NullPointerException for byte[] when sending over bluetooth in android

Question

Why am I getting a NullPointerException when trying to send a byte[] over bluetooth? It happens when mConnectedThread.write(mOutput); is called in the main class near the bottom, right before the inner ConnectThread class. I've been writing logs to the console and they all say the byte isn't null, but it still refuses to be sent. Here's my main class:

public class bluetoothMusicListener extends AppCompatActivity {

BluetoothAdapter mBluetoothAdapter;
Context          mContext;
ConnectedThread  mConnectedThread;
ConnectThread    mConnectThread;
Handler          mHandler;
View             mConnectToDevices;
View             mSendText;
BluetoothDevice  mDevice;
ParcelUuid       list[];

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.bluetooth_listener);

    mConnectToDevices = findViewById(R.id.connectToDevices);
    mSendText = findViewById(R.id.sendText);

    mContext = getApplicationContext();

    mBluetoothAdapter = mBluetoothAdapter.getDefaultAdapter();
    if (mBluetoothAdapter == null) {
        Toast.makeText(mContext, "No bluetooth adapter found", Toast.LENGTH_SHORT).show();
    }

    if (!mBluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, 1);
    }

    mConnectToDevices.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
            //BluetoothDevice mDevice[] = (BluetoothDevice)pairedDevices.toArray();

            if (pairedDevices.size() > 0) {
                for (BluetoothDevice device : pairedDevices) {
                    mDevice = device;
                    list = device.getUuids();
                }
            }

            mHandler = new Handler() {
                @Override
                public void handleMessage(Message msg) {
                    byte[] writeBuf = (byte[]) msg.obj;
                    int begin = (int)msg.arg1;
                    int end = (int)msg.arg2;

                    switch(msg.what) {
                        case 1:
                            String writeMessage = new String(writeBuf);
                            TextView fromDevice = (TextView) findViewById(R.id.fromDevice);
                            fromDevice.setText(writeMessage);
                            break;
                    }
                }
            };

            mConnectThread = new ConnectThread(mDevice, mHandler);
            mConnectThread.start();
        }
    });

    mSendText.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            EditText input = (EditText)findViewById(R.id.editText);

            if (input.getText() != null) {
                //for(int i = 0; i < mConnectedThread.length || i < 5; i++) {
                    String stringOutput = input.getText().toString();
                    byte[] mOutput = (byte[])stringOutput.getBytes();
                    Log.v("input", "input is: " + input);
                    Log.v("input", "input getText is: " + input.getText());
                    Log.v("input", "input getText toString is: " + input.getText().toString());
                    Log.v("input", "output is: " + mOutput.toString());
                    mConnectedThread.write(mOutput);
                //}
            }
        }
    });
}
private class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;
    private final Handler mHandler;
    private final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");

    public ConnectThread(BluetoothDevice device, Handler handler) {
        BluetoothSocket tmp = null;
        mHandler = handler;
        mmDevice = device;
        try {
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) {
            e.printStackTrace();
        }
        mmSocket = tmp;
    }

    public void run() {
        mBluetoothAdapter.cancelDiscovery();
        try {
            mmSocket.connect();
        } catch (IOException connectException) {
            try {
                mmSocket.close();
            } catch (IOException closeException) {
                closeException.printStackTrace();
            }
            return;
        }

        mConnectedThread = new ConnectedThread(mmSocket, mHandler);
        mConnectedThread.start();
    }

    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
}

and here is my ConnectedThread class:

class ConnectedThread extends Thread {
private       BluetoothSocket mmSocket;
private       Handler         mHandler;
private       InputStream     mmInStream;
private       OutputStream    mmOutStream;

public ConnectedThread(BluetoothSocket socket, Handler handler) {
    mmSocket = socket;
    mHandler = handler;
    InputStream tmpIn = null;
    OutputStream tmpOut = null;
    try {
        tmpIn = socket.getInputStream();
        tmpOut = socket.getOutputStream();
    } catch (IOException e) {
        e.printStackTrace();
    }
    mmInStream = tmpIn;
    mmOutStream = tmpOut;
}

public void run() {
    byte[] buffer = new byte[1024];
    int begin = 0;
    int bytes = 0;
    while (true) {
        try {
            bytes += mmInStream.read(buffer, bytes, buffer.length - bytes);
            for(int i = begin; i < bytes; i++) {
                if(buffer[i] == "#".getBytes()[0]) {
                    mHandler.obtainMessage(1, begin, i, buffer).sendToTarget();
                    begin = i + 1;
                    if(i == bytes - 1) {
                        bytes = 0;
                        begin = 0;
                    }
                }
            }
        } catch (IOException e) {
            break;
        }
    }
}

public void write(byte[] bytes) {
    try {
        mmOutStream.write(bytes);
    } catch(IOException e ){
        e.printStackTrace();
    }
}

public void cancel() {
    try {
        mmSocket.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
}

Thank you!