GPS stopped working

Did you flash directly to older Sailfish or did you use Android in between? I’ve had experiences where flashing to Android improves GPS for Sailfish for a little while.

I did a test today which seems to confirm an issue with the XA2.

I have an X which is still on 3.3.0.16 and an XA2 on 3.3.0.24.

I took them to a position about 150 km from the last GPS lock on and then launched Here WeGo.

The X which had no sim card inserted and no data connection took 2 to 3 minutes to get an exact location lock on and display a green location symbol.

The XA2 with a sim card inserted and with cellular connectivity took about 5 minutes to get an approximate location with a grey location symbol and another 6 minutes (11 minutes in total) to get an exact fix (lock on) and display a green location symbol.

While I was waiting for the XA2 to get a lock on I also started GPSInfo. GPS Info took 6 to seven minutes before showing any satellites in use.

It would seem the GPS in the XA2 isn’t working as well as it should.

3 Likes

No, I just resetted the phone to factory setting and updated to Torronsuo. I didn’t flash.
I only tried the satnav once, yesterday. It’s a mystery.

Indeed XA2 on 3.3.0.24 is not usable in real life for navigation. It takes 10-15 minutes to get location (high-accuracy enabled) . Huge step back :frowning: Is this linked to removed Mozilla services for GPS?

Yes, the Mozilla location services do not work since several months. Therefore it slows down position fix if Mozilla is enabled. As I had 3.3.0.24 (have now 3.4.0.24), GPS worked best in GPS only mode (and now it’s the same).

I have a feeling that “location parsing” from satellites doesn’t work properly as GPSInfo does show them like 0/15 or something like that for several or even tens of a minutes. So my guess is that satellites are received properly but the location isn’t calculated for some reason.

At least that’s how I it experience on my XA2 with 3.0.4.24 with high-accuracy enabled. I didn’t try without.

I think this line in GPS info

Satellites in use x/y

is y satellites are received in the moment
and x satellites are currently used for the calculation of the position.

The appearance of a number x >= 4 (the more the better) leads to a valid position fix. This must be satellites of the same system, e.g. GPS. Receiving e.g. 2 US GPS sat’s and 2 Galileo sat’s (=4 in sum) does not work.

2 Likes

I tested GPS on my XA2 today while picking the kids at school:
after acquiring signal at home, I could successfully drive to school (~20 min), switch off Pure Maps, then once back in the car, fire it up again, and drive back with GPS working all the time.

How long did it take to acquire the signal at home?

How long was it since you had used the GPS?

Was your home the last position you used the GPS prior to this use?

In my experience the problem manifests itself when the GPS is started at a different location to the last time it was used and/or there has been a considerable time between it’s use. In my opinion switching it back on as soon as you did and in the same location is not a true test to see how quickly the GPS acquires a signal.

I’ve just done another test using my Xperia X and XA2. I started Here WeGo, Pure Maps and GPSInfo on the XA2. GPSInfo was telling me 0/3 satellites.

I then turned on the X and started Here WeGo and Pure Maps. I then downloaded GPSInfo onto the X and then started that. Immediately it showed 2/5 satellites. Within a few minutes it was showing 11/32 satellites and Pure Maps and Here had a position lock, meanwhile the XA2 is still showing 0/3 and no position lock.

Both devices had Location set to device only mode.

How long did it take to acquire the signal at home?

a few minutes (i’d say 3 minutes)

How long was it since you had used the GPS?

I did a full reinstall of SFOS on my XA2, so never

Was your home the last position you used the GPS prior to this use?

see previous answer

In my experience the problem manifests itself when the GPS is started at a different location to the last time it was used and/or there has been a considerable time between it’s use. In my opinion switching it back on as soon as you did and in the same location is not a true test to see how quickly the GPS acquires a signal.

good point - i’ll active GPS in a different location and will report how much time it took to acquire the signal

so I did some tests today:

  • last known location at home. driving ~20 min, then booted my XA2 and launched Pure Maps. Took ~2 min to acquire signal.
  • shut down the phone, drove back once I had finished what I had to do, then once back home, i booted the XA2 and launched Pure Maps, and again signal was acquired pretty quickly (~2 min).

I’d like to hear the results if you repeat you’re test in a week a two.

i can certainly do that :slight_smile:
will report

How far apart are the two locations? Also what time frame between each time you turned on the GPS?

I suspect part of the problem is to do with the GPS almanac and the GPS receiver knowing which satellites it is looking for. For example turning the GPS receiver on only a short time period after it was last used and or in a similar location means the same space vehicles (satellites) will most likely be the same ones as used previously or at most most of them will be. The almanac data is still up to date and the GPS will acquire its location more quickly.

I don’t consider 2 minutes to be a quick time frame for acquiring a position. My Samsung Galaxy Tab does it in a matter of seconds. Even my old N9 phone and N1 tablet only take about 15 seconds.

There is work to be done to get the GPS in the XA2 at least to acquire more quickly.

i am aware that majority of the issue is caused by mozilla location services not being available for this use case anymore, but still… i haven’t been able to get gps lock in a few days now, and my companys other phones can get a lock in the back yard of my work place.

it’s really frustrating to try and navigate to a customer without guided gps, but i take it as a learning excercise in good ol’ map reading. it would be nice to have a functional gps on the go… i can’t recall if xa2 series supports glonass or galileo, but i hope the next official community device will…

you might be wondering why i am writing in lowercase; i’m using a bluetooth keyboard to write this witn my xa2 ultra running sfos 3.4, and the shift key doesn’t do anything - for starters.

You mean ephemeris data, not almanac. It’s unlikely that satellites are added or removed in a timeframe of some hours.

No I mean almanac data.

Ephemeris data corrects ephemeris error and is used to refine the GPS calculated position.

Almanac data is information about the whole constellation, the satellites in use and their orbit data. The GPS receiver uses this information to speed up the acquisition of satellite signals when it is turned on. It stores this information when it is switched off. If the GPS is switched off for an extended period or is moved to a location some distance from where it was last used, the stored almanac data is out of date and not useful in helping the receiver acquire a signal and thus it takes longer to show it’s correct location.

In my experience with GPS, new almanac data are only required when moving hundreds of kilometres from last fix (e. g. when receiving a GPS receiver from an overseas manufacturer) or after many weeks of shutdown. After all, all other GPS receivers take little time to get a fix even without A-GPS, except the XA2.

Is there some way to perform a cold start on XA2?

I wish I could remove the battery, but I’d rather not rip off the glued-in display assembly. Dammit this current trend! It would help with various Bluetooth hiccups, too!