how to establish connection with obd2 from android bluetooth

Question

I need to establish connection with obd2 device from my android app,like torque app.I need to pair it from android phone .

Answer 1

this code will help u in pairing with any bluetooth device , give a try

BluetoothDemo.java

package com.bluetooth;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothClass;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelUuid;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class BluetoothDemo extends Activity {
    /** Called when the activity is first created. */
    ListView listViewPaired;
    ListView listViewDetected;
    ArrayList arrayListpaired;
    Button buttonSearch,buttonOn,buttonDesc,buttonOff;
    ArrayAdapter adapter,detectedAdapter;
    static HandleSeacrh handleSeacrh;
    BluetoothDevice bdDevice;
    BluetoothClass bdClass;
    ArrayList arrayListPairedBluetoothDevices;
    private ButtonClicked clicked;
    ListItemClickedonPaired listItemClickedonPaired;
    BluetoothAdapter bluetoothAdapter = null;
    ArrayList arrayListBluetoothDevices = null;
    ListItemClicked listItemClicked;
    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        listViewDetected = (ListView) findViewById(R.id.listViewDetected);
        listViewPaired = (ListView) findViewById(R.id.listViewPaired);
        buttonSearch = (Button) findViewById(R.id.buttonSearch);
        buttonOn = (Button) findViewById(R.id.buttonOn);
        buttonDesc = (Button) findViewById(R.id.buttonDesc);
        buttonOff = (Button) findViewById(R.id.buttonOff); 
        arrayListpaired = new ArrayList();
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        clicked = new ButtonClicked();
        handleSeacrh = new HandleSeacrh();
        arrayListPairedBluetoothDevices = new ArrayList();
        /*
         * the above declaration is just for getting the paired bluetooth devices;
         * this helps in the removing the bond between paired devices.
         */
        listItemClickedonPaired = new ListItemClickedonPaired();
        arrayListBluetoothDevices = new ArrayList();
        adapter= new ArrayAdapter(BluetoothDemo.this, android.R.layout.simple_list_item_1, arrayListpaired);
        detectedAdapter = new ArrayAdapter(BluetoothDemo.this, android.R.layout.simple_list_item_single_choice);
        listViewDetected.setAdapter(detectedAdapter);
        listItemClicked = new ListItemClicked();
        detectedAdapter.notifyDataSetChanged();
        listViewPaired.setAdapter(adapter);
    }
    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        getPairedDevices();
        buttonOn.setOnClickListener(clicked);
        buttonSearch.setOnClickListener(clicked);
        buttonDesc.setOnClickListener(clicked);
        buttonOff.setOnClickListener(clicked);
        listViewDetected.setOnItemClickListener(listItemClicked);
        listViewPaired.setOnItemClickListener(listItemClickedonPaired);
    }
    private void getPairedDevices() {
        Set pairedDevice = bluetoothAdapter.getBondedDevices();            
        if(pairedDevice.size()>0)
        {
            for(BluetoothDevice device : pairedDevice)
            {
                arrayListpaired.add(device.getName()+"\n"+device.getAddress());
                arrayListPairedBluetoothDevices.add(device);
            }
        }
        adapter.notifyDataSetChanged();
    }
    class ListItemClicked implements OnItemClickListener
    {
        @Override
        public void onItemClick(AdapterView parent, View view, int position, long id) {
            // TODO Auto-generated method stub
            bdDevice = arrayListBluetoothDevices.get(position);
            //bdClass = arrayListBluetoothDevices.get(position);
            Log.i("Log", "The dvice : "+bdDevice.toString());
            /*
             * here below we can do pairing without calling the callthread(), we can directly call the
             * connect(). but for the safer side we must usethe threading object.
             */
            //callThread();
            //connect(bdDevice);
            Boolean isBonded = false;
            try {
                isBonded = createBond(bdDevice);
                if(isBonded)
                {
                    //arrayListpaired.add(bdDevice.getName()+"\n"+bdDevice.getAddress());
                    //adapter.notifyDataSetChanged();
                    getPairedDevices();
                    adapter.notifyDataSetChanged();
                }
            } catch (Exception e) {
                e.printStackTrace(); 
            }//connect(bdDevice);
            Log.i("Log", "The bond is created: "+isBonded);
        }       
    }
    class ListItemClickedonPaired implements OnItemClickListener
    {
        @Override
        public void onItemClick(AdapterView parent, View view, int position,long id) {
            bdDevice = arrayListPairedBluetoothDevices.get(position);
            try {
                Boolean removeBonding = removeBond(bdDevice);
                if(removeBonding)
                {
                    arrayListpaired.remove(position);
                    adapter.notifyDataSetChanged();
                }


