Add option for time-based background scanning as an alternative to "automatic scanning while moving" on non-play devices

[Lurux]

Description

Rationale

Currently, a user can contribute data in the background (without opening the app) in three ways:

• Using the quick settings tile. Needs manual intervention.
• Passively. May not be used often if the user otherwise rarely uses location-based apps.
• Via Google's Activity Recognition API.

The latter API seems blocked in GrapheneOS as per other issues, and is not currently implemented in MicroG, leaving non-play users who want to contribute data in the background without intervention with no good option (unless they often use location-based apps).

Suggestion

I suggest adding a third option, "Automatically try scanning from time to time", which would start scanning on a configurable interval, eg. every 10-60 minutes.

Suggested implementation

Behavior

When scanning is enabled by this mechanism, it should automatically stop if/when the device isn't/stops moving.

If "pause scanning on low battery" is enabled and battery is below the configured level, this mechanism should not enable scanning in the first place.

When this setting is enabled, the timer should automatically be started at boot.

I assume "automatic scanning while moving" has all these behaviors already implemented here (?)
If not, it might be worth upgrading said option to follow said behaviors

Additional information

Benefit

This should provide non-play device users with a battery-friendly way to continuously contribute data in the background, even if they don't have access to Google Services.

New request

• I have checked that a similar feature hasn't been requested yet

[Lurux]

Notes

Important

I have extensively checked related issues, leading me to the understanding that "automatic scanning while moving" does not currently work on any non-play device and that there is no battery-friendly equivalent solution for those users, but I didn't think to write them down to reference them here, sorry about that. I can add references if needed.

Although I don't know much about android development, I'd be happy to try implementing this if I get approval and a bit of guidance.

Related

I assume "automatic scanning while moving" has all these behaviors already implemented here (?)
If not, it might be worth upgrading said option to follow said behaviors

Please tell me if I need to open a new issue regarding this, if applicable.

[mjaakko]

This could be quite complicated to get working properly. Currently there is no mechanism for automatically stopping scanning when in an area that already has reports (see #11). Using GPS speed to signal when to stop scanning would not work reliably, because the scanning process would stop often when moving at slow speeds and then it would take a relatively long time until the timer kicks in. The automatic scanning feature gets a callback from Google Play Services when the device is not moving

Currently my recommendation for battery-friendly scanning is to change the Movement detection option to Motion sensor. This will make it possible to pause the GPS when there is no movement detected by the motion sensor, which should result in a significant reduction in battery consumption. This feature also uses passive location listener to make it more reliable, so you can use it to kind of achieve what you describe here if you have an app that polls locations regularly.

[Lurux]

Hmm, interesting. I think stopping scanning in areas with existing reports is out of scope for this issue, also considering the wifi and bluetooth beacons in a given location may have changed since last visited anyways.

Concerning this issue and the use of the motion sensor movement detection, maybe an additional toggle or fourth mode could be added, eg. called "Battery saving mode" or "Background scanning mode", which pauses scanning for eg. an hour when no movement has been registered for a while.

For example, my understanding is currently the GPS is off by default and will only kick in when the motion sensor detects, well, motion. Maybe we could add a timer in this mode such that even the motion sensor (and/or gps if applicable) stops for an hour when no motion has been detected for a while.

[Lurux]

Side tangent here, but could you confirm NeoStumbler only uses GPS and no network beacons to determine location when "prefer fused location provider" is off ? I notice that MicroG regularly reports incorrect locations when using BeaconDB, and amplifying such errors by including them in my reports sure would be counter-productive.

I was also scared away from using your suggested "motion sensor" movement detection mode as it states it might be unreliable on some devices, is there any way to get more details and check/troubleshoot if it happens on my phone ?

[mjaakko]

Side tangent here, but could you confirm NeoStumbler only uses GPS and no network beacons to determine location when "prefer fused location provider" is off ?

Yes, only GPS is used if fused location provider is not enabled

is there any way to get more details and check/troubleshoot if it happens on my phone ?

Not really, you just have to try it out

[Lurux]

Yes, only GPS is used if fused location provider is not enabled

Ok, thank you.

Not really, you just have to try it out

Ok. What would be the type of unreliability - would it be that the scanning doesn't kick in, or reversely that it uses too much battery if the sensor is too sensitive ?

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Regarding the previous comment above, do you think a toggle could be added such that all gps / motion sensor detection & tracking is paused for eg. an hour when no movement has been detected for eg. ten minutes ?

This would further help in providing users with an even battery-friendlier way to keep scanning in the background, and I reckon the pausing could probably be built off the existing "pause on low battery"'s existing implementation.

[mjaakko]

Ok. What would be the type of unreliability - would it be that the scanning doesn't kick in, or reversely that it uses too much battery if the sensor is too sensitive ?

The typical problem is that the sensor is not sensitive enough and then there will be relatively long gaps without scanning

Regarding the previous comment above, do you think a toggle could be added such that all gps / motion sensor detection & tracking is paused for eg. an hour when no movement has been detected for eg. ten minutes ?

I think an hour might be a too long time and using timers in general is difficult because there's so many different use cases. There are quite many cases where you stop for a while and then continue moving and would want to continue scanning.

How about using geofencing for this? E.g. if there's no movement for 5 minutes or so, then the scanning service is completely stopped and a geofence is registered to detect when the device has moved at least ~500m from the current location. The battery impact from the geofence should be very minimal, but this would allow restaring scanning quickly when you're moving again

[Lurux]

Hmmm, interesting.

Wouldn't geofencing involve the GPS being always active to function tho, hence acting essentially the same as the "location based" option for movement detection ?

Also this proposal targets people who don't rely on Google services, and I may be wrong on that but I seem to remember geofencing being implemented by said services than Android itself. I may be completely wrong here, so don't take that for granted.

Maybe a watered-down version of my proposal could be implemented instead, in the form of a "power saving" toggle, which would disable all gps and movement scanning for eg. just 5 minutes when the device has been stationary for a while. Do you think this could work out as an acceptable solution ?

[Lurux]

It might also be worth considering if it makes sense to turn the GPS on and off all the time [in motion detection mode, and/or if this proposal is implemented], depending whether GPS takes more resources to initialize instead of just staying on for eg. 10 minutes. Might be worth getting more information on that.