android 低功耗ble藍芽連線跟標準的藍芽連線還是有很大的不同的。本文低功耗藍芽連線程式碼是在sdk的版本4.3以上才支援。所用的核心程式碼連線也是不一樣的。

1、區別

常規的藍芽連線類是BluetoothSocket

final BluetoothDevice device = mBtAdapter.getRemoteDevice(mstrAddress);
try {
mTransferSocket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
} catch (IOException e1) {
	Log.i("err1:", e1.toString());
	mTransferSocket = null;
}

mTransferSocket.connect();
mInputStream = mTransferSocket.getInputStream();
mOutputStream = mTransferSocket.getOutputStream();
 

2、低功耗藍芽連線類BluetoothGatt，完整的連線程式碼如下

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.southgnss.ble;

import android.annotation.SuppressLint;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;

import java.util.List;
import java.util.UUID;

/**
 * Service for managing connection and data communication with a GATT server hosted on a
 * given Bluetooth LE device.
 */
@SuppressLint("NewApi")
public class BluetoothLeService extends Service {
    private final static String TAG = BluetoothLeService.class.getSimpleName();

    private BluetoothManager mBluetoothManager;
    private BluetoothAdapter mBluetoothAdapter;
    private String mBluetoothDeviceAddress;
    private BluetoothGatt mBluetoothGatt;
    private int mConnectionState = STATE_DISCONNECTED;

    private static final int STATE_DISCONNECTED = 0;
    private static final int STATE_CONNECTING = 1;
    private static final int STATE_CONNECTED = 2;

    public final static String ACTION_GATT_CONNECTED           = "com.example.bluetooth.le.ACTION_GATT_CONNECTED";
    public final static String ACTION_GATT_DISCONNECTED        = "com.example.bluetooth.le.ACTION_GATT_DISCONNECTED";
    public final static String ACTION_GATT_SERVICES_DISCOVERED = "com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED";
    public final static String ACTION_DATA_AVAILABLE           = "com.example.bluetooth.le.ACTION_DATA_AVAILABLE";
    public final static String EXTRA_DATA                      = "com.example.bluetooth.le.EXTRA_DATA";

    public final static UUID UUID_HEART_RATE_MEASUREMENT       = UUID.fromString(SampleGattAttributes.HEART_RATE_MEASUREMENT);

    // Implements callback methods for GATT events that the app cares about.  For example,
    // connection change and services discovered.
    private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
            String intentAction;
            if (newState == BluetoothProfile.STATE_CONNECTED) {
                intentAction = ACTION_GATT_CONNECTED;
                mConnectionState = STATE_CONNECTED;
                broadcastUpdate(intentAction);
                Log.i(TAG, "Connected to GATT server.");
                // Attempts to discover services after successful connection.
                Log.i(TAG, "Attempting to start service discovery:" +
                        mBluetoothGatt.discoverServices());

            } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
                intentAction = ACTION_GATT_DISCONNECTED;
                mConnectionState = STATE_DISCONNECTED;
                Log.i(TAG, "Disconnected from GATT server.");
                broadcastUpdate(intentAction);
            }
        }

        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
            if (status == BluetoothGatt.GATT_SUCCESS) {
                broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
            } else {
                Log.w(TAG, "onServicesDiscovered received: " + status);
            }
        }
        //readCharacteristic的時候會觸發
        @Override
        public void onCharacteristicRead(BluetoothGatt gatt,
                                         BluetoothGattCharacteristic characteristic,
                                         int status) {
            if (status == BluetoothGatt.GATT_SUCCESS) {
                broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
            }
        }
        //需要先開啟notify，設定特徵值發生變化時呼叫此方法
        @Override
        public void onCharacteristicChanged(BluetoothGatt gatt,
                                            BluetoothGattCharacteristic characteristic) {
            broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
        }
    };

    private void broadcastUpdate(final String action) {
        final Intent intent = new Intent(action);
        sendBroadcast(intent);
    }

    private void broadcastUpdate(final String action,
                                 final BluetoothGattCharacteristic characteristic) {
        final Intent intent = new Intent(action);

