How To Establish Connection And Then Read Characteristics In One Activity?

Currently modifying the sample code and I am encountering an error when try to establish a connection and then read a characteristic in one activity. I am getting BleAlreadyConnect

Solution 1:

The thing is that you are connecting twice. You should rather:

@Overrideprotected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_device);

  // How to listen for connection state changes
  bleDevice.observeConnectionStateChanges()
    .compose(bindUntilEvent(DESTROY))
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(this::onConnectionStateChange);

  connectionObservable = bleDevice.establishConnection(this, true)
    .compose(bindUntilEvent(PAUSE))
    .takeUntil(disconnectTriggerSubject)
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .doOnUnsubscribe(this::clearSubscription)
    .compose(new ConnectionSharingAdapter());

  if (isConnected()) {
      triggerDisconnect();
  } else {
      connectionObservable.subscribe(this::onConnectionReceived, this::onConnectionFailure);
  }
}

private void onConnectionReceived(RxBleConnection connection) { 
  Log.d(TAG, "onConnectionReceived");
  connection
    .flatMap(rxBleConnection -> rxBleConnection.readCharacteristic(uuid))
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(bytes -> {
        Log.d(TAG, "onValueReceived:" + bytes);
    }, this::onReadFailure);
}

Full example is here.