[Hardware] XA2 GPS - Trial to fix it for debuging

[Steve_Everett]

I don’t know how many times we’ve been through this loop, but I think it is now generally accepted, even by Jolla, that GPS issues on the XA2 are not down to a hardware issue. Common sense says that there are just too many people with Sailfish XA2’s who are suffering from unusable and lengthy fix times for all these phones to be suffering from individual hardware faults.

Since other OS’s on the XA2, including Linux derived ones like Sailfish, also work fine with GPS, that also pretty much rules out a general hardware design failure as well. I suppose there is the very remote possibility that the GPS hardware design of the XA2 is such that whilst it can work with everything else it can’t work with Sailfish, but I doubt it.

A while back I did a bit of testing on my two XA2’s - one SFOS and the other Android. For me, at least, these confirmed it was indeed a Sailfish issue:

GPS stopped working

I too am fairly sure it is not a hardware error. I have two Sony XA2s, both single sim H3113 models. One is on Sailfish Verla 4.2 paid version, the other is now on Android 9. Both were bought new and well looked after. Neither has been dropped, drowned or had any repair work done. The Sailfish XA2 has occasionally had to be returned to Android 8 prior to a necessary reflash after some serious problem made the software non-functional. The reason I have two phones is that the Android XA2 is a re…

[chazaq]

Totally agree. It is not the hardware.

[jollajo]

@Steve_Everett Sorry, I won’t agree that HW can be ruled out.

You state that GPS works flawlessly on XA with Android and derivatives, however it also worked well when Mozillas online positioning support was active. The problem came up when online positioning support was deactivated.

If you want to rule out HW issues, please verify proper GPS on Android, et.al. WITHOUT any A-GPS function activated, just plain GPS without prior / external knowledge.

[Steve_Everett]

@jollajo

If you want to rule out HW issues, please verify proper GPS on Android, et.al. WITHOUT any A-GPS function activated, just plain GPS without prior / external knowledge.

I thought I’d already done this test, and it was you who asked me to do it, here:

@jollajo

So may I suggest you deactivate online position lock on your Android phone and try out how GPS behaves?

@Steve_Everett

OK, it took 3 minutes to get a cold start lock (its a couple of weeks since I last switched the Android XA2 on) from being ‘nowhere’ (just a map of the world shown in Google maps) to a zoomed in setting of my house, on my road on the South Coast of England instead of a few seconds. So definitely slower, but still in a different league to how long it takes Sailfish.

unless of course ‘A-GPS’ is different to ‘online position lock’?

[vesa.s]

XA2 GNSS receiver is dual system recever GPS and GLONASS.
I think that it can also calculate position using single system.
And I think that GLONASS can do initial position fix faster.
And also it seams that XA2 devices that can’t do position fix, can still receive satellite signals and data.
Meaning that some unknown reason it just calculate own position.

[amaretzek]

As I alreadt said, when I move an X and an XA2 step by step with pauses inside my house, the XA2 allways looses signal first, way ahead of the X. So, how to explain that with software other that chip firmware issues? At least poorer S/N on the XA2 ist compatible with that.

[jollajo]

@Steve_Everett

I thought I’d already done this test, and it was you who asked me to do it, here:

You’re right, I forgot about that, however I think there’s a difference between Mozillas online location service and A-GPS. A-GPS deals with XTRA and/or SUPPL data which may be fetched by the SOC directly or fed from application processor.
So there may be a chance that it’s HW, maybe not. I guess we do not yet understand enough of the whole architecture. At least there’s too much confusion and at least Jolla could help us to sort that out.

[Steve_Everett]

Well if that data is fetched and passed to the GPS system purely in hardware then presumably it makes no difference what OS is used on top of that hardware? Either it should work with all OSs or none if there is a hardware fault.

If somebody can tell me how to disable these data feeds on Android then I will happily retest without them.

At the end of the day what users really need is for Jolla to come clean and tell us (and future prospective users who might be considering buying an XA2 to run SFOS) that (a) this problem is not fixable, or (b) this problem is fixable and the fix will be in release whatever, or (c) this problem is fixable but they have not got the resources to do it on such an old phone (but maybe community effort can fix it given a bit of help) , or (d) whatever. After all, we have had several years of this uncertainty now and still no light or dark at the end of the tunnel.

[OhneZ]

that’s absolutely right !
if this info would come from Jolla at least it would be clear.
Even if it comes down to switching to another Sony.
But this not knowing here doesn’t make anyone happy.
I also think that the different hardware versions of the XA2 could be a problem.
I also get a GPS fix on satellites with really bad signal.
Right now my XA2 is acting like my Amazfit GTR without A-GPS data. 10 - 15 min to GPS fix.

