java - Android: Bluetooth fails to connect ocasionally -

i have encountered problem when connecting android tablet (5.0.1) bluetooth chip module. problem tablet not connect, yet bluetooth module says connected.

my code is:

private uuid uuid = uuid.fromstring("00001101-0000-1000-8000-00805f9b34fb"); public synchronized void run() {     try {         mysocket = btdevice.createinsecurerfcommsockettoservicerecord(uuid);      } catch (ioexception createsocketexception) {         // problem creating socket         log.e(excp_log, "exception", createsocketexception);     }     // cancel discovery on bluetooth adapter prevent slow connection     btadapter.canceldiscovery();       try {         log.d("bluetooth_debug", "attempting connect");         mysocket.connect();         isconnected = true;      } catch (ioexception connectexception) {         log.d("bluetooth_debug", "connect thread exception");         connectexception.printstacktrace();      }     mhandler.obtainmessage(connected).sendtotarget();  } 

and logcat print out is:

w/bluetoothsocket: readall() looping, read partial size: 11, expect size: 16 w/system.err: java.io.ioexception: connection failure, wrong signal size: 7 w/system.err:     @ android.bluetooth.bluetoothsocket.waitsocketsignal(bluetoothsocket.java:503) w/system.err:     @ android.bluetooth.bluetoothsocket.connect(bluetoothsocket.java:327) w/system.err:     @ bluetoothpackage.connecttobluetooth.run(connecttobluetooth.java:72) w/system.err:     @ java.lang.thread.run(thread.java:818) 

where connecttobluetooth.java code above , line 72 mysocket.connect() command.

any on appreciated