        // This is special handling for the Heart Rate Measurement profile.  Data parsing is
        // carried out as per profile specifications:
        // http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
        if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
            int flag = characteristic.getProperties();
            int format = -1;
            if ((flag & 0x01) != 0) {
                format = BluetoothGattCharacteristic.FORMAT_UINT16;
                Log.d(TAG, "Heart rate format UINT16.");
            } else {
                format = BluetoothGattCharacteristic.FORMAT_UINT8;
                Log.d(TAG, "Heart rate format UINT8.");
            }
            final int heartRate = characteristic.getIntValue(format, 1);
            Log.d(TAG, String.format("Received heart rate: %d", heartRate));
            intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
            sendBroadcast(intent);
        } else {
            // For all other profiles, writes the data formatted in HEX.
            final byte[] data = characteristic.getValue();
           /* if (data != null && data.length > 0) {
                final StringBuilder stringBuilder = new StringBuilder(data.length);
                for(byte byteChar : data)
                    stringBuilder.append(String.format("%02X ", byteChar));
                intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
            }*/
            if (data[0]=='A') {
            	return;
            }
            else{
            intent.putExtra(EXTRA_DATA, new String(data));
            
            Log.i("yq","data字串："+ new String(data));
            sendBroadcast(intent);
            }
        }
        
    }

    public class LocalBinder extends Binder {
        BluetoothLeService getService() {
            return BluetoothLeService.this;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

    @Override
    public boolean onUnbind(Intent intent) {
        // After using a given device, you should make sure that BluetoothGatt.close() is called
        // such that resources are cleaned up properly.  In this particular example, close() is
        // invoked when the UI is disconnected from the Service.
        close();
        return super.onUnbind(intent);
    }

    private final IBinder mBinder = new LocalBinder();

    /**
     * Initializes a reference to the local Bluetooth adapter.
     *
     * @return Return true if the initialization is successful.
     */
    public boolean initialize() {
        // For API level 18 and above, get a reference to BluetoothAdapter through
        // BluetoothManager.
        if (mBluetoothManager == null) {
            mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            if (mBluetoothManager == null) {
                Log.e(TAG, "Unable to initialize BluetoothManager.");
                return false;
            }
        }

        mBluetoothAdapter = mBluetoothManager.getAdapter();
        if (mBluetoothAdapter == null) {
            Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
            return false;
        }

        return true;
    }

    /**
     * Connects to the GATT server hosted on the Bluetooth LE device.
     *
     * @param address The device address of the destination device.
     *
     * @return Return true if the connection is initiated successfully. The connection result
     *         is reported asynchronously through the
     *         {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
     *         callback.
     */
    public boolean connect(final String address) {
        if (mBluetoothAdapter == null || address == null) {
            Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
            return false;
        }

        // Previously connected device.  Try to reconnect.
        if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
                && mBluetoothGatt != null) {
            Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
            if (mBluetoothGatt.connect()) {
                mConnectionState = STATE_CONNECTING;
                return true;
            } else {
                return false;
            }
        }

        final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        if (device == null) {
            Log.w(TAG, "Device not found.  Unable to connect.");
            return false;
        }
        // We want to directly connect to the device, so we are setting the autoConnect
        // parameter to false.
        mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
        Log.d(TAG, "Trying to create a new connection.");
        mBluetoothDeviceAddress = address;
        mConnectionState = STATE_CONNECTING;
        return true;
    }

    /**
     * Disconnects an existing connection or cancel a pending connection. The disconnection result
     * is reported asynchronously through the
     * {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
     * callback.
     */
    public void disconnect() {
        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
            Log.w(TAG, "BluetoothAdapter not initialized");
            return;
        }
        mBluetoothGatt.disconnect();
    }

    /**
     * After using a given BLE device, the app must call this method to ensure resources are
     * released properly.
     */
    public void close() {
        if (mBluetoothGatt == null) {
            return;
        }
        mBluetoothGatt.close();
        mBluetoothGatt = null;
    }

    /**
     * Request a read on a given {@code BluetoothGattCharacteristic}. The read result is reported
     * asynchronously through the {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
     * callback.
     *
     * @param characteristic The characteristic to read from.
     */
    public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
            Log.w(TAG, "BluetoothAdapter not initialized");
            return;
        }
        mBluetoothGatt.readCharacteristic(characteristic);
    }

