Works perfect, fast lock, always have a lock, and don't lose lock either. They're sold on eBay (UK & DE) for 10-30 EUR.

If it takes a long time till satelites are visible you should try AGPS.

Also, there are reports minigpsd improves the internal GPS.
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Posts: 26 | Thanked: 4 times | Joined on Dec 2005 @ Amsterdam
#35
Hi!

I have already been using AGPS, still doesn't seem to help. Will look into minigpsd, but you might be right, a separate bluetooth GPS receiver might be the answer - bit of a bummer, as I upgraded to a N810 especially to get the GPS capability.
 
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Posts: 3,397 | Thanked: 1,212 times | Joined on Jul 2008 @ Netherlands
#36
You're not the only person who is unhappy with the GPS of the N810, nor the only person who decided to buy the N810 for its GPS capability. What can I say? I share your pain. However, the N810 also has other (dis)advantages over the N800. If they're not worth it for you, you might want to sell the N810 and buy a different device instead (e.g. N800).

If you're using AGPS (and set it up correct) you should have satelites in view immediately. Not 10 minutes. However, for me, that still didn't solve the problem because I simply could not get a lock or if I had it it'd be so useless because it'd lose the lock. In the middle of Amsterdam (whole Amsterdam centre, Amsterdam Amstel).

Minigpsd isn't easy to set up IMO, but if you read the thread on ItT about it well you'll manage.
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Posts: 26 | Thanked: 4 times | Joined on Dec 2005 @ Amsterdam
#37
Exactly the same experience with AGPS - the N810 sees the satellites, but doesn't get a fix.

Will try Minigpsd.
 
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Posts: 1,310 | Thanked: 820 times | Joined on Mar 2006 @ Irving, TX
#38
Sometimes the A-GPS Beta does "lock up" so that the tablet will not get a fix. It has happened to me few times. I did fix it by going into A-GPS UI application and disable A-GPS. After that the tablet finds the satellites the old (slow) way, but does work after all. The other method (reboot) also helps.

I have had three different N810 tablets in my possession and all of them have been rather consistent with each others. All of them did get lock withing 2-5 minutes (without A-GPS) both in Texas and in Finland. With A-GPS the lock time is less than 1 minute. (Excluding cases with the A-GPS lockup issue above.)

So it could very well be that your N810 does have hardware defect (GPS antenna bad?) so that it doesn't get a fix. What I have noticed that the satellite signal strength needs to be over "30" (in MaemoMapper) to get a fix. If it is less, the tablet doesn't seem to get a lock, regardless how many satellites is visible. Have you checked the satellites signal strength if it is too weak? If it is then you should suspect HW defect.
 
Posts: 26 | Thanked: 4 times | Joined on Dec 2005 @ Amsterdam
#39
Hmm... I tend to get satellite signal strengths between 22 and 25, so it does indeed sound like something is wrong with the GPS receiver/antenna. Duh! I guess the N810 is out of warranty by now...
 
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Posts: 1,310 | Thanked: 820 times | Joined on Mar 2006 @ Irving, TX
#40
Originally Posted by Julf View Post
Hmm... I tend to get satellite signal strengths between 22 and 25, so it does indeed sound like something is wrong with the GPS receiver/antenna. Duh! I guess the N810 is out of warranty by now...
That's sounds about same signal strength for my tablet if I try to get a lock inside my house. Doesn't the N810 have 1 year warranty?

To clarify at least the strongest satellite should show consistently over "30" signal strength. The other satellites can be weaker. I believe the GPS chipset needs to receive some data stream from one satellite in order to calculate fix. If the signal strength is too weak it will never get a good set of data, and will not get a fix. Once there is a fix the GPS can keep lock with weaker satellite signal.

I think there is some WiKi page where this is explained in great detail...
 
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