Bluetooth connection on Android ICS not possible

Question

i'm writting an app which sends byte codes from a tablet to a µ-controler. Everything worked fine on the Lenovo A1 (Androi 2.3) and Samsung Galaxy Tab 7 Plus N (Android 3.2). Now i'm having issues with the new Samsung Galaxy Tab 2 (Android 4.0).

I'm able to pair with the Bluetooth antenna (which is connected to the µ-controller and communicates over the serial protocol). When I start the app I'm asked again to enter the password and to pair. After I enter the pairing password my main layout is visible but a connection isn't established.

The LogCat in eclipse tells me:

06-19 16:00:20.656: V/BluetoothSocket.cpp(3189): availableNative
06-19 16:00:20.664: V/BluetoothSocket.cpp(3189): abortNative
06-19 16:00:20.664: V/BluetoothSocket.cpp(3189): ...asocket_abort(49) complete
06-19 16:00:20.664: I/ActivityManager(185): No longer want com.google.android.partnersetup (pid 3220): hidden #16
06-19 16:00:20.671: V/BluetoothSocket.cpp(3189): availableNative
06-19 16:00:20.671: V/BluetoothSocket.cpp(3189): destroyNative
06-19 16:00:20.671: V/BluetoothSocket.cpp(3189): ...asocket_destroy(49) complete
06-19 16:00:20.679: D/KeyguardViewMediator(185): setHidden false
06-19 16:00:20.679: W/System.err(3189): java.io.IOException: socket closed
06-19 16:00:20.679: W/System.err(3189):     at android.bluetooth.BluetoothSocket.available(BluetoothSocket.java:370)
06-19 16:00:20.679: W/System.err(3189):     at android.bluetooth.BluetoothInputStream.available(BluetoothInputStream.java:40)
06-19 16:00:20.679: W/System.err(3189):     at java.io.BufferedInputStream.available(BufferedInputStream.java:114)
06-19 16:00:20.687: W/System.err(3189):     at ebs.alphadidact.control.ReceiveThread.run(ReceiveThread.java:79)

Further more is the LogCat receiving a thousand times the message:

V/BluetoothSocket.cpp(3189): availableNative

So as I searched in the web i found a few guys with a similar problem but no solution. Does someone know something about this issue?

Maybe it is a compability problem between the antenna and android 4.0. I don't think that the error is in my code because as I said the same code is running on older android versions perfectly.

Answer 1

Ok, I found out what the problem is. I'm not sure if it is just a Samsung problem or an Android ICS problem.

I tried to connect to the antenna as usual by using (to get the Socket):

clientSocket = device.createRfcommSocketToServiceRecord(MY_UUID);

Well it seems that it doesn't work out with my antenna and Tablet setup, so I tried:

clientSocket = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);

This does work. Ther first option forced the system to unpair the antenna and later ask for pairing again.

Answer 2

Actually creating an insecure socket is the same as connecting two unpaired devices. This is clearly not the best way to handle it.

I have found that Android tries to repair to the device, and then it rejects the pairing response. After this bizzare behavior, it will accept the next connection attempt!

I also tried the Android bugtracker: Bluetooth RFCOMM Server Socket no longer connects properly to embedded device on ICS 4.0.3.

Still waiting for a response...