    /**
     * Enables or disables notification on a give characteristic.
     *
     * @param characteristic Characteristic to act on.
     * @param enabled If true, enable notification.  False otherwise.
     */
    public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
                                              boolean enabled) {
        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
            Log.w(TAG, "BluetoothAdapter not initialized");
            return;
        }
        mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);

        // This is specific to Heart Rate Measurement.
        if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
            BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
                    UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
            descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
            mBluetoothGatt.writeDescriptor(descriptor);
        }
    }

    /**
     * Retrieves a list of supported GATT services on the connected device. This should be
     * invoked only after {@code BluetoothGatt#discoverServices()} completes successfully.
     *
     * @return A {@code List} of supported services.
     */
    public List<BluetoothGattService> getSupportedGattServices() {
        if (mBluetoothGatt == null) return null;

        return mBluetoothGatt.getServices();
    }
}
 

    private void broadcastUpdate(final String action,
                                 final BluetoothGattCharacteristic characteristic) {
        final Intent intent = new Intent(action);

        // This is special handling for the Heart Rate Measurement profile.  Data parsing is
        // carried out as per profile specifications:
        // http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
        if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
            int flag = characteristic.getProperties();
            int format = -1;
            if ((flag & 0x01) != 0) {
                format = BluetoothGattCharacteristic.FORMAT_UINT16;
                Log.d(TAG, "Heart rate format UINT16.");
            } else {
                format = BluetoothGattCharacteristic.FORMAT_UINT8;
                Log.d(TAG, "Heart rate format UINT8.");
            }
            final int heartRate = characteristic.getIntValue(format, 1);
            Log.d(TAG, String.format("Received heart rate: %d", heartRate));
            intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
            sendBroadcast(intent);
        } else {
            // For all other profiles, writes the data formatted in HEX.
            final byte[] data = characteristic.getValue();
           /* if (data != null && data.length > 0) {
                final StringBuilder stringBuilder = new StringBuilder(data.length);
                for(byte byteChar : data)
                    stringBuilder.append(String.format("%02X ", byteChar));
                intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
            }*/
            if (data[0]=='A') {
            	return;
            }
            else{
            intent.putExtra(EXTRA_DATA, new String(data));
            
            Log.i("yq","data字串："+ new String(data));
            sendBroadcast(intent);
            }
        }
        
    }
 

    // Handles various events fired by the Service.
    // ACTION_GATT_CONNECTED: connected to a GATT server.
    // ACTION_GATT_DISCONNECTED: disconnected from a GATT server.
    // ACTION_GATT_SERVICES_DISCOVERED: discovered GATT services.
    // ACTION_DATA_AVAILABLE: received data from the device.  This can be a result of read
    //                        or notification operations.
    private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) {
                mConnected = true;
                updateConnectionState(true);
            } else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) {
                mConnected = false;
                updateConnectionState(false);
            } else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) {
            	if (mBluetoothLeService.getSupportedGattServices() != null) {
            	List<BluetoothGattCharacteristic> gattCharacteristics = mBluetoothLeService.getSupportedGattServices()
            			.get(mBluetoothLeService.getSupportedGattServices().size()-1).getCharacteristics();
                if (gattCharacteristics != null) {
                    final BluetoothGattCharacteristic characteristic = gattCharacteristics.get(gattCharacteristics.size()-1);
                    final int charaProp = characteristic.getProperties();
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
                        if (mNotifyCharacteristic != null) {
                            mBluetoothLeService.setCharacteristicNotification(
                                    mNotifyCharacteristic, true);
                            mNotifyCharacteristic = null;
                        }
                        mBluetoothLeService.readCharacteristic(characteristic);
                    }
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
                        mNotifyCharacteristic = characteristic;
                        mBluetoothLeService.setCharacteristicNotification(
                                characteristic, true);
                    }
                }					
				}
            } else if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action)) {
                displayData(intent.getStringExtra(BluetoothLeService.EXTRA_DATA));
            }
        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
        if (mBluetoothLeService != null && !mDeviceAddress.isEmpty()) {
            mBluetoothLeService.connect(mDeviceAddress);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mGattUpdateReceiver);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mBluetoothLeService != null) {
            unbindService(mServiceConnection);
            mBluetoothLeService = null;
		}
    }

