GPS Fix - Dummies GuideTips


  1. ironass

    ironass Well-Known Member

    One of the features of the Samsung Galaxy S4, GT-i9505, quad core phone that I use a lot is GPS and Google Maps. Both for work and play. In fact, I've been using phone based GPS since my Nokia N80 days, some 7 years ago.

    However, the GPS and Google Maps on my Galaxy S4 in the UK knocks spots off of anything I've tried before, including my previous phone, the Galaxy S2.

    The S4 can pick up around 25 satellites very quickly and offers me a fix of within 3m, (9.84ft), in around 10 sec's or so on a clear day, outdoors. This compares to the Galaxy S2 which would pick up about 12 satellites and take slightly longer for a fix.

    In fact, so good is the S4 with GPS that I have abandoned using dedicated GPS equipment.

    In my own home the GPS can even detect the part of the house I am in with a slightly longer fix time.

    For anyone who is experiencing GPS location and/or fix time problems, there are a couple of things that you can do which may help... although it will not fix a broken/damaged GPS antenna or improve your GPS if your government offers a degraded or non existent service.

    1. On your phone go to Settings > More > Location services and ensure that Access to my location is set to ON and that Use GPS satellites and Wi-Fi & mobile network are both checked. In Google Maps, go to Menu > Settings > Google location settings and ensure that Access location is checked.

    2. Download GPS Status & Toolbox, free from the Play Store. There is a paid version but the free one will suffice.

    3. In GPS Status & Toolbox, go to Menu > Settings > GPS & Sensors > Auto-download AGPS data and choose how often you wish AGPS to be updated. I use once a day. You may decide more or less. Also Sensor filtering. I have mine set to weak but you can experiment. A stronger filter increases the GPS fix time a bit.

    4. Other settings you can choose to suit yourself and your location, such as meters/feet, miles/kilometers, etc: Unrooted users - go to #6

    5. For rooted users only. (Not necessary) Download FasterGPS, free from the Play Store and select your location. This now tells your GPS to use a local location service which can speed up your fix time. See Hawker's post, #6, below for more information.

    6. Now take your phone outside, away from buildings if possible and with a clear view of the sky. Open GPS Status & Tools > Menu > Tools and select both Compass calibration and Calibrate pitch and roll and follow the instructions for calibration.

    7. Now, still outdoors, put your phone into Flight Mode so that the phone is only using its internal GPS for a fix and go to Menu > Tools Manage A-GPS state > Reset and then leave it for around 20 minutes on a flat surface.

    8. After around 20 minutes, very carefully, turn Flight Mode off and in Menu > Tools > Manage A-GPS state > Download

    9. Now either, rotate the phone a couple of times through its three axis or do some figures of 8 with the phone.

    10. Go to Google Maps in Satellite mode and see how quickly you get an accurate fix.

    Because I am a heavy GPS user, I tend to do this once every month or two but for most peoples uses, once every three or four months should suffice, if that.

    Below is a screenshot of Google Maps in Satellite mode showing a local Ordanance Survey, "Trig Point". To show the plinth the trig point was on, I had to move slightly sideways as the blue location dot was covering it completely. This was with no Wi-Fi and on EDGE.

    [​IMG]


    This is a screenshot, taken at the same time, of GPS Status & Toolbox's, (Pro), readout showing a lock on 25 out of 26 satellites and a margin of error of around 3m/10ft, in fact it was so spot on I had to move to show the white plinth.

    [​IMG]

    Since all the apps I have mentioned are free, you have nothing to lose by trying it. Hope it helps!

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    jski, Hawker, edglar and 7 others like this.
  2. kenfb1

    kenfb1 Well-Known Member

    Hi,
    Took your suggestions and followed your instructions.
    Can't verify if it's better or not but I guess it can't
    hurt either. Thanks for your time to post this,
    Ken
  3. Harry2

    Harry2 Well-Known Member

    Thanks for your GPS tip :)

    As far as I know the S4 uses GPS and GLONASS for calculation the position.
    This could be the reason that the S4 sees twice as many satellites as the S2.

    Harry
  4. speedlever

    speedlever Well-Known Member

    I also have the GPS app mentioned above. I have not done the calibration routines, but my indicated error also shows 10ft. And that's inside after enabling the app and taking just seconds to lock in and max the accuracy.

    I find the GPS receiver on the GS4 to be incredibly sensitive... at least as compared to others I've had in the past.

    [​IMG]
  5. Shocky

    Shocky Well-Known Member

    GPS has been good since the Galaxy S2 but it's GLONASS that really made the difference.

    GLONASS was added in the Galaxy S3.
  6. Hawker

    Hawker Well-Known Member

    I too have been finding my GT-9505 (UK) very good with regards to GPS, both indoors and out.