[Inte]

Even though GPS on the XA2 is quite slow compared to the 10ii it never took that long with MLS properly installed and configured.
I’m using MLS Manager | OpenRepos.net — Community Repository System

[ric9k]

Some engineer with GLONASS/GPS HW/SW knowlage should help. True.
I am convinced there is a problem stack sandwich: SW + HW.
Endless looping researches are often sign of multiple issues: one fixes the SW but sees no results because of the HW, and inversely. Or result change in an inconsistent way.

Try it: open, fix, test. In short term (24h+24h…) they definitely fix much better. I am waiting some more days without GPS use, to confirm for medium term.
ATM they fix between 1 and 7 minutes (mostly 3 or 4 min.) with W.Eu pos. pack. Each day.

@Steve_Everett

If somebody can tell me how to disable these data feeds on Android then I will happily retest without them.

True: must be compared what is comparable.

This is hard with Android. Could we suppose that Android comes with big and good GPS help data into the rom file?
Because:
Several times,I flashed android, unplugged the battery, booted, no connection at all except some seconds to set an exact time.
Then, I tested positioning with Gpscockpit and/or Gpstest. Both have a button to delete assistance data.
Even with all that un-helping actions, fix happens in 3 minutes in Android. I read on the threads that this should not be possible because almanach takes 12min. to download.

As said, average SFos fix on renewed devices is not far, most of the time, 3 or 4 minutes.

Headaches…

[phklrz]

Indeed, download of the entire almanach requires 12.5 minutes. But the gps receiver starts computing position before having received the entire almanach. According to the French wikipedia page on gps, typical cold start (no almanach data) time to fix is 2 or 3 minutes.

[phklrz]

I don’t know if there is a link with our problem, but even when I have a very good fix (horizontal accuracy ~ 10m, vertical accracy ~ 5m) the altitude given by gps (either cli gpscon, gpsinfo (direct85) or GPSTest (android) is quite wrong:
the altitude of my home is 210m, gps reports 260m. At workplace, real altitude 157m, gps reports 230m.

[ric9k]

Oh yes, I didn’t notice.
I sould be at 3M. my XA2 said 46M. (same ~10/5m precision)

[jameson]

GPS altitude value is by the design of the system not very reliable.

[phklrz]

But the vertical accuracy should reflect that.

[jameson]

That’s not very reliable too.

[ric9k]

8 days without GPS use for HW renewed devices (*marked)
High accuracy GPS setting (all devices)
Only half sky view (out the window, house behind me), clear sky

Now:
GPS Fix for devices 1* - 2* - 3 - 4:
58 sec. - 145 sec. - 223 sec. - 66 sec.
GPS used yesterday on device 3

Before:
Dev. 1 fix time before HW renewal: 5 and 15 minutes
Dev. 2 fix time before HW renewal: 10 and infinite time

note:
Tested with no wifi, no data, time not adjusted since 8 days for dev. 1 and 2
Jolla Positioning package installed on all devices.

* = HW renewed

---

The fix time is greatly improved after a HW renewal.
These results tend to show that hardware can be an issue, at least in some cases.

However, GPS settings still act strangely. “High accuracy” seems to work better although no online help is provided.
Indeed, on the daily used device 3, no gps fix was possible without this setting since /home was restored.

EDIT: The following is nothing. I tried to switch again and again. No changes.
/EDIT

If you guys could try to switch from

GPS settings > custom > On On Off

to

GPS settings > High accuracy

and make some tests, this would be interesting.

[vesa.s]

For GNSS satelite ids.
1-32 is GPS
65-96 is GLONASS
2xx is Beidou
3xx is Galileo

[4carlos]

@Steve_Everett

Well if that data is fetched and passed to the GPS system purely in hardware then presumably it makes no difference what OS is used on top of that hardware? Either it should work with all OSs or none if there is a hardware fault.

Yeah, i did it. Same XA2 but with LOS 18.1 : After the first cold start (6 minutes), GPS works outside in the same city in a few seconds. Indoor after about 2 minutes.

Settings : Without WLAN support and without Bluetooth support. AGPS does not exist. Ready to go in a few seconds. That answers for me the question, is it hardware or software?

It looks like cheese, it smells like cheese, it must be a cockroach.

@OhneZ

Right now my XA2 is acting like my Amazfit GTR without A-GPS data. 10 - 15 min to GPS fix.

I also always thought it could be due to different hardware revisions or changed board layouts because the messages here in the forum are different. Currently I find that other OS can solve a possibly existing problem better.