Android Send/Receive data with Arduino using Bluetooth – Part 2

import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
 
public class DeviceListActivity extends Activity {
    // Debugging for LOGCAT
    private static final String TAG = "DeviceListActivity";
    private static final boolean D = true;
 
    // declare button for launching website and textview for connection status
    Button tlbutton;
    TextView textView1;
 
    // EXTRA string to send on to mainactivity
    public static String EXTRA_DEVICE_ADDRESS = "device_address";
 
    // Member fields
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter<String> mPairedDevicesArrayAdapter;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.device_list);
    }
 
    @Override
    public void onResume()
    {
        super.onResume();
        //***************
        checkBTState();
 
        textView1 = (TextView) findViewById(R.id.connecting);
        textView1.setTextSize(40);
        textView1.setText(" ");
 
        // Initialize array adapter for paired devices
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
 
        // Find and set up the ListView for paired devices
        ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
        pairedListView.setAdapter(mPairedDevicesArrayAdapter);
        pairedListView.setOnItemClickListener(mDeviceClickListener);
 
        // Get the local Bluetooth adapter
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();
 
        // Get a set of currently paired devices and append to 'pairedDevices'
        Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
 
        // Add previosuly paired devices to the array
        if (pairedDevices.size() > 0) {
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);//make title viewable
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String noDevices = getResources().getText(R.string.none_paired).toString();
            mPairedDevicesArrayAdapter.add(noDevices);
        }
  }
 
    // Set up on-click listener for the list (nicked this - unsure)
    private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
 
            textView1.setText("Connecting...");
            // Get the device MAC address, which is the last 17 chars in the View
            String info = ((TextView) v).getText().toString();
            String address = info.substring(info.length() - 17);
 
            // Make an intent to start next activity while taking an extra which is the MAC address.
            Intent i = new Intent(DeviceListActivity.this, MainActivity.class);
            i.putExtra(EXTRA_DEVICE_ADDRESS, address);
            startActivity(i);
        }
    };
 
    private void checkBTState() {
        // Check device has Bluetooth and that it is turned on
         mBtAdapter=BluetoothAdapter.getDefaultAdapter(); // CHECK THIS OUT THAT IT WORKS!!!
        if(mBtAdapter==null) {
            Toast.makeText(getBaseContext(), "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
        } else {
          if (mBtAdapter.isEnabled()) {
            Log.d(TAG, "...Bluetooth ON...");
          } else {
            //Prompt user to turn on Bluetooth
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, 1);
 
            }
          }
        }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.arduinosensors"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.arduinosensors.MainActivity"
android:label="@string/app_name"
android:screenOrientation="portrait" >

</activity>
<activity
android:name="com.example.arduinosensors.DeviceListActivity"
android:label="@string/app_name"
android:screenOrientation="portrait" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >

<TextView
android:id="@+id/testView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/txtString"
android:text=""
android:textSize="15sp" />

<TextView
android:id="@+id/txtString"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_alignLeft="@+id/testView1"
android:layout_alignParentBottom="true"
android:text=""
android:textSize="15sp" />

<Button
android:id="@+id/buttonOn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="LED ON" />

<Button
android:id="@+id/buttonOff"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/buttonOn"
android:layout_alignParentRight="true"
android:text="LED OFF" />

<TextView
android:id="@+id/sensorView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/sensorView0"
android:layout_centerHorizontal="true"
android:text="Sensor 1 Voltage = ????"
android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView
android:id="@+id/sensorView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/sensorView1"
android:layout_centerHorizontal="true"
android:text="Sensor 2 Voltage = ????"
android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView
android:id="@+id/sensorView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/sensorView2"
android:layout_centerHorizontal="true"
android:text="Sensor 3 Voltage = ????"
android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView
android:id="@+id/sensorView0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="196dp"
android:text="Sensor 0 Voltage = ????"
android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

package com.example.arduinosensors;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
 
public class MainActivity extends Activity {
 
  Button btnOn, btnOff;
  TextView txtArduino, txtString, txtStringLength, sensorView0, sensorView1, sensorView2, sensorView3;
  Handler bluetoothIn;
 
  final int handlerState = 0;                        //used to identify handler message
  private BluetoothAdapter btAdapter = null;
  private BluetoothSocket btSocket = null;
  private StringBuilder recDataString = new StringBuilder();
 
  private ConnectedThread mConnectedThread;
 
  // SPP UUID service - this should work for most devices
  private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
 
  // String for MAC address
  private static String address;
 
@Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
 
    setContentView(R.layout.activity_main);
 