    On my S2, I would be lucky (and I mean LUCKY) to get a solid fix on between 6 and 9 satellites. Indoors, I would hardly ever get a fix at all.

    On the S4, I regularly get a good fix on anything up to 20+ satellites in 5-10 seconds.

    One addition to ironass' great post here however, is instead of fasterfix, I use Faster GPS. This, like fasterfix, allows you to specify your NTP server, but it also gives you the ability to edit your gps.conf in any way you see fit (easier than manual edits).
    For example, in advanced settings, there is an ENABLE_WIPER option, that is defaulted to 0. Set this to 1 to enable wifi positioning
    Also, set DEFAULT_AGPS_ENABLE=TRUE (not set by default)

    both can help speeding up your fix even further.
    ironass likes this.
  7. ironass

    ironass Well-Known Member

    Cheers Hawker!

    Have revised post #1 to include this app as it offers greater configuration and speed for rooted users. :thumb:
  8. joesixpack

    joesixpack Well-Known Member

    Those were some good tips. Thanks for the post! My S4 works good, but the wife's S3 has been spotty at times. I'll try some of these out the next time she has problems.
  9. hanna211

    hanna211 Member

    i opened up gps.conf and seen the line

    NTP_SERVER=1.pool.ntp.org
    NTP_SERVER=0.europe.pool.ntp.org
    NTP_SERVER=1.asia.pool.ntp.org
    NTP_SERVER=2.north-america.pool.ntp.org

    can i add many as i can ????? example

    NTP_SERVER=0.europe.pool.ntp.org
    NTP_SERVER=1.europe.pool.ntp.org
    NTP_SERVER=2.europe.pool.ntp.org
    NTP_SERVER=3.europe.pool.ntp.org
    NTP_SERVER=4.uk.pool.ntp.org
    NTP_SERVER=5.uk.pool.ntp.org
    NTP_SERVER=6.uk.pool.ntp.org
    NTP_SERVER=7.uk.pool.ntp.org
    NTP_SERVER=8.at.pool.ntp.org
    NTP_SERVER=9.at.pool.ntp.org
    NTP_SERVER=10.at.pool.ntp.org
    NTP_SERVER=11.at.pool.ntp.org
    NTP_SERVER=12.ch.pool.ntp.org
    NTP_SERVER=13.ch.pool.ntp.org
    NTP_SERVER=14.ch.pool.ntp.org
    NTP_SERVER=15.ch.pool.ntp.org
    NTP_SERVER=16.de.pool.ntp.org
    NTP_SERVER=17.de.pool.ntp.org
    NTP_SERVER=18.de.pool.ntp.org
    NTP_SERVER=19.de.pool.ntp.org
    NTP_SERVER=20.dk.pool.ntp.org
    NTP_SERVER=21.dk.pool.ntp.org
    NTP_SERVER=22.dk.pool.ntp.org
    NTP_SERVER=23.dk.pool.ntp.org
    NTP_SERVER=24.es.pool.ntp.org
    NTP_SERVER=25.es.pool.ntp.org
    NTP_SERVER=26.es.pool.ntp.org
    NTP_SERVER=27.es.pool.ntp.org
    NTP_SERVER=28.fr.pool.ntp.org
    NTP_SERVER=29.fr.pool.ntp.org
    NTP_SERVER=30.fr.pool.ntp.org
    NTP_SERVER=31.fr.pool.ntp.org
    NTP_SERVER=32.it.pool.ntp.org
    NTP_SERVER=33.it.pool.ntp.org
    NTP_SERVER=34.it.pool.ntp.org
    NTP_SERVER=35.it.pool.ntp.org


    off course different coutries etc
  10. ironass

    ironass Well-Known Member

    That is to receive GPS timing information for positioning. You only need to select the one closest to you to speed up the process.

    E.g. United Kingdom = either...
    NTP_SERVER=5.uk.pool.ntp.org
    NTP_SERVER=6.uk.pool.ntp.org
    NTP_SERVER=7.uk.pool.ntp.org

    See item #5 in post #1 and also. post #6.
  11. koutheir

    koutheir Member

    Hello,

    First of all, I need to say I searched for weeks to solve this issue. I found no other way than posting a question. I hope someone could help me solve it. I checked the logs using "aLogcat" but nothing is relevant to the GPS. Any kind of help is welcome, I am not asking for a full step-by-step guide :)

    * Issue: GPS cannot find my location, even when kept for long periods under clear sky (20 minutes). I tried "Faster GPS" and "GPS Status" apps to debug the thing, but useless. I simply can't get a fix.

