We are in the process of developing Minder app for obVus (https://www.obvus.me/) which focuses on developing user-friendly products to change behavior and condition healthy habits.
Minder app (https://apps.apple.com/us/app/minder/id1437980397) allows you to check in with how you are feeling throughout the day. Minder tracks healthy posture stats, wear time, steps, mindful minutes, heart rate, goal, and Me/Mo progress which are all visualized on our intuitive, user-friendly dashboard. Minder syncs to Apple Health to keep all your vital health data in one place.
We are using Apple Watch and Airpods as wearable devices to track postures. We would like to incorporate Airpod posture tracking when Minder app goes to background!
Our team did research and we found that Air pods automatically get disconnected when we put the app to background by its default behaviour. We are automatically reconnecting it when we launch the minder app to foreground.
There are only limited number of background execution modes our app can support that enable it to run when in the background, such as playing audio, receiving location updates, or processing scheduled tasks etc. Here is the apple reference doc for the background services that our iPhone, iPad, Apple Watch, and Apple TV apps require to continue executing in the background: https://developer.apple.com/documentation/xcode/configuring-background-execution-modes
In the case of Apple Watch, this is possible since the minder app uses a workout session to track a user’s activity on Apple Watch but such mechanism is not available in AirPods
Can you please help us on this? Is there any mechanism to track user’s postures by using Aipods as sensors while the app goes on background . Can you please guide us so that we can incorporate Airpod posture tracking when our Minder app goes to background.
You can start a HKWorkoutSession to keep your Watch app to continue executing code in the BACKGROUND (For Watch)
Or start a Location Updating that allowBackgroundUpdate = true (For both Watch & Phone)
The biggest issue is High Power Consumption.
Here are some tips that you can apply to save battery for Watch/Phone.
When using HKWorkoutSession, start it and then pause it after 1 second to save battery.
When using CLLocationManager, start it after set distanceFilter = 3000, desiredAccuracy = 3000. It is like you just wanna run app in Background not updating location. With long distance filter and low accuracy, battery consumption rate will be very low.
Avoid running too many timer instances.
Limit the I/O usage
Related
Because the apple doc is quite vague concerning this point :
Upon being woken up, an app has around 10 seconds to complete a task
Does this mean that after 10 sec the app will go back to its "suspended" state ? Theoretically, is it possible to "force" the app to stay awake after these 10 sec ? (private app).
In my case the device would be connected to a car.
Does this mean that after 10 sec the app will go back to its
"suspended" state ?
If you read carefully :
Upon being woken up, the app has around 10 seconds to process the
data. Ideally, it should process the data as fast as possible and
allow itself to be suspended again. However, if more time is needed,
the app can use the beginBackgroundTaskWithExpirationHandler: method
to request additional time; it should do so only when absolutely
necessary, though.
Apps generally awake by Background modes(like location service, audio, push notification and so on) and for some modes like location service it will stay awake until the location data is being captured and for some, it doesn't stay awake for much time like push notification. So it depends on the task that is being performed. For Bluetooth, if it's connected with another Bluetooth device then it will stay awake.
Theoretically, is it possible to "force" the app to stay awake after
these 10 sec ? (private app).
Yes, it's possible.
Each of the preceding modes lets the system know that your app should
be woken up or launched at appropriate times to respond to relevant
events. For example, an app that begins playing music and then moves
to the background still needs execution time to fill the audio output
buffers. Enabling the Audio mode tells the system frameworks that they
should continue to make the necessary callbacks to the app at
appropriate intervals. If the app does not select this mode, any audio
being played or recorded by the app stops when the app moves to the
background.
Note : If you need it for your private app then you can check this here. Your app will be rejected if you add the solution and apply for appstore.
In XCode, go to your project->Capabilities->Background Modes and mark the Background Modes to On. Mark also Uses Bluetooth LE accessories:
Apps that work with Bluetooth peripherals can ask to be woken up if
the peripheral delivers an update when the app is suspended. This
support is important for Bluetooth-LE accessories that deliver data at
regular intervals, such as a Bluetooth heart rate belt. You enable
support for using bluetooth accessories from the Background modes
section of the Capabilities tab in your Xcode project. (You can also
enable this support by including the UIBackgroundModes key with the
bluetooth-central value in your app’s Info.plist file.) When you
enable this mode, the Core Bluetooth framework keeps open any active
sessions for the corresponding peripheral. In addition, new data
arriving from the peripheral causes the system to wake up the app so
that it can process the data. The system also wakes up the app to
process accessory connection and disconnection notifications.
For more detail you can refer Apple documentation.
Try this:
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];
I need to make an app that records heart rate data in near real time and send this data to a server as soon as possible.
First I took this approach: Watch os 2.0 beta: access heart beat rate
In fact it is working fine. There is new heart rate data in the HealthKit every five seconds. But now I have the problem that I can't sync that with a server.
My first approach was the Watch app. The watch was sending data to a server. That doesn't work because as soon as the screen turns black on the watch, it stops sending.
My next approach was to query the HealthKit on the iPhone every five seconds for new data. This works, as long as the app is in foreground.
Then I saw that there's some kind of background functionality that watches the HealthKit itself and revokes the app from background and you can do something.(enableBackgroundDeliveryForType) This doesn't seem to work for heart rate (the Apple Documentation says for things like steps this doesn't work, I guess heart rate is one of those).
