GPS tracking in Background - Edge Hack (Not Devel, Stable, RC)



  • @ernest Yes I already allowed the terminal to run in the background.
    test_gps shows 'init gps interface' and the program shows 'Waiting for satellites' but both get no position, while Pure Maps has GPS reception and shows the position on the map. Foreground or background doesnt matter. It looks like the terminal does not get access to the GPS?
    I switched from stable to RC without any change. I use it on a BQ Aquaris E4.5 Ubuntu Edition.



  • Try to let the phone outside for 5-10 min.
    If test_GPS doesn't work for you, then my app will not work.



  • GPS reception is not the problem, the app Activity Tracker is working and recording. I switched now the Activity Tracker to run in the background and it seems to keep running in the background. So I can navigate with Pure Maps in the foreground and record the track in the background. But as soon as the screen gets locked all the apps are stopped? Not sure, I will keep testing ... but if I play music in the Web Browser and the screen locks, also the music stops.
    It looks that in the case the UT phone should be my only phone I will have to reactivate good old Garmin Foretrex 401 for track recording.



  • Yes app not in foreground doesn't get GPS signal, see my request there : https://github.com/ubports/ubuntu-touch/issues/1067



  • I can't confirm this. I allowed Activity Tracker to run in the background in UT Tweak Tool and started track recording in Activity Tracker. Then I started Pure Maps to navigate and switched apps from time to time. Most of the time I had Pure Maps in the foreground. At the end I had a complete track in Activity Tracker.

    So this means, that Activity Tracker has GPS reception and works in the background (if allowed in UT Tweak Tool) in my case.



  • Another test showed again the problem with the locked screen. In my test Activity Tracker did not continue recording, once the GPS reception was lost shortly in a building, also GPS reception should have been good again after the interruption. Only after unlocking the screen it continued track recording.



  • Hi @ernest,

    I just had a look at the Utrack.py and made the following change (line 183), which made the code run on my phone:

    if re.search("^longtide", line): #longtide bug in test_gps
        try:
            long = line.split()
    -       if re.match(".\d+.\d+", long[1]):
    +       if re.match("(?:\d+(?:\.\d*)?|\.\d+)", long[1]):
                longitude = long[1]
            else:
                subprocess.Popen(["truncate", "-s", "0", temp_file], shell=False)
    

    You are trying to match a floating point number here, right? Following this post it is apparently better to use "(?:\d+(?:\.\d*)?|\.\d+)". I've made a pull request.

    I hope this does not break other things. On the my phone it works..

    Here is the click if someone wants to test:
    https://drive.google.com/file/d/1AADkOrVwV-YvTo00XtHnC997e3gRNIi0/view?usp=sharing

    Best,
    Hendrik



  • Thanks for the pull request,
    I'll not be able to test it prior end of august 😕 (My goods and spare phone are in transit).

    Let see the feedback of others.



  • For me the fix seems to work. I am travelling by bike since more than a week and a combination of OSM Scout Server, Pure Maps and Utrack does a very good job guiding and tracking me. The error did not occur again.

    However, I realized that two fuctionalities would improve Utrack a lot:

    • Automatic saving of the track every few minutes in order not to loose the hard work of a day once the battery dies 😃
    • A possibility for pausing/resuming the tracking

    Do you think this would be possible without deteriorating the battery performance?



  • Thanks for testing, I got back my Nexus 5. I should be able to look at it soon.

    The aim of this wrapper was to enable simple GPS background tracking, but not pretending to have a full feature app. I'm not going to add functionality on a "hack" even working. It would be better to enable on Utouch the GPS background then we could start thinking on improving apps (like Activity Tracker).
    We need visibility there : https://github.com/ubports/ubuntu-touch/issues/1067


Log in to reply