I am working on the android application. In this application i have to connect to the ble device. I want the application connected to the ble device when the application is in background .
The answer is to have at least one Foreground Service https://developer.android.com/guide/components/services.html#Foreground in your process that uses BLE. That will make Android keep your process alive.
Related
I am working on a mobile app that connects to accessories over BLE. The app runs on Android as well as iOS.
I have a Raspberry Pi that is running a BLE server app.
When my Android app tries to connect to Pi over BLE, the connectivity just fails. I see a system notification popping up that Bluetooth connection failed because of an invalid pin or passkey.
However, my iOS app seems to connect just fine. There is no PIN or passkey requested.
I have tried Android testing with Pixel 2 as well as Pixel 3. The OS version is 10.
My Android app used to work fine until a few months ago. I feel it must be a recent change in Android OS.
I am wondering if anyone else has seen such a problem. Thanks.
I have built an iOS app that uses corebluetooth, and an android app that starts avertisement via GATT server.
So Android devices only discover other androids and iOS devices.
And iOS devices discovers other iOS' only.
The question is how to advertise data from android so iOS devices can discover it, or is there any way for iOS device to scan regular bluetooth devices except for MFi program?
if you had any experience with connecting these two OS via bluetooth, please let me know the ways on how to do it.
I'm workig on an issue where my device running Linux with bluez is connected to a mobile phone over bluetooth. It also communicates to the phone over BLE with an android application. What I want is to disconnect the legacy connection while keeping the BLE connection active. I tried with org.bluez.Device1 interface with method DisconnectProfile(string uuid). Is there a way to get a list of registered UUIDs which I can use to disconnect the ones related to legacy connection while keeping the GATT profile active?
After days of research and trial and error my colleagues and I have to hope that the StackOverflow community has a working solution.
We got an Android Smartwatch. We developed an app which acts as the BLE central. The App shows a QR-Code encoding an UUID which is unique for every Smartwatch. While showing that QR code it's actively scanning for a device advertising a service with that UUID.
We also developed an iOS app which can scan that QR code and start advertising with the service UUID it received. The Android Smartwatch then connects very quickly to the iOS device.
One purpose of the Smartwatch is to show push notifications from the iOS device. So when the connection is successfully established, the Smartwatch-App subscribes to the ANCS Data Source and Notification Source characteristics. This initiates "Just Works" pairing, so you just have to click on "Pair" on the iOS device. Afterwards you have to allow that iOS notifications are shared to the Smartwatch and then the Smartwatch successfully receives notifications.
ANCS is also the reason why the iOS device MUST BE in the peripheral role.
Until here everything works fine.
When the user leaves the bluetooth range or dis- and enables bluetooth on the iOS device, an automatic reconnect should be triggered. It DOES reconnect when the iOS app is in foreground. Unfortunately it DOES NOT work when the iOS-App is in background. This is probably related to the fact, that the iOS device is not advertising with the required UUID when the app is in background as described in the CoreBluetooth documentation:
All service UUIDs contained in the value of the CBAdvertisementDataServiceUUIDsKey advertisement key are placed in a special “overflow” area; they can be discovered only by an iOS device that is explicitly scanning for them.
We tried many different ways to reconnect from the Android Smartwatch to iOS. From my understanding it should be working when making the first connectGatt with autoConnect=false and when the connection is lost, calling connectGatt on the lost device with autoConnect=true, but it never reconnects. At least not within 15 minutes. Scanning again also wouldn't work, as the UUID is not advertised in background anymore.
We also tried to additionally let the Android device act as peripheral, so the iOS can connect to it. After connecting we wrote data to an "INITIATE_ANCS"-characteristic and let the Android device call connectGatt on the device which was passed to onCharacteristicWrite. This led to interesting behavior:
- The connection was working, we could read a Smartwatch-Characteristic from iOS.
- When subscribing to the ANCS characteristics, it initiated pairing. But instead of "Just Works" pairing it showed a 6-digit code on the iOS device which we had to type onto the Smartwatch.
- The pairing was inititated on every new connect and it always created a new device in the systems device managers on both Android and iOS.
- The pairing WAS NOT inititated when the iOS app was in background.
We really did a thorough research and couldn't find a solution. Did we understand something wrong on how BLE for iOS and Android works? We really hope to find an expert here that has the knowledge what has to be done to make the reconnect work.
Edit:
The Android device is running on Android 5.1.1 and currently it's no option to update.
The iOS testing device is running iOS 13.3 and it should be compatible with iOS 13+
I'm creating a watchOS application. The app should connect to a BLE tag, which sends distance values to the apple watch. If the distance falls below a given value, the application should give some feedback to the user about this.
Reading about core bluetooth and background tasks, it doesn't seems like it's possible. If I'm correct, when the application is suspended, it will no longer receive data from the BLE peripheral. How should I approach this task? Is it possible to run an application like this for 8 hours in the background? I can't find any more information about this, and it seems like it's impossible.
There are restrictions to WatchOS apps using Bluetooth in the background, the main being:-
The minimum connection interval is 30ms instead of 15ms (for iOS
devices).
The Apple watch can only operate as a central device.
The Apple watch can only be connected to two peripherals at one time.
The peripheral gets disconnected when the app goes into the background.
More details about this can be found in the following links:-
https://www.raywenderlich.com/336-core-bluetooth-in-watchos-tutorial
https://developer.apple.com/videos/play/wwdc2017/712/
The only exception to this is if you use the HKWorkoutSession. More information about this can be found here.
I hope this helps.