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Posts: 9 | Thanked: 8 times | Joined on Aug 2008
#1
Hi All,

I just got an N9 a couple of weeks ago and I'm getting concerned that it may have a defective GPS, and I just wanted to find out how well/poor the GPS behaves for others before I pursue getting a replacement (It least I'm in Australia so I didn't have to resort to a grey import).

I believe that aGPS is working (kinda...), but I'm concerned that it is ONLY using aGPS, and a full GPS lock is never achieved.

These are my symptoms:

Maps / Drive gets my approximate location fairly quickly, provided I am in certain locations (home, work, uni - my guess is that the Nokia supl server has learnt the location of the wireless networks in those locations).

When I'm anywhere else it is terrible, taking ages to get an approximate "lock", then often places me several streets to several suburbs away from where I actually am, and does not update while I move.

- Maps shows a green dot of where it thinks I am, and the dot rarely moves once it appears.
- Drive shows where it thinks I am (and also rarely moves) and the message "Looking for GPS" never disappears.
- GPSMeefo never gets off "searching for signal" and all satellites are displayed with 0% signal for as long as I've watched it.
- GPSSpeed shows the same lat/long as maps/drive, but always reports 0/9 satellites and an accuracy varying of between 40 and 100 meters (in reality the accuracy is often much worse than that).

Yesterday I started Drive before leaving work. Fairly quickly it put me several streets away from the (outdoors) carpark where I started, then moved around randomly (and inaccurately) while I was driving. When I got to the uni it started to alternate between the uni and somewhere near where I had started (now several suburbs away and on the wrong side of the lake), then incorrectly settled on my work location (!?!) and stayed there until I was almost home (now around 12KM as the crow flies from the location it was showing), when it finally updated as I pulled into my driveway it put me half a suburb away from my actual location (usually it finds my approximately correct location as soon as I get home, likely from the wireless network being broadcast at that location, so being half a suburb out at this point was unusual).

I've changed it to use the Google supl server and will repeat that experiment this evening - my guess is that the Google server may do a better job of finding my approximate location throughout the journey, but without actually getting a proper GPS lock I still doubt it will work any well.



I'm thinking about reflashing PR1.1 just to rule out anything I've installed or tweaked as causing issues (also, the OTA update to PR1.1 didn't seem to be go quite as smoothly as I would have expected and I have wondered if there is something missing, though other than the GPS everything appears to work).


Compared to my N900 and $130 Android tablet, both of which gets an aGPS lock in seconds, and a full GPS lock shortly thereafter, the behaviour of the N9 makes it completely useless for navigation, and even pretty unreliable to use the maps if I didn't already know where I was.

Cheers,
-Ian

Last edited by DarkStarSword; 2012-01-31 at 07:15.
 

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Posts: 49 | Thanked: 93 times | Joined on Jan 2012 @ Finland
#2
Hi Ian,

I have had similar GPS issues with my N9 as well! Your post is the first one I have managed to found about the same problem.

Usually the phone is not getting any real (A)GPS fix, no matter what. Instead it will only get some rough position with WLAN/Cellular network. This can easily be seen with GPSMeeFo application that doesn't report any satellites found, or Drive application that keeps saying "Looking for GPS signal" forever.

This is definitely some issue with my (and your!) device only, as I have tested so many times getting GPS position with multiple N9 devices on a same place at the same time. Every other N9 devices get GPS fix really fast, but mine keeps always saying that no satellites found.

I have found that sometimes rebooting my device helps for a while (and sometimes not). Furthermore, I did find out that restarting "nped" process (Nokia Positioning Engine Daemon) may help too, but next time while needing GPS, it's probably jammed again. Here is how to restart nped from terminal:

devel-su
/sbin/stop xsession/nped
/sbin/start xsession/nped

Have you checked your syslog (cat /var/log/syslog) after failing attempts to get GPS working properly? Any obvious errors there? For me there is sometimes nothing suspicious, but sometimes there is a flood of the following error messages (tens or even hundreds!!):

nped[1537]: i2c_write: Remote I/O error

I have tried to clear and re-flash my device, but nothing helps. The given I/O errors of I2C bus suggest to me that there could actually be some hardware failure on my N9 causing the problems. Somewhat faulty bus conductors on the mainboard or bad soldering of the GPS chip perhaps could cause this?