I'm stuck now. Do you know how to it? I would need some background task that is executed every 5-10 seconds on the iPhone. That seems to be impossible
UPDATE
As noticed by #BootMaker, Apple made background mode available for HKWorkout apps in WatchOS 3, so it's working now. You have to run a HKWorkoutSession and this will keep your heartrate delivery in real time even when the app is in the background (dark screen on watch)
The closest you are going to be is while the watch app is open.
Why I'm stating this?
There are two HealthKit's Database (one at the iPhone and another at the Apple Watch). When they sync is arbitrary and decided only by the O.S.
The closest you are going to be to real time is when you don't have any password locking your screen in iPhone or Apple Watch.
Either way, there's no guarantee that the sync will happen every time a new measure is added to Apple Watch's HealthKit
The only way to force the Heart rate sensor into working in real time is via workouts or observer while your Apple Watch app is in FOREGROUND.
Background delivery is NOT available for Apple Watch apps.
Watch OS 2 request the sensor to measure automatically (in background) every 10 minutes minimum.
There's no other workaround, if you need real time for longer periods, or while the user is not using your app, you will need to use an specialized wearable.
If anyone still need to get heart rate or other data in real time. Use this solution:
Develop an apple watch app/extention
In watch app, using HKHealthStore, HKWorkoutConfiguration, HKWorkoutSession, HKLiveWorkoutBuilder to create an Workout. After create workout, your watch app will get heart rate in real time.
Using watch kit connection with WCSession to send data to iPhone app.
Enable background mode both in apple watch and iPhone.
I tested, even app terminated, we can still get heart rate (I used Local notification for posting heart rate data for debugging)
In an iOS app, by enabling the flags for VOIP, Audio playback, Location, Bluetooth LE accessories, News stand etc, we can run the app in background. But I've a requirement to create a library/framework that will make the app run in background as well as capture the accelerometer updates and log them to a file.
For that purpose, I enabled "Audio Playback" in the background, and playing a silent file in continuous loop so that app will continue to run in background. At the same time, I'm able to capture the accelerometer data as well. I'm using Core Motion framework for the same and its working perfect.
I would like to add one more point, my app has location tracking enabled to deal with beacons integration.
I want to know if its valid to follow such procedure and will Apple approve it during the review process? Has any one faced this kind of challenge ever?
As you guessed, the only way to access accelerometer data in background is with an active background mode. But...
Apple will NEVER accept your app if it declares a background mode without any feature actually using it (not just technically like your silent sound, but an actual feature that your user is aware of)
If you decide to implement a feature that actually use a background mode (like location or audio playback for example), don't forget that you will also drain your user's battery.
Conclusion:
Explain to your client that Apple's restrictions prevent you to do that and have the requirements updated
or
Find another feature that will need to use one of the background modes
I am developing an iOS (7.0+) application for fitness (running) that uses the users GPS location, does a small calculation and transmits the data to a Bluetooth Low Energy (4.0) watch. This process needs to be happening in the background, even when the user locks their iOS device.
I have implemented the following background modes as well:
App communicates using CoreBluetooth
App registers for location updates
I have successfully been able to get everything to work well, except for after a certain amount of time (ex. 2 hours) when the device is locked, the iOS device stops updating the location because I can see that it is no longer sending updating GPS values to the Bluetooth watch. I then have to unlock the device, re-open the app and location services works as it should again.
Does anybody know how to keep location services running the whole time in the background (device locked) without it suddenly stopping the location updates after a certain amount of time? If possible, an efficient solution would be preferred that does not drain the battery too much more than it normal would for using GPS.
Most important: make sure you are setting pausesLocationUpdatesAutomatically to NO before you start the CLLocationManager (see docs).
To minimize battery usage you should also use deferred location updates (more details on SO). This allows the CPU to sleep and save battery while the GPS chip collects location updates for you. It periodically dumps them to the CPU. This may not be for you if you need to update the watch once a second, but if you can update it every 10 or 20 or 30 seconds it will save that many CPU wake ups.
I am working on a sports app that uses GPS and OpenEars text-to-speech. The app delivers speed and other GPS info to the user audibly (via earphones) so the user (skier, cyclist, etc) can get the GPS info without looking at the screen. In order to save battery life, I would like the app to run in the background with the screen off. Is this possible with IOS? I tried setting "Required backgrund modes" for both GPS and audio, but my app quits working when the screen is off.
thanks..
One one to get around it is to have a silent audio file playing, when there is no audio, it might get your app rejected in the app store though... here is a question that talks about the silent audio file playing to keep in the background... It might get through app store approval in your situation since it is an app that relays on audio as one of its main functionalities..
You can subscribe to GPS info change notifications and your app will run when something needs to be updated. Check this.
Please note this sentence:
"If you leave this service running and your application is subsequently suspended or terminated, the service automatically wakes up your application when new location data arrives. At wake-up time, your application is put into the background and given a small amount of time to process the location data. Because your application is in the background, it should do minimal work and avoid any tasks (such as querying the network) that might prevent it from returning before the allocated time expires. If it does not, your application may be terminated."
There's no way to do it as service except some special cases provided by ios. But you can simulate it. This post answer how to:
https://stackoverflow.com/a/19121250/2835520
I hope it's gonna help!