                Log.i("Log", "Removed"+removeBonding);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    /*private void callThread() {
        new Thread(){
            public void run() {
                Boolean isBonded = false;
                try {
                    isBonded = createBond(bdDevice);
                    if(isBonded)
                    {
                        arrayListpaired.add(bdDevice.getName()+"\n"+bdDevice.getAddress());
                        adapter.notifyDataSetChanged();
                    }
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace(); 
                }//connect(bdDevice);
                Log.i("Log", "The bond is created: "+isBonded);
            }           
        }.start();
    }*/
    private Boolean connect(BluetoothDevice bdDevice) { 
        Boolean bool = false;
        try {
            Log.i("Log", "service method is called ");
            Class cl = Class.forName("android.bluetooth.BluetoothDevice");
            Class[] par = {};
            Method method = cl.getMethod("createBond", par);
            Object[] args = {};
            bool = (Boolean) method.invoke(bdDevice);//, args);// this invoke creates the detected devices paired.
            //Log.i("Log", "This is: "+bool.booleanValue());
            //Log.i("Log", "devicesss: "+bdDevice.getName());
        } catch (Exception e) {
            Log.i("Log", "Inside catch of serviceFromDevice Method");
            e.printStackTrace();
        }
        return bool.booleanValue();
    };


    public boolean removeBond(BluetoothDevice btDevice)  
    throws Exception  
    {  
        Class btClass = Class.forName("android.bluetooth.BluetoothDevice");
        Method removeBondMethod = btClass.getMethod("removeBond");  
        Boolean returnValue = (Boolean) removeBondMethod.invoke(btDevice);  
        return returnValue.booleanValue();  
    }


    public boolean createBond(BluetoothDevice btDevice)  
    throws Exception  
    { 
        Class class1 = Class.forName("android.bluetooth.BluetoothDevice");
        Method createBondMethod = class1.getMethod("createBond");  
        Boolean returnValue = (Boolean) createBondMethod.invoke(btDevice);  
        return returnValue.booleanValue();  
    }  


    class ButtonClicked implements OnClickListener
    {
        @Override
        public void onClick(View view) {
            switch (view.getId()) {
            case R.id.buttonOn:
                onBluetooth();
                break;
            case R.id.buttonSearch:
                arrayListBluetoothDevices.clear();
                startSearching();
                break;
            case R.id.buttonDesc:
                makeDiscoverable();
                break;
            case R.id.buttonOff:
                offBluetooth();
                break;
            default:
                break;
            }
        }
    }
    private BroadcastReceiver myReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Message msg = Message.obtain();
            String action = intent.getAction();
            if(BluetoothDevice.ACTION_FOUND.equals(action)){
                Toast.makeText(context, "ACTION_FOUND", Toast.LENGTH_SHORT).show();

                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                try
                {
                    //device.getClass().getMethod("setPairingConfirmation", boolean.class).invoke(device, true);
                    //device.getClass().getMethod("cancelPairingUserInput", boolean.class).invoke(device);
                }
                catch (Exception e) {
                    Log.i("Log", "Inside the exception: ");
                    e.printStackTrace();
                }

                if(arrayListBluetoothDevices.size()<1) // this checks if the size of bluetooth device is 0,then add the
                {                                           // device to the arraylist.
                    detectedAdapter.add(device.getName()+"\n"+device.getAddress());
                    arrayListBluetoothDevices.add(device);
                    detectedAdapter.notifyDataSetChanged();
                }
                else
                {
                    boolean flag = true;    // flag to indicate that particular device is already in the arlist or not
                    for(int i = 0; i

Here is the main.xml

Add this permissions to your menifest file.

Hope this will clear all your doubts. it helped me in same case.. answered by Narendra pal here on my question