java.io.IOException: read failed, socket might closed or timeout in OpenSerialDevice

[harry1453]

java.io.IOException: read failed, socket might closed or timeout in OpenSerialDevice

[harryjph]

Could you perhaps provide a stacktrace of the exception that was passed to onError?

[WimVriend]

Hello Harry,

Thanks for your reply. Here is the stacktrace of the error:

D/BluetoothRunnable: onError, error=java.io.IOException: read failed, socket might closed or timeout, read ret: -1
W/System.err: com.harrysoft.androidbluetoothserial.BluetoothConnectException: java.io.IOException: read failed, socket might closed or timeout, read ret: -1
W/System.err: at com.harrysoft.androidbluetoothserial.BluetoothManager.lambda$openSerialDevice$0$BluetoothManager(BluetoothManager.java:66)
at com.harrysoft.androidbluetoothserial.-$$Lambda$BluetoothManager$fVpVBc1L4ZQfbGyxU14GY2nVwzg.call(lambda)
at io.reactivex.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:44)
at io.reactivex.Single.subscribe(Single.java:3220)
at io.reactivex.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:89)
at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:571)
at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:154)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:269)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.io.IOException: read failed, socket might closed or timeout, read ret: -1
W/System.err: at android.bluetooth.BluetoothSocket.readAll(BluetoothSocket.java:900)
at android.bluetooth.BluetoothSocket.waitSocketSignal(BluetoothSocket.java:859)
at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:535)
at com.harrysoft.androidbluetoothserial.BluetoothManager.lambda$openSerialDevice$0$BluetoothManager(BluetoothManager.java:61)
... 13 more

[WimVriend]

Hello Harry,

Any ideas?

[harryjph]

Sorry for the delay in responses! Been quite busy and not in a good headspace to work thanks to current epidemic.

It looks like the exception is being thrown when you try to connect:

https://github.com/harry1453/android-bluetooth-serial/blob/v1.0/androidBluetoothSerial/src/main/java/com/harrysoft/androidbluetoothserial/BluetoothManager.java#L61

It looks like the connection is failing. Have you managed to get this library to work for you with other devices?

[WimVriend]

Hello Harry,

Thanks for your answer. I try not be be impatient, but I fail sometimes :)

I have not tried to connect to any other Android device yet. Of course the idea is, to be able to connect with any kind of Android phone...

[harryjph]

Sorry, when I meant device I meant a bluetooth device other than your PC, like a bluetooth serial module

[WimVriend]

Hello Harry,

No, I have not tried to connect to any other bluetooth device (don't have one).

To be honest: I have abandoned my effort to implement bluetooth. I managed to get the ADB working and I will go with that. Even when IMO both Apple and Android fail to deliver decent USB support...

[harryjph]

Okay, sorry you weren't able to get it working, this seems like a very strange issue...

I would also suggest running a server that listens on a TCP port on your PC, and then connecting to this on your phone via WiFi - this would provide a realtime wireless data stream between your phone and PC, with much better range than bluetooth, but would require you to enter your laptop's IP on your phone and have the devices on a WiFi network... Just an idea! 😄

[WimVriend]

Hello Harry,

Thanks for your thoughts!

Actually, the Bluetooth (or now, USB) solution is meant as 'secondary' connectivity option. I have already implemented a Wifi solution using UDP (it is not really necessary to receive all packets, but latency should be low)

[harryjph]

Ah okay, if I get the time I'll try getting my phone connected to my PC via bluetooth and see how it goes...

[WimVriend]

Hello Harry,

OK, I'm looking forward to your findings. A 3rd option is always welcome :)
For now, I'll close this thread.

Thanks for your help!