title: Get bluetooth data from a scale device
body: <p>i am using this plugin : <a href="https://github.com/don/cordova-plugin-ble-central" rel="nofollow noreferrer">https://github.com/don/cordova-plugin-ble-central</a></p>
  
  <p>i can scan bluetooth devices, my scale is detected and i can connect to it
  but i can't get any data from the device.</p>
  
  <p>what is the process to get data from a bluetooth device with that plugin?</p>
  
  <p>here some code error:</p>
  
  <pre><code> W/PluginManager( 5949): THREAD WARNING: exec() call to BLE.stopScan blocked the main thread for 24ms. Plugin should use CordovaInterface.getThreadPool().
  D/BluetoothGatt( 5949): connect() - device: 7C:66:9D:9E:46:31, auto: false
  D/BluetoothGatt( 5949): registerApp()
  D/BluetoothGatt( 5949): registerApp() - UUID=08a761d6-34e9-4db3-8c58-258786ad7c3c
  D/BtGatt.GattService( 2228): registerClient() - UUID=08a761d6-34e9-4db3-8c58-258786ad7c3c
  D/BtGatt.GattService( 2228): onClientRegistered() - UUID=08a761d6-34e9-4db3-8c58-258786ad7c3c, clientIf=5
  D/BluetoothGatt( 5949): onClientRegistered() - status=0 clientIf=5
  D/BtGatt.GattService( 2228): clientConnect() - address=7C:66:9D:9E:46:31, isDirect=true
  D/btif_config( 2228): btif_get_address_type: Device [7c:66:9d:9e:46:31] address type 0
  D/btif_config( 2228): btif_get_device_type: Device [7c:66:9d:9e:46:31] type 2
  D/cr_Ime  ( 5949): [InputMethodManagerWrapper.java:59] isActive: true
  D/cr_Ime  ( 5949): [InputMethodManagerWrapper.java:68] hideSoftInputFromWindow
  E/bt-btm  ( 2228): Random unmatch
  W/bt-btm  ( 2228): btm_acl_created hci_handle=2 link_role=0  transport=2
  W/bt-btif ( 2228): info:x0
  W/bt-l2cap( 2228): L2CA_SetDesireRole() new:x0, disallow_switch:0
  D/        ( 2228): remote version info [7c:66:9d:9e:46:31]: 0, 0, 0
  D/BtGatt.GattService( 2228): onConnected() - clientIf=5, connId=5, address=7C:66:9D:9E:46:31
  D/BluetoothGatt( 5949): onClientConnectionState() - status=0 clientIf=5 device=7C:66:9D:9E:46:31
  D/BluetoothGatt( 5949): discoverServices() - device: 7C:66:9D:9E:46:31
  D/BtGatt.GattService( 2228): discoverServices() - address=7C:66:9D:9E:46:31, connId=5
  E/bt-btif ( 2228): No More Service found
  D/BtGatt.GattService( 2228): onSearchCompleted() - connId=5, status=0
  D/BluetoothGatt( 5949): onSearchComplete() = Device=7C:66:9D:9E:46:31 Status=0
  E/PluginManager( 5949): Uncaught exception from plugin
  E/PluginManager( 5949): java.lang.NumberFormatException: Invalid long: "0000null"
  E/PluginManager( 5949):     at java.lang.Long.invalidLong(Long.java:124)
  E/PluginManager( 5949):     at java.lang.Long.parse(Long.java:363)
  E/PluginManager( 5949):     at java.lang.Long.parsePositiveLong(Long.java:413)
  E/PluginManager( 5949):     at java.util.UUID.fromString(UUID.java:190)
  E/PluginManager( 5949):     at com.megster.cordova.ble.central.UUIDHelper.uuidFromString(UUIDHelper.java:32)
  E/PluginManager( 5949):     at com.megster.cordova.ble.central.BLECentralPlugin.uuidFromString(BLECentralPlugin.java:573)
  E/PluginManager( 5949):     at com.megster.cordova.ble.central.BLECentralPlugin.execute(BLECentralPlugin.java:163)
  E/PluginManager( 5949):     at org.apache.cordova.CordovaPlugin.execute(CordovaPlugin.java:117)
  E/PluginManager( 5949):     at org.apache.cordova.CordovaPlugin.execute(CordovaPlugin.java:98)
  E/PluginManager( 5949):     at org.apache.cordova.PluginManager.exec(PluginManager.java:133)
  E/PluginManager( 5949):     at org.apache.cordova.CordovaBridge.jsExec(CordovaBridge.java:59)
  E/PluginManager( 5949):     at org.apache.cordova.engine.SystemExposedJsApi.exec(SystemExposedJsApi.java:41)
  E/PluginManager( 5949):     at org.chromium.base.SystemMessageHandler.nativeDoRunLoopOnce(Native Method)
  E/PluginManager( 5949):     at org.chromium.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:39)
  E/PluginManager( 5949):     at android.os.Handler.dispatchMessage(Handler.java:102)
  E/PluginManager( 5949):     at android.os.Looper.loop(Looper.java:135)
  E/PluginManager( 5949):     at android.os.HandlerThread.run(HandlerThread.java:61)
  W/cr_BindingManager( 5949): Cannot call determinedVisibility() - never saw a connection for the pid: 5949
  D/HeadsetStateMachine( 2228): Disconnected process message: 10, size: 0
  </code></pre>