    * Infos:
    Device: SGH-I337M
    OS: Android 4.4.2 (Samsung Stock ROM)
    Baseband: I337MVLUFNE1
    Kernel: 3.4.0-1529758
    Build: KOT49H.I337MVLUFNE1
    Location: France

    * /etc/gps.conf
    ##################################################
    ENABLE_WIPER=1
    LPP_PROFILE=0
    DEFAULT_AGPS_ENABLE=TRUE
    A_GLONASS_POS_PROTOCOL_SELECT=0
    SUPL_VER=0x10000
    CAPABILITIES=0x37
    NTP_SERVER=fr (dot) pool (dot) ntp (dot) org
    INTERMEDIATE_POS=1
    XTRA_SERVER_1=(a link to xtra1 (dot) gpsonextra (dot) net (slash) xtra2.bin
    XTRA_SERVER_2=(a link to xtra2 (dot) gpsonextra (dot) net (slash) xtra2.bin
    XTRA_SERVER_3=(a link to xtra3 (dot) gpsonextra (dot) net (slash) xtra2.bin
    ERR_ESTIMATE=0
    DEBUG_LEVEL=4
    CURRENT_CARRIER=common
    NMEA_PROVIDER=0
    ##################################################

    Thank you :)
  12. ironass

    ironass Well-Known Member

    Hello and welcome to Android Forums koutheir! :)

    Sorry to see that you are having problems with your GPS fix.

    I see that you are in France and have the Samsung Galaxy S4, Black Edition, SGH-I337M minority variant which is primarily for use on the Canadian networks such as Bell, Rogers, Telus, SaskTel, Fido, etc: Whether this has a bearing on your GPS issue, I cannot say as I have the worldwide, GT-i9505 which is marketed for the European networks.

    I notice that you have GPS Status and Toolbox installed and wonder how many satellites you are getting a fix on outdoors?
  13. koutheir

    koutheir Member

    Yes you are almost right (except that my phone is white). I have no problem to install the international version of Android for GT-i9505 (kernel and system, at least). I tried doing that (I installed CyanogenMod) but it did not solve the issue, and that is the only reason I still tolerate the bloatware of Samsung. I am trying to find possible ways to debug the issue, logs, config files, just any possible trace...

    By the way, I am getting zero GPS fixes outdoor.

    Thank you for your warm welcome :)
  14. ironass

    ironass Well-Known Member

    I would strongly suggest that in light of the above that you take your phone to the nearest Samsung Service Point and ask them to check out your GPS antenna as it seems as though your problem is hardware related if you cannot at least see 1 satellite.
  15. koutheir

    koutheir Member

    I know that is possible, but I am trying to keep that as a last resort, so I will keep searching for a software solution for a moment...
  16. ironass

    ironass Well-Known Member

    Good luck with that idea but as per #7 in post #1, you should be able to pick up satellites and get a GPS fix with no data or Wi-Fi enabled in Flight Mode.
  17. koutheir

    koutheir Member

    Yes, I tried that for 20 minutes (while resetting AGPS data), and I got zero satellites :-(
  18. ironass

    ironass Well-Known Member

    Which is precisely what you would get with a damaged/broken GPS antenna. ;)
  19. koutheir

    koutheir Member

    I finally resolved my issue :)

    Current situation: GPS fixes 8 satellites out of 25 even between high buildings.

    Short solution: set the right CSC for your device.
    Advice: Always set the right CSC for your device, even if you happen to mess with it (which is arguably your own right as you own the device...).

    Long solution:
    - Backup your data and your apps. During the procedure, the device !!!WILL PERFORM A FACTORY RESET!!!
    - Root your device.
    - Open a terminal emulator on the device.
    - Type the following commands (let the terminal application gain root access when you get prompted):
    $ su
    # am start -a android.intent.action.MAIN -n com.sec.android.Preconfig/com.sec.android.Preconfig.Preconfig
    - You will get a window with a list of CSC codes. Select the one corresponding to your device and stock firmware, and push the button INSTALL.
    - The device will reboot, and !!!WILL PERFORM A FACTORY RESET!!!
    - That's all folks.
    - (Now go mess up things again, and again...)
  20. ironass

    ironass Well-Known Member

    Why would your CSC code have changed if you are running stock firmware for your model of phone? :confused:

  21. koutheir

    koutheir Member

    Because I played with the phone many times ;-) I installed all sorts of firmwares on it (from other countries,...). I am sure that one of those numerous flashes changed my CSC...
  22. deltaforce

    deltaforce Well-Known Member

    A quick question,
    Do these instructions apply to Google Play Edition phone as well (because I don't see the no. 1 i.e. Location Services in my settings).
  23. ironass

    ironass Well-Known Member

    The guide was not written for the GT-i9505G, Google Play Edition, which runs a separate, pure Nexus, firmware as opposed to the Samsung TouchWiz firmware.

    You should, in your phone's Settings, find, "Location", in the list and you should ensure that this is set to, "On", and, "High accuracy". This is the same as the Google Maps pathway.
    deltaforce likes this.
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