GPS Works Once (No GPS reconnect for 50 minutes)General


Last Updated: 2012-06-21 00:34:24
  1. pedro1977

    pedro1977 Well-Known Member

    After obtaining a fix for the GPS, if I disconnect manually or automatically (via an app closure) I have to start the gps again within 10 seconds in airplane mode or 25 seconds out of airplane mode to reconnect. If I dont reconnect within this time frame it will not reconnect for about 40-50 minutes. Rebooting or shutting down does not help. This renders the gps specific functions of the phone useless. This does not impact the location services provided by other chips i.e. wifi, cdma (3g data).

    If sats are only in view and no more than two are in use (a fix has not been obtained). I can end the session and restart it anytime without a reboot.

    This test was actioned in and out of airplane mode but never connected to the network i.e only searching for the network. Its unlikely being connected to the network would impact the outcome of these tests. If you wish to test your own device you should download and use GPS test from the app store. Having or not having AGPS data has no impact on the tests outcome.

    From reviewing logs and assuming this is not a hardware issue my supposition is it appears that when an active gps session with a fix is closed the device does a gps_cleanup. Upon reconnecting it attemps to call back this session against cache that no longer exists. After about 50 minutes a new session is initiated. This problem is somewhat highlighted in this example code. https://github.com/android/platform_...c0afbc92acd61c

    As we all have the same firmware it would be helpful if some forum members could test this themselves under the same conditions. It would indicate if this is a hardware /firmware/ root issue. If you do test it, indicate your results and whether your phone is rooted or not.

    I would also be interested in some insight into the cache cleanup commands in the gps.conf script file for this device. It appears GPS1_ CLEANUP_ENABLED=0 does not appear to work for this device. This example was pulled from another example http://forum.xda-developers.com/show....php?t=1338486 for another brand so maybe the commands are different with each device. I am also unsure if the gps.conf is read/executed too, per boot/ session/ agps call etc. I'm also unsure which permissions should be set.

    I have already factory reset the phone without success and tried other roms. I do not believe this is a hardware error as it wouldn't function in the first instance.

    Any insight would be appreciated.

    Peter

    Samsung R720 Vitality

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  2. np6s4x

    np6s4x Well-Known Member

    have one and can test but don't quite understand what you wanted tested never had any noticeable issues with the gps, it connects instantly for me on google maps, and continues to work even when i have no signal of any kind, (network, wifi, etc.) i downloaded that app and had between 3-8 sat. at any one time and not rooted, btw
    pedro1977 likes this.
  3. pedro1977

    pedro1977 Well-Known Member

    Thanks for doing the test, youve somewhat completed it. You need to put it in airplane mode, this will ensure all your chips are turned off (wifi, cellphone etc). Then its simple just turn on your gps, its the sat icon in the power control (or via gps on/off icon in the gps test app). Go to the app again and it will get a fix (accurracy lightens up), let it run for a minute after getting this fix.
    Close down the app for atleast 1 minutes (gps turns off automatically - flashing icon in notification bar disappears) then run the app again and see if you get a fix again - simple. If you dont mind I would appreciate it if you could do the test again, additionally if you ever root the phone (dont do it for this reason) then I would appreciate if you could run/ report your results for this too.
  4. Spz0

    Spz0 Well-Known Member Developer

    I've just ran multiple tests on my GPS m8.
    • Turned GPS on, fired up Maps for a location -- fine.
    • Turned off GPS
    • Turned On, Fired up Maps for location -- fine.
    • Turned off GPS
    • Airplane Mode on for 2 mins
    • Airplane mode off for 2 mins
    • GPS on
    • Fired up Maps for location -- fine.
    • Exit maps
    • Waited 3 mins.
    • Fired up Poynt for location -- fine.
    • Airplane mode on 2 mins
    • Airplane mode off.
    • Fired up maps for location -- fine.

    I think theres something wrong with your GPS module. Sounds like its hardware related m8 =\
    Let me know if theres anything else I can do.
    pedro1977 likes this.
  5. charssun

    charssun Well-Known Member

    GPS is working fine on mine, too. I put my phone in Airplane mode, turned GPS on and jumped in and out of Maps a few times. Maps always pinpoints my location correctly. Turning GPS off for a few minutes and then back on and jumping back into Maps shows GPS to still be working.
    pedro1977 likes this.
  6. pedro1977

    pedro1977 Well-Known Member

    Thanks for testing it.
    You should have had it in airplane mode for the whole time m8, otherwise it will get your location from 3g triangulation (if your logged onto cricket, esp. data) or via IP if your wifi is running.

    Looks like other posts may have susperseded this anyhow in that you may have got a silent software update over the network.
  7. pedro1977

    pedro1977 Well-Known Member

    Assuming that it was in airplane mode the whole time (no cell, 3g data, wifi etc), then i guess its either a hardware issue as inidicated or you guys have received a silent update over crickets data network. Thanks again to both of you for helping me with this.

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