3、完整的連線類的UI邏輯程式碼

package com.southgnss.ble;

import java.util.List;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothGattCharacteristic;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.southgnss.customwidget.CustomActivity;
import com.southgnss.southgnssserver.R;

public class SouthOtherConnectActivity extends CustomActivity
implements OnClickListener{
    private BluetoothLeService mBluetoothLeService;
    private String mDeviceName = "";
    private String mDeviceAddress = "";
    private boolean mConnected = false;
	private Button mBtnConnect = null;
	private Button mBtnDisConnect = null;
	private TextView mTextViewBlueSelect = null;
    private BluetoothGattCharacteristic mNotifyCharacteristic;
    private View mLinearLayoutEquipmenList;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		getActionBar().setTitle(R.string.sysytem_type_ble_Blue_connect);
		getActionBar().setDisplayHomeAsUpEnabled(true);
		setContentView(R.layout.layout_main_other_connect);
		initView();
			
	}

	private void initView() {
		mLinearLayoutEquipmenList = findViewById(R.id.linearLayoutEquipmenList);
		mLinearLayoutEquipmenList.setOnClickListener(this);
		mTextViewBlueSelect = (TextView)findViewById(R.id.textViewBlueSelect);
		if (!mDeviceName.isEmpty()) mTextViewBlueSelect.setText(mDeviceName);
		if (mDeviceName.isEmpty() && !mDeviceAddress.isEmpty()) mTextViewBlueSelect.setText(mDeviceAddress);
		//連線按鈕
		mBtnConnect = (Button)findViewById(R.id.buttonConnect);
		if(mBtnConnect != null){
			mBtnConnect.setOnClickListener(this);
			mBtnConnect.setEnabled(false);//預設為不可使用
			mBtnConnect.setVisibility(View.VISIBLE);
		}
		mBtnDisConnect  = (Button)findViewById(R.id.buttonDisConnect);
		mBtnDisConnect.setOnClickListener(this);
		mBtnDisConnect.setVisibility(View.GONE);
	}
	
	private boolean getBluetoothDivice() {
		BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
		if (adapter == null) {
			// 不支援藍芽
			return false;
		} 
		
		if (adapter.isEnabled() == false) {
			Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);  
		    // 設定藍芽可見性，最多300秒  
		    intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);  
		    startActivity(intent); 
		    return true;
		}
		 return true;
	}

	@Override
	public void onClick(View arg0) {
		switch (arg0.getId()) {
		case R.id.linearLayoutEquipmenList:
	        // 檢查當前手機是否支援ble 藍芽,如果不支援退出程式
	        if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)
	        		&& android.os.Build.VERSION.SDK_INT > 17) {
	        	ShowTipsInfo(getString(R.string.sysytem_type_ble_Blue_tip));
	           return;
	        }
	        
	        if (!getBluetoothDivice()) {
	        	ShowTipsInfo(getString(R.string.sysytem_type_open_Blue));
	        	return;
			}
			
			Intent newIntent = new Intent(this, BLESearchConnectActivity.class);
			startActivityForResult(newIntent, 1000);
			break;
		case R.id.buttonConnect:
			if (!mConnected && mBluetoothLeService != null && !mDeviceAddress.isEmpty()) {
			    mBluetoothLeService.connect(mDeviceAddress);
			}
			break;
		case R.id.buttonDisConnect:
			if (mConnected && mBluetoothLeService != null) {
				 mBluetoothLeService.disconnect();
				 displayButton(false);
			}
			break;
		default:
			break;
		}
	}
	
	// activity的資料的互動
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		if (data == null || resultCode != RESULT_OK) return;
		switch (requestCode) {
		case 1000: //ble藍芽搜尋返回
			mDeviceName = data.getExtras().getString(BLESearchConnectActivity.EXTRAS_DEVICE_NAME,"");
			mDeviceAddress = data.getExtras().getString(BLESearchConnectActivity.EXTRAS_DEVICE_ADDRESS);
			if (!mDeviceName.isEmpty()) mTextViewBlueSelect.setText(mDeviceName);
			if (mDeviceName.isEmpty() && !mDeviceAddress.isEmpty()) mTextViewBlueSelect.setText(mDeviceAddress);
			mBtnConnect.setEnabled(true);
	        Intent gattServiceIntent = new Intent(this, BluetoothLeService.class);
	        bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);
			break;
		default:
			break;
		}
	}
	