    //Link the buttons and textViews to respective views
    btnOn = (Button) findViewById(R.id.buttonOn);
    btnOff = (Button) findViewById(R.id.buttonOff);
    txtString = (TextView) findViewById(R.id.txtString);
    txtStringLength = (TextView) findViewById(R.id.testView1);
    sensorView0 = (TextView) findViewById(R.id.sensorView0);
    sensorView1 = (TextView) findViewById(R.id.sensorView1);
    sensorView2 = (TextView) findViewById(R.id.sensorView2);
    sensorView3 = (TextView) findViewById(R.id.sensorView3); 
 
    bluetoothIn = new Handler() {
        public void handleMessage(android.os.Message msg) {
            if (msg.what == handlerState) {                                     //if message is what we want
                String readMessage = (String) msg.obj;                                                                // msg.arg1 = bytes from connect thread
                recDataString.append(readMessage);                                      //keep appending to string until ~
                int endOfLineIndex = recDataString.indexOf("~");                    // determine the end-of-line
                if (endOfLineIndex > 0) {                                           // make sure there data before ~
                    String dataInPrint = recDataString.substring(0, endOfLineIndex);    // extract string
                    txtString.setText("Data Received = " + dataInPrint);
                    int dataLength = dataInPrint.length();                          //get length of data received
                    txtStringLength.setText("String Length = " + String.valueOf(dataLength));
 
                    if (recDataString.charAt(0) == '#')                             //if it starts with # we know it is what we are looking for
                    {
                        String sensor0 = recDataString.substring(1, 5);             //get sensor value from string between indices 1-5
                        String sensor1 = recDataString.substring(6, 10);            //same again...
                        String sensor2 = recDataString.substring(11, 15);
                        String sensor3 = recDataString.substring(16, 20);
 
                        sensorView0.setText(" Sensor 0 Voltage = " + sensor0 + "V");    //update the textviews with sensor values
                        sensorView1.setText(" Sensor 1 Voltage = " + sensor1 + "V");
                        sensorView2.setText(" Sensor 2 Voltage = " + sensor2 + "V");
                        sensorView3.setText(" Sensor 3 Voltage = " + sensor3 + "V");
                    }
                    recDataString.delete(0, recDataString.length());                    //clear all string data
                   // strIncom =" ";
                    dataInPrint = " ";
                }
            }
        }
    };
 
    btAdapter = BluetoothAdapter.getDefaultAdapter();       // get Bluetooth adapter
    checkBTState(); 
 
  // Set up onClick listeners for buttons to send 1 or 0 to turn on/off LED
    btnOff.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        mConnectedThread.write("0");    // Send "0" via Bluetooth
        Toast.makeText(getBaseContext(), "Turn off LED", Toast.LENGTH_SHORT).show();
      }
    });
 
    btnOn.setOnClickListener(new OnClickListener() {
      public void onClick(View v) {
        mConnectedThread.write("1");    // Send "1" via Bluetooth
        Toast.makeText(getBaseContext(), "Turn on LED", Toast.LENGTH_SHORT).show();
      }
    });
  }
 
  private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
 
      return  device.createRfcommSocketToServiceRecord(BTMODULEUUID);
      //creates secure outgoing connecetion with BT device using UUID
  }
 
  @Override
  public void onResume() {
    super.onResume();
 
    //Get MAC address from DeviceListActivity via intent
    Intent intent = getIntent();
 
    //Get the MAC address from the DeviceListActivty via EXTRA
    address = intent.getStringExtra(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
 
    //create device and set the MAC address
    BluetoothDevice device = btAdapter.getRemoteDevice(address);
 
    try {
        btSocket = createBluetoothSocket(device);
    } catch (IOException e) {
        Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_LONG).show();
    }
    // Establish the Bluetooth socket connection.
    try
    {
      btSocket.connect();
    } catch (IOException e) {
      try
      {
        btSocket.close();
      } catch (IOException e2)
      {
        //insert code to deal with this
      }
    }
    mConnectedThread = new ConnectedThread(btSocket);
    mConnectedThread.start();
 
    //I send a character when resuming.beginning transmission to check device is connected
    //If it is not an exception will be thrown in the write method and finish() will be called
    mConnectedThread.write("x");
  }
 
  @Override
  public void onPause()
  {
    super.onPause();
    try
    {
    //Don't leave Bluetooth sockets open when leaving activity
      btSocket.close();
    } catch (IOException e2) {
        //insert code to deal with this
    }
  }
 
 //Checks that the Android device Bluetooth is available and prompts to be turned on if off
  private void checkBTState() {
 
    if(btAdapter==null) {
        Toast.makeText(getBaseContext(), "Device does not support bluetooth", Toast.LENGTH_LONG).show();
    } else {
      if (btAdapter.isEnabled()) {
      } else {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, 1);
      }
    }
  }
 
  //create new class for connect thread
  private class ConnectedThread extends Thread {
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;
 
        //creation of the connect thread
        public ConnectedThread(BluetoothSocket socket) {
            InputStream tmpIn = null;
            OutputStream tmpOut = null;
 
            try {
                //Create I/O streams for connection
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) { }
 
            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }
 
        public void run() {
            byte[] buffer = new byte[256];
            int bytes; 
 
            // Keep looping to listen for received messages
            while (true) {
                try {
                    bytes = mmInStream.read(buffer);            //read bytes from input buffer
                    String readMessage = new String(buffer, 0, bytes);
                    // Send the obtained bytes to the UI Activity via handler
                    bluetoothIn.obtainMessage(handlerState, bytes, -1, readMessage).sendToTarget();
                } catch (IOException e) {
                    break;
                }
            }
        }
        //write method
        public void write(String input) {
            byte[] msgBuffer = input.getBytes();           //converts entered String into bytes
            try {
                mmOutStream.write(msgBuffer);                //write bytes over BT connection via outstream
            } catch (IOException e) {
                //if you cannot write, close the application
                Toast.makeText(getBaseContext(), "Connection Failure", Toast.LENGTH_LONG).show();
                finish();
 
              }
            }
        }
}