Android : I made an Android app to send string to Arduino via bluetooth but after testing nothing happen

I made an Android app to send string to Arduino via bluetooth but after test nothing happen. I just sent "T" to Arduino. What 's wrong?

Android code:

package app.teststring.app;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.roommanage.app.R;

import app.akexorcist.bluetoothspp.BluetoothSPP;
import app.akexorcist.bluetoothspp.BluetoothSPP.BluetoothConnectionListener;
import app.akexorcist.bluetoothspp.BluetoothSPP.OnDataReceivedListener;
import app.akexorcist.bluetoothspp.BluetoothState;
import app.akexorcist.bluetoothspp.DeviceList;

public class MainActivity extends ActionBarActivity {
    BluetoothSPP bt;
    BluetoothAdapter mBluetoothAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bt = new BluetoothSPP(this);

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

    bt.setOnDataReceivedListener(new OnDataReceivedListener() {
        public void onDataReceived(byte[] data, String message) {
            Toast.makeText(getApplicationContext(), message
                    , Toast.LENGTH_SHORT).show();
        }
    });

    bt.setBluetoothConnectionListener(new BluetoothConnectionListener() {
        public void onDeviceConnected(String name, String address) {
            Toast.makeText(getApplicationContext()
                    , "Connected to " + name + "\n" + address
                    , Toast.LENGTH_SHORT).show();
        }

        public void onDeviceDisconnected() {
            Toast.makeText(getApplicationContext()
                    , "Connection lost", Toast.LENGTH_SHORT).show();
        }

        public void onDeviceConnectionFailed() {
            Toast.makeText(getApplicationContext()
                    , "Unable to connect", Toast.LENGTH_SHORT).show();
        }
    });

    Button btnConnect = (Button)findViewById(R.id.btnConnect);
    btnConnect.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v){
            if(bt.getServiceState() == BluetoothState.STATE_CONNECTED) {
                bt.disconnect();// แก้จาก bt.disconnected()
            } else {
                Intent intent = new Intent(getApplicationContext()
                        , DeviceList.class);
                startActivityForResult(intent
                        , BluetoothState.REQUEST_CONNECT_DEVICE);
            }
        }
    });
}

public void onDestroy() {
    super.onDestroy();
    bt.stopService();
}

public void onStart() {
    super.onStart();
    if (!bt.isBluetoothEnabled()) {
        Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(intent, BluetoothState.REQUEST_ENABLE_BT);
    } else {
        if (!bt.isServiceAvailable()) {
            bt.setupService();
            bt.startService(BluetoothState.DEVICE_OTHER);
            setup();
        }
    }
 }

public void setup() {
    Button btnSubmit = (Button)findViewById(R.id.btnSubmit);
    btnSubmit.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
           bt.send("T");
        }
    });
    bt.autoConnect("HC-05");
}

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(requestCode == BluetoothState.REQUEST_CONNECT_DEVICE) {
        if(resultCode == Activity.RESULT_OK)
            bt.connect(data);
    } else if(requestCode == BluetoothState.REQUEST_ENABLE_BT) {
        if(resultCode == Activity.RESULT_OK) {
            bt.setupService();
            bt.startService(BluetoothState.DEVICE_OTHER);
            setup();
        } else {
            Toast.makeText(getApplicationContext() ,
                    "Bluetooth was not enabled."
                    , Toast.LENGTH_SHORT).show();
            finish();
        }
    }
}

}

Arduino code:

#include <SoftwareSerial.h>

int bluetoothTx = 2;
int bluetoothRx = 3;

SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

String inputString = "";         // a string to hold incoming data
boolean stringComplete = false;  // whether the string is complete

void setup()
{
  pinMode(bluetoothTx,INPUT);
  pinMode(bluetoothRx,OUTPUT);

  //Setup usb serial connection to computer
  Serial.begin(9600);// Begin the serial monitor at 9600bps

  //Setup Bluetooth serial connection to android
  bluetooth.begin(115200);// The Bluetooth Mate defaults to 115200bps
  bluetooth.print("$$$"); // Print three times individually 
  delay(100);// Short delay, wait for the Mate to send back CMD
  bluetooth.println("U,9600,N");// Temporarily Change the baudrate to 9600, no parity
  // 115200 can be too fast at times for NewSoftSerial to relay the data reliably
  bluetooth.begin(9600);// Start bluetooth serial at 9600

  inputString.reserve(200);
}

void loop()
{ 
  // print the string when a newline arrives:
  if (stringComplete) {
    Serial.println(inputString); 
    // clear the string:
    inputString = "";
    stringComplete = false;
  }  
} 

void serialEvent() {
//  while (Serial.available()) {
  while (bluetooth.available()) {
    // get the new byte:    
    char inChar = (char)bluetooth.read(); 
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if ((inChar == '\r') ||(inChar == '\n')) {
      stringComplete = true;
    } 
  }
}

I've changed to Newline in Serial Monitor.