    // Code to manage Service lifecycle.
    private final ServiceConnection mServiceConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName componentName, IBinder service) {
            mBluetoothLeService = ((BluetoothLeService.LocalBinder) service).getService();
            if (!mBluetoothLeService.initialize()) {
                finish();
            }
            mBluetoothLeService.connect(mDeviceAddress);
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            mBluetoothLeService = null;
        }
    };
    
    // Handles various events fired by the Service.
    // ACTION_GATT_CONNECTED: connected to a GATT server.
    // ACTION_GATT_DISCONNECTED: disconnected from a GATT server.
    // ACTION_GATT_SERVICES_DISCOVERED: discovered GATT services.
    // ACTION_DATA_AVAILABLE: received data from the device.  This can be a result of read
    //                        or notification operations.
    private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) {
                mConnected = true;
                updateConnectionState(true);
            } else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) {
                mConnected = false;
                updateConnectionState(false);
            } else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) {
            	if (mBluetoothLeService.getSupportedGattServices() != null) {
            	List<BluetoothGattCharacteristic> gattCharacteristics = mBluetoothLeService.getSupportedGattServices()
            			.get(mBluetoothLeService.getSupportedGattServices().size()-1).getCharacteristics();
                if (gattCharacteristics != null) {
                    final BluetoothGattCharacteristic characteristic = gattCharacteristics.get(gattCharacteristics.size()-1);
                    final int charaProp = characteristic.getProperties();
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
                        if (mNotifyCharacteristic != null) {
                            mBluetoothLeService.setCharacteristicNotification(
                                    mNotifyCharacteristic, true);
                            mNotifyCharacteristic = null;
                        }
                        mBluetoothLeService.readCharacteristic(characteristic);
                    }
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
                        mNotifyCharacteristic = characteristic;
                        mBluetoothLeService.setCharacteristicNotification(
                                characteristic, true);
                    }
                }					
				}
            } else if (BluetoothLeService.ACTION_DATA_AVAILABLE.equals(action)) {
                displayData(intent.getStringExtra(BluetoothLeService.EXTRA_DATA));
            }
        }
    };
    
    private void displayData(String data) {
        if (data != null) {
        	Log.i("Show", data);
        	TextView textViewShow = (TextView)findViewById(R.id.textViewShow);
        	if(textViewShow != null)textViewShow.setText(data);
        }
    }
    
    private void updateConnectionState(final boolean bConnect) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
            	displayButton(bConnect);
            }
        });
    }
    
    private void displayButton(boolean bConnect){
		if (mBtnDisConnect == null || mBtnConnect == null) return;
		if (bConnect) {
			mBtnConnect.setVisibility(View.GONE);
			mBtnDisConnect.setVisibility(View.VISIBLE);
			mLinearLayoutEquipmenList.setEnabled(false);
		} else {
			mBtnDisConnect.setVisibility(View.GONE);
			mBtnConnect.setVisibility(View.VISIBLE);
			mLinearLayoutEquipmenList.setEnabled(true);
		}
    }
    
    private static IntentFilter makeGattUpdateIntentFilter() {
        final IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_CONNECTED);
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_DISCONNECTED);
        intentFilter.addAction(BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED);
        intentFilter.addAction(BluetoothLeService.ACTION_DATA_AVAILABLE);
        return intentFilter;
    }
    
    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mGattUpdateReceiver, makeGattUpdateIntentFilter());
        if (mBluetoothLeService != null && !mDeviceAddress.isEmpty()) {
            mBluetoothLeService.connect(mDeviceAddress);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mGattUpdateReceiver);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mBluetoothLeService != null) {
            unbindService(mServiceConnection);
            mBluetoothLeService = null;
		}
    }
    
}

整個demo的完整程式碼：