[Help Wanted]: startGeofences vs start

[renrutsirhc]

Required Reading

• Confirmed

Plugin Version

4.16.12 (also tested with 4.17.0)

Mobile operating-system(s)

• iOS
• Android

Device Manufacturer(s) and Model(s)

Samsung Galaxy s25+

Device operating-systems(s)

Android 14

What do you require assistance about?

Hi @christocracy,

The app I'm working on is a workplace sign-in solution. We utilise geofences for a site such as an office/university/construction site etc. to automatically check workers in when they arrive on site and check them out when they leave. Our two main requirements are accuracy of checkin/checkout detection and battery life.

My testing is a mixture of wandering around my neighbourhood on foot and commuting by train (I have geofences set up on various stations on the line I take to work).

I've been having some mixed results from the plugin:

• startGeofences with geofenceModeHighAccuracy is excellent - no issues
• start is also excellent - no issues
• startGeofences with geofenceModeHighAccuracy disabled - performs quite poorly. The symptoms of the problem are that it is unreliable as to whether the geofence events are fired (I'm using all three - ENTER, DWELL, EXIT ). ENTER is the most reliable of the three and fires most of the time. DWELL is rarely fired. EXIT is sometimes fired but often quite a long time/distance outside the geofence. I have noticed also in this mode that the plugin never enters the 'Moving' state (there is nothing in the logs showing the change and the onMotionChange event handler is also not fired. I can also see that there is no ActivityChange from still to walking/similar occurring (both in the logs and the event handlers not firing).

My questions based on all this are:

1. Is this normal behaviour for startGeofences with geofenceModeHighAccuracy disabled?
2. If it is, with regards to battery life, which is likely to be more efficient? startGeofences with geofenceModeHighAccuracy or start

[Optional] Plugin Code and/or Config

[Optional] Relevant log output

[christocracy]

Android geofencing is notoriously poor (Google it) when active location updates are not on. That’s why I introduced geofenceModeHighAccuracy, to the location api on during .startGeofences.

[renrutsirhc]

Thanks @christocracy - that seems to be what I'm seeing! Do you know which of startGeofences with geofenceModeHighAccuracy and start will give the longer battery life?

[christocracy]

Obviously geofenceModeHighAccuracy will consume more battery with .startGeofences by keeping location api ON.

.start() should consume more than .startGeofences()

[renrutsirhc]

OK - thanks. Is the behaviour where the plugin doesn't enter the moving state (and doesn't register activity change e.g. from still to walking) with startGeofences with geofenceModeHighAccuracy disabled normal? Or is this device specific (in a don't kill my app kind of way?)? NB - I forgot to mention - this was all testing with the app open on the screen.

[christocracy]

Device specific

[renrutsirhc]

@christocracy One followup to this, are there configuration properties that only apply when calling start and not startGeofences? e.g. I tested motionTriggerDelay today with startGeofences and it didn't seem to work. There were no events in the logs as described here: https://pub.dev/documentation/flutter_background_geolocation/latest/flt_background_geolocation/Config/motionTriggerDelay.html

[christocracy]

Yes, many options don’t apply for .startGeofences.

Does it make sense to talk about distanceFilter with .startGeofences? Of course not.

No, I can’t tell you off the top of my head which don’t apply.

[renrutsirhc]

@christocracy Are the docs incorrect then: https://pub.dev/documentation/flutter_background_geolocation/latest/flt_background_geolocation/Config/geofenceModeHighAccuracy.html. This states that distanceFilter does affect startGeofences? Or does startGeofences with geofenceModeHighAccuracy respect different config properties than startGeofences without geofenceModeHighAccuracy?

Apologies for the many questions - but unfortunately, the docs don't provide any clarity on this and these are important things to understand to choose the best configuration for this SDK. It would be great if the docs could be updated to clearly state which modes of operation each setting applies to. I'm sure this would help out other developers in the future.

For the time being, I need to know what effect the following properties have in each enabled mode:

Modes

• startGeofences
• startGeofences with geofenceModeHighAccuracy
• start

Config settings

• distanceFilter (+ elasticityMultiplier)
• locationUpdateInterval
• deferTime
• motionTriggerDelay
• speedJumpFilter
• stopTimeout