I have struggled with this GPS problem since the beginning (N9 launch), so I think it's getting time to take my N9 to service and demand the mainboard to be changed or a whole device.

-Kalle
 

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Posts: 177 | Thanked: 199 times | Joined on Nov 2007 @ Concepcion, Chile
#3
disable the "battery saver mode" and reboot with the usb/charger unpluged
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User:rlinfati
 
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#4
Originally Posted by DarkStarSword View Post
I've changed it to use the Google supl server and will repeat that experiment this evening - my guess is that the Google server may do a better job of finding my approximate location throughout the journey, but without actually getting a proper GPS lock I still doubt it will work any well.
I only quickly skimmed your post, but it sounds like your GPS issue is the same as someone in another forum.
I suggested the Google SUPL server tweak, and they've since confirmed that it has solved their issue.
 
Posts: 188 | Thanked: 90 times | Joined on Sep 2006
#5
Even without data / a-gps, any gps outdoors with not too obstructed view of the sky should get a fix in a few minutes - typically less than 5, theoretically, up to above 20 (fringe case, unlikely).

But if GPSMeeFo shows no sats, things are amiss for sure; well, at least if it's not an app bug. You could also try Track@Way free from the store, it also has some good GPS sat info screens.
 
Posts: 9 | Thanked: 8 times | Joined on Aug 2008
#6
Thanks for the replies everyone

Kallela: A lot of useful info, thanks - I'll keep an eye on the syslog and see if any i2c errors show up, and will try your suggestion of restarting nped. Very interested to hear that most N9 gets a GPS fix really fast, that was pretty much the confirmation I was looking for to work out if the problem was specific to me or a general problem with N9s.

rlinfati: I've got that set to automatic, but the battery was never low enough for it to kick in. I'll try fully disabling it and rebooting just in case.

jalyst: I've now tried using the Google supl server, but unfortunately it didn't help. In the repeat test as my first post it only put me at the approximately correct position four times in the journey - when I started, when I stopped at the uni, several minutes after arriving home, and very briefly at one point while I was driving down a highway. For the remaining 90% of the trip, it put me in a Suburb that I never even went close to (and kept reverting to that suburb even after finding my correct location at the uni). So, at the worst point in the trip it thought I was roughly 11KM away from my actual location as the crow flies.

aRTee: So far I haven't seen it getting a lock outdoors... I've tried for around 10 minutes so far. I'll try walking up a hill near my place on the weekend (if the weather is clear) and see if I can get anything in 20 minutes.

Thanks everyone,
-Ian
 
Posts: 104 | Thanked: 58 times | Joined on Dec 2011
#7
I recently noted something very similar. I'm often abroad and thus purely relaying on GPS without any "A". It takes my N9 sometimes really long for an initial fix...at least I thought so because Nokia Maps was still indicating my last position with an orange dot.

After reading this thread I finally tried GPS MeeFo and here I noticed that my GPS sometimes already had a position quite fast, but the parallely opend Nokia Maps was showing nothing but its orange location indicator forever.

For me it seems that Nokia Maps is pending or stops updating the position after a while. The result: An already found location isn't displayed until I restart Nokia Maps.
 
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Posts: 590 | Thanked: 475 times | Joined on Oct 2010 @ New York City
#8
Quite big tweaks are coming in Maps and Drive in PR1.2, I know that doesn't help you now, but it might help when it does. Sorry I don't use Drive (as I spent my $10K on an N9 ) but when I use Maps it works ok. Haven't noticed anything crazy with yet.

Good luck with it all.
 
Posts: 104 | Thanked: 58 times | Joined on Dec 2011
#9
Originally Posted by AndyNokia232 View Post
Quite big tweaks are coming in Maps and Drive in PR1.2, I know that doesn't help you now, but it might help when it does. Sorry I don't use Drive (as I spent my $10K on an N9 ) but when I use Maps it works ok. Haven't noticed anything crazy with yet.

Good luck with it all.
I'll wait for 1.2 and if this occurs still I will file a bug. Beside Nokia Maps loading really slowly and this strange behavior with initial GPS fixes everything is fine with my N9 & GPS so far!
 
Posts: 49 | Thanked: 93 times | Joined on Jan 2012 @ Finland
#10
DarkStarSword, so have you seen those I2C I/O errors in syslog?

I heard that it's normal to get one every time the GPS chip is powered on, but getting a flood of those, like I do, is something that should not happen.
 
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