[JollaC] GPS suddenly stops providing position fix

asked 2016-11-23 10:12:44 +0300

Giacomo Di Giacomo gravatar image

updated 2016-11-23 10:12:59 +0300

I have noticed the following behaviour on the Jolla C: When using the GPS for navigation, position suddenly stops updating and stays the same although the device is using several satellites (up to 9) to get the fix (checked with GPSInfo). The "still" position could be derived from non-GPS means but I could not check actual GPS NMEA output to get a more detailed diagnosis. The problem appears to happen mostly some minutes after starting navigation. I don't know if this problem is related to another one where the GPS appears to be performing a cold start beginning from 0 satellites used, producing a fix in some minutes. The latter problem appears not to be solved by a reboot, while the problem addressed in the question is. The issue happened both with 2.0.4 and 2.0.5.

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Comments

1

To get more information (including NMEA output) you can close down all maps/positioning applications, then ssh into the device, and do:

 ps axu | grep geoclue
 # ensure that no geoclue-hybris is running.  If one is, wait 30 seconds and it should quit itself
 QT_LOGGING_RULES="*.debug=true" devel-su -p /usr/libexec/geoclue-hybris

then quickly (i.e. within 30 seconds) start your mapping application. You should see the NMEA data in the console.

Note that a bug which was introduced in 2.0.4.x was recently fixed, which can cause satellite change information to be ignored in some circumstances; that fix should be in 2.1.0.x, you can see them by looking at the recent commits in https://git.merproject.org/mer-core/qtlocation/commits/mer-stable-on-5.6

chris.adams ( 2016-11-25 06:42:44 +0300 )edit