hola.java

package com.edgarmarcopolo.mybleapp;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.util.Log;

public class MainActivity extends AppCompatActivity implements  BluetoothAdapter.LeScanCallback{

    public static final String TAG = MainActivity.class.getSimpleName();
    BluetoothAdapter bluetoothAdapter;
    RecyclerView recyclerView;
    BLEAdapter bleAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = (RecyclerView) findViewById(R.id.listDevices);

        BluetoothManager bluetoothManager = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
        if(bluetoothManager==null){
            //El dispositivo no tiene bluetooth
            Log.wtf(TAG, "El dispositivo no tiene bluetooth");

        }

        assert bluetoothManager != null;
        bluetoothAdapter = bluetoothManager.getAdapter();

        if(bluetoothAdapter!=null){
            scanLeDevice(true);
        }

        //bleAdapter = new BLEAdapter(this);
        //recyclerView.setAdapter(bleAdapter);


    }

    private void scanLeDevice(final boolean enable){
        if(enable){
            bluetoothAdapter.startLeScan(this);
        }else{
            bluetoothAdapter.stopLeScan(this);
        }
    }

    @Override
    public void onLeScan(BluetoothDevice bluetoothDevice, int i, byte[] bytes) {
        if(bluetoothDevice.getAddress().equals("34:81:F4:06:C1:A2")){
            bluetoothAdapter.stopLeScan(this);
            connectDevice(bluetoothDevice);
        }

        Log.wtf(TAG, bluetoothDevice.getName());
        Log.wtf(TAG, bluetoothDevice.getAddress());


    }

    private void connectDevice(BluetoothDevice device){
        device.createBond();
        device.connectGatt(this, false, new BluetoothGattCallback() {
            @Override
            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                super.onConnectionStateChange(gatt, status, newState);
                if(status == BluetoothGatt.GATT_SUCCESS){
                    if(newState == BluetoothGatt.STATE_CONNECTED){}

                }
            }

            @Override
            public void onServicesDiscovered(BluetoothGatt gatt, int status) {
                super.onServicesDiscovered(gatt, status);
                if(status == BluetoothGatt.GATT_SUCCESS){
                    for(BluetoothGattService service: gatt.getServices()){
                        Log.wtf(TAG, "UUID: "+service.getUuid());
                    }
                }
            }

            @Override
            public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
                super.onCharacteristicRead(gatt, characteristic, status);
            }
        });
    }
}