I have looked at some posts within this domain (e.g. iOS background fetch custom interval) and I am concluding that what I need to do is not possible.
I have an external device communicating to ios over bluetooth (NFC chip card reader). The external device goes to sleep if not pinged every minute (59 seconds).
When the app is in the foreground I can manage the pinging. When in the background I want to continue to ping. Is this impossible?
The ping operation is fast; it is just to send a message and I dont need a response back to ios.
(What works really well is the opposite, bluetooth communication can flow from the device to ios from the background. That is done via UIBackgroundModes in Info.plist to bluetooth-peripheral.)
Please note that I am feeding the iphone from external power in the application here. It is an industrial application; and the normal iphone usecase is not applicable.
Short answer, no. The best iOS offers is back ground fetch. But there is no guarantee when background delegate method is called. You can specify a timespan as a guide but it primarily based on how often the app is accessed.
https://www.raywenderlich.com/143128/background-modes-tutorial-getting-started
Related
I'm using BLECommander to connect to a bluetooth device in the foreground and my code is heavily based off this sample app. I believe my app would use both bluetooth-central and bluetooth-peripheral. Additionally, I would ping in the background every couple of hours to retrieve any new missing data. I am fine with connecting to a device in the foreground; I simply want to send messages to it in the background and retrieve data.
I have read the apple documentation on using core bluetooth to operate in the background.
If you read the apple documentation, you should know that your options are quite limited on iOS on what you can do in general when your app is in background.
However, there could be ways to achieve what you want. If you have control over the other bluetooth device you can make it change the BLE advertisement from time to time. When you scan on iOS, you will also get a scan result in background (but only once for a certain advertisement!) and can then connect to the device and read/write.
Hope this helps!
SO. Initial data:
Device Xiaomi Mi Band 1 or 1S
Device paired with iPhone
Xiaomi iOS app has option "Vibrate on incoming calls"
How they implement it? It continue works if you reboot device or force quit an app. It is unusual for default BLE background. Any ideas how this app handle events?
For people who vote for closing this question. This is a very interesting issue which require some specific knowledge about bluetooth and background. For example there are three bluetooth background modes: external-accessory for old-school non-ble blueooth, bluetooth-central and bluetooth-peripheral. I have done a lot of experiments about last two. But it does not work as you expected after documentation reading. I have found few questions about this topic here on SO. All of them report about pure predictable for bluetooth background. And after all hours on this issue you see on Mi Band and them official absolutely legal app in App Store. And this App keeps connection or has some other "magic" mechanism to handle calls and initiate reaction on device. At a minimum it is curious. Is it? At a minimum it is useful for developers who works with peripheral devices.
It looks like Apple Notification Center Service (ANCS) integration, not Bluetooth Background + Core Telephony.
The purpose of the Apple Notification Center Service (ANCS) is to give Bluetooth accessories (that connect to iOS devices through a Bluetooth low-energy link) a simple and convenient way to access many kinds of notifications that are generated on iOS devices.
Documentation
CategoryIDIncomingCall is about incoming call
In my application I need to log user status every 15 minutes. Is it possible if the app is in background (not killed)??
Currently I enables the Background location update. But how to call in each and every 15 minutes
While other answers are correct about background fetch, there is also another background option called VoIP, which apps like Skype use. In this case OS will wake up your application more frequently (even every 10 minutes if I remember correctly) and you can keep pinging your server in background. The obvious down side is that your app must have Voice over IP functionality, otherwise it would get rejected on the App Store.
All you need to do is add call setKeepAliveTimeout:handler: method and have voip enabled in background capabilities.
Just adding this for the sake of completion.
You may want to look at the Background Fetch capabilities added in iOS7 and beyond:
http://www.appcoda.com/ios7-background-fetch-programming/
https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html (Search for background fetch)
You won't be able to control the interval to exactly 15 minutes but you will find that this mechanism is the closest Apple will allow.
It is not possible to perform network calls at clearly specified intervals when your app is in background mode. You can tell your app to use background fetches
This article gives a great overview on the capabilities that you can do with this API. Basically it allows you to tell iOS that your app wants to perform networking calls in the background, however you can't exactly control when and how often iOS the network calls are going to be performed. iOS will schedule your network calls for you, and depending on how your app is used it will adopt the frequency with which it performs the requests. Documentation can be found here.
Here is my scenario ..
I have a device that advertises dynamic data per BLE protocol. There are multiple such devices operating for a user
Questions -
1) Can IOS scan such constantly changing advertising data or does it expect advertising packets to be pretty static?
2) Can we create a service that scans for such packets periodically - maybe 30s every 5 minutes?
3) Can such a service be automatically restarted during bootup without user intervention?
You cannot create a service on a normal (non-jailbroken) phone. Isn't even possible to distribute something like that (read the app review guidelines). Sure, you can scan for BLE data on whatever interval you want, but your app needs to be active, or it needs to be doing something approved by Apple for making connections to BLE devices in the background. Just be aware that like any other background app, iOS might suspend or terminate your app at any time, and there's nothing you can do about it.
What you have described is covered by the standard BLE background mode - it is covered in the Core Bluetooth programming guide.
You can set up a scan for specific service UUIDs and this will continue in the background. Your app will be launched into the background when a device is discovered.
The exact scheduling of the notification can't be controlled - but in my experience you are notified pretty much as soon as a new peripheral is discovered. Once you have discovered a device you can even initiate a connection as soon as it disconnects (ie goes out of range) - iOS will automatically reconnect to the device when it comes back into range
In order for the scan or pending connection to survive across reboots you must configure state restoration. This is also covered in the Core Bluetooth Programming Guide.
I am trying to build an app that will use the game kit peer-to-peer connectivity on the iPhone in order to find other people around you who are using the app and exchange information with them.
My question is- is it possible to use peer-to-peer connectivity when app is running in the background and when iPhone is asleep? If yes, do I need to do anything special?
Also, Will I be able to use geo-location, local notification and HTTP request when app is running in the background/ when iPhone is in sleep mode?
The background mode in iOS is very restrictive.
When your application moving to the background you have a "finite-length time" granted by the OS to let you finish the work properly (finish a download, save a file, close some connections, etc.). After that you can do nothing expect for some long tasks permit by iOS.
The only long task that iOS lets you run are the:
audio
geo-location
voip
newsstand
external-accessory
bluetooth-central
(Source)
So if you use the peer-to-peer connectivity over the bluetooth you may (in theory) do that in the background mode. This is the same for the geo-location.
However if you want use the local notification you'll need to register them before moving to the background, and the same for the HTTP requests.
For more information check this doc: App States and Multitasking.