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GPS loss at navigation

Hi,
is this tread still active? I’m fooling around w/ some cheap Android device and 4.4.2 which is known to have a flaky GPS (somewhat w/ A-GPS) and my routing stopped yesterday, most likely after a loss of GPS (No tunnel, no manual action).
Kurviger 1.10.3 and Kalman OFF, WiFi to mobile hotspot/4G OK; foreground
No routing 4 10++ min anymore, but zoom, pan of chart still OK, no error msg.
Sorry 4 being so unspecific, but loss of GPS while driving is hard to reproduce.
RGDS
hk

To clarify, routing and navigation are two completely different things. Navigation stopped?

User location stopped appearing on screen and navigation stopped due to no GPS signal?

Navigation stopped (and subsequently routing, if the position does not move anymore, there’s no navigation at the next crossroad??)
I can’t exactly tell, what was (or wasn’t) in the turn indicator window, but I remember very well that my position about 10m be4 the crossing stopped moving and remained stuck there, until I restarted. The route was still there, but I was @home and therefore can’t tell, if routing would have kicked in again.
hk
PS.: Just a little blind man’s idea 2help:
B4 I restarted, I took a look at the GPS w/ another program. GPS had no fix and no sats. It had to start from scratch, acquiring sats and fix. Looked to me, as if GPS had gone to sleep (may be due to signal loss) and wasn’t re-started by the App. or anything else, which would require Pos service.
just read,

This thread has reports for very old app versions, so mostly it’s irrelevant to present.
Well, I only had this the 1st time and on 4.4.2 which is “quite old”.
Don’t create an extra thread 4me. Iknow, what I’m doing here w/ 4.4.2 is “out of regular scope”, but since Schlesi had re-opened the case, and I just experienced something similar, I jumped on the band wagon.

(moved posts in new topic)

So seems GPS sensor stopped working.

Can search Android settings if there is some GPS sleep or something similar by the manufacturer.

And can try a different location service in app “Settings | Map” to see if GPS can be improved.

Hi,
sorry for the beginners advice, but isn’t there a status change notification call back for the Android loc service ?
hk

Do you mean an icon at notification bar when GPS is active and working?

No,
i was talking about real code, as described here
https://developer.android.com/reference/android/location/LocationListener.html
Unfortunately the onStatusChanged was depreciated and the “new” status variable
LocationProvider#AVAILABLE as well. Android is a maze, but may be YOU can find something similar.
RGDS
hk

With both location services (Android or Google) the operating system shows already an indicator for the GPS when enabled and working.

Sorry again, if I annoy you w/ my beginner’s knowledge, but I thought, the onStatus or onProvider… call backs could be used to detect if the service has gone and a re-initialize Location could be triggered.
I thought that the GPS service becomes unavailable (for whatever reason outside the App) and that the LocationListener inside the App sees all LocationHas… variables as false, hence it waits forever until these might become true again for available speed, location, height… etc. because the LocationListener cannot know, if the location is unavailable because of No Sats (tunnel), or if the service as such has gone dead.
Or onLocationChanged might even never been called again, if the service is dead.
Therefore I though, that the depreciated CallBacks could be used to restart the location service.

hk

Many devices don’t even call all listener methods besides the common one for the location changes.

Location service (Android or Google) starts and listens. Whether there are sensor reports depends then on device sensor quality, manufacturer Android changes, sleep settings, etc.

Hi,
I’m not yet entirely through w/ my testing, but I think I can give you something to chew on. While underway, I use my mobile phone as WiFi hotspot, in case re-routing is necessary. The problem of stopping Nav due to loss of GPS may be related to the fused location provider. While wired WiFi routers can provide a location as well as GSM radio providers, moving WiFi hotspot may not. Hence in case that there’s currently no GPS pos available, the fused location provider may try to get a pos from the moving WiFi mobile hotspot and gets trapped there. At least there are some stack overflow contributions regarding the issue. In this case, all Android devices like tablets w/out own GSM i/f, relying on moving WiFi hotspot may have this problem.
BTW Sygic, which I use as comparison on the same device gets trapped too; hence its not a specific Kurviger prob.
I’m now testing trying to nail the location service to “high accuracy” which should be GPS pure and avoid fused locations, but who knows, what Android is really doing…
RGDS
hk

There are 2 available location services in app “Settings | Map”:

  • Android: original location provider (using GPS in navigation)
  • Google: fused location provider (sources handled by them)
    Needs updated Google Play services or fallback to Android.

The active location service can be seen in “Settings | About | Info”.

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Not sure, how it really works! There are 2 places, where you can change. In my devices from Android 4.4 up to 8, you have at OPS level 3 choices: high accuracy (gps + wlan+bluetooth), power save (wlan + BT) and device only (GPS). Does Kurviger override these settings? and restore on app close? If I start the App and system settings was high accu b4, what will the App use and what will I see in system settings after 5he app has closed?
RGDS
hk

No, that is not app’s responsibility.

Above I described how Kurviger works in one of its two available location service modes.

Whether the GPS is enabled in the device, it really depends on device’s Android settings handled exclusively by user. And those settings can appear differently by Android version.

Just make sure that GPS is enabled before using Kurviger with one of its two location services.

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so my scenario is still valid. In case that the Android location mode is set at OPS level to high accuracy (GPS,WLAN,BT) and the GPS sensor becomes unavailable, Android may search loc in WLAN or BT. In case that none can deliver a valid loc, the Apps call back method LocationChanged will never be called and the App appears hanging, although it just doesn’t receive anymore loc updates. We don’t know if Android tries to restart the GPS services, probably not, as the APP does neither, and we are stuck forever! Sygic seams having implemented a watchdog timer for this. If the problem occurs, sygic shows the big blue planet, saying “I don’t know where you are”, and after a few seconds, it turns and zooms into the location and nav continues seamlessly.
RGDS
hk

As explained above depends also on which location service use in the app.

  • Android location service uses only GPS in navigation.
  • Google location service has a fused location provider.

Regarding Android internals, when GPS is enabled in one way or another in device settings, then if it’s lost, Android continues to search for it and will reconnect when finds satellites again.

Apps just need to keep listening continuously and the GPS messages broadcast when are available. That’s how all devices work all these years with all Android versions.

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