Android Bluetooth Low Energy 基礎(chǔ)

1谣辞、關(guān)于Android平臺(tái)的BLE

藍(lán)牙4.0于2010年發(fā)布虱颗，相對(duì)于上個(gè)版本3.0赋访，它的特點(diǎn)是更省電逝淹、成本低 延遲低等特點(diǎn)律罢，現(xiàn)在最新的藍(lán)牙協(xié)議是2013年底發(fā)布的藍(lán)牙4.1膀值，藍(lán)牙4.1在4.0 基礎(chǔ)上進(jìn)行升級(jí)，使得可穿戴設(shè)備的批量數(shù)據(jù)傳輸速度更高误辑。Android是從4.3 才開始提供BLE API,這也就限定了BLE的應(yīng)用只能運(yùn)行在Android 4.3及其以上 的系統(tǒng)沧踏。在Android平臺(tái)上的藍(lán)牙4.0主要有兩種工作模式:經(jīng)典藍(lán)牙(classic bluetooth) 、低功耗藍(lán)牙(bluetooth low energy,縮寫為BLE)

2巾钉、角色與職責(zé)

當(dāng)一個(gè)Android設(shè)備與一個(gè)BLE設(shè)備進(jìn)行交互通信時(shí)翘狱，主要存在以下兩種關(guān)系
中心設(shè)備與外圍設(shè)備：中心設(shè)備扮演掃描的角色，尋找外圍設(shè)備的廣播消息砰苍。Android設(shè)備 作為中心設(shè)備潦匈，與之連接通信的設(shè)備作為外圍設(shè)備。

GATT服務(wù)器與GATT客戶端：這種關(guān)系決定了當(dāng)連接建立后兩個(gè)設(shè)備如何通信赚导。

注：目前Android系統(tǒng)提供的API使得Android設(shè)備只能作為中心設(shè)備

3茬缩、組成部分

BLE分為三個(gè)部分Service、Characteristic吼旧、Descriptor凰锡，每個(gè)部分都擁有不同的 UUID來標(biāo)識(shí)。一個(gè)BLE設(shè)備可以擁有多個(gè)Service，一個(gè)Service可以包含多個(gè)Characteristic掂为， 一個(gè)Characteristic包含一個(gè)Value和多個(gè)Descriptor裕膀，一個(gè)Descriptor包含一個(gè)Value。 通信數(shù)據(jù)一般存儲(chǔ)在Characteristic內(nèi)勇哗，目前一個(gè)Characteristic中存儲(chǔ)的數(shù)據(jù)最大為20 byte昼扛。 與Characteristic相關(guān)的權(quán)限字段主要有READ、WRITE智绸、WRITE_NO_RESPONSE野揪、NOTIFY。 Characteristic具有的權(quán)限屬性可以有一個(gè)或者多個(gè)瞧栗。

4斯稳、核心代碼

private BluetoothAdapter mBtAdapter = null;
private BluetoothGatt mBtGatt = null;
private int mState = 0;
private Context mContext;
private BluetoothGattCharacteristic mWriteCharacteristic = null;
private BluetoothGattCharacteristic mReadCharacteristric = null;
 
private final String TAG = "BLE_Demo";
 
// 設(shè)備連接狀態(tài)
private final int CONNECTED = 0x01;
private final int DISCONNECTED = 0x02;
private final int CONNECTTING = 0x03;
 
// 讀寫相關(guān)的Service、Characteristic的UUID
public static final UUID TRANSFER_SERVICE_READ = UUID.fromString("34567817-2432-5678-1235-3c1d5ab44e17");
public static final UUID TRANSFER_SERVICE_WRITE = UUID.fromString("34567817-2432-5678-1235-3c1d5ab44e18");
public static final UUID TRANSFER_CHARACTERISTIC_READ = UUID.fromString("23487654-5678-1235-2432-3c1d5ab44e94");
public static final UUID TRANSFER_CHARACTERISTIC_WRITE = UUID.fromString("23487654-5678-1235-2432-3c1d5ab44e93");
 
// BLE設(shè)備連接通信過程中回調(diào)
private BluetoothGattCallback mBtGattCallback = new BluetoothGattCallback() {
 
    // 連接狀態(tài)發(fā)生改變時(shí)的回調(diào)
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status,
                int newState) {
 
        if (status == BluetoothGatt.GATT_SUCCESS) {
            mState = CONNECTED;
            Log.d(TAG, "connected OK");
            mBtGatt.discoverServices();
        } else if (newState == BluetoothGatt.GATT_FAILURE) {
            mState = DISCONNECTED;
            Log.d(TAG, "connect failed");
        }
    }
 
    // 遠(yuǎn)端設(shè)備中的服務(wù)可用時(shí)的回調(diào)
    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
 
        if (status == BluetoothGatt.GATT_SUCCESS) {
            BluetoothGattService btGattWriteService = mBtGatt
                    .getService(TRANSFER_SERVICE_WRITE);
            BluetoothGattService btGattReadService = mBtGatt
                    .getService(TRANSFER_SERVICE_READ);
            if (btGattWriteService != null) {
                mWriteCharacteristic = btGattWriteService
                        .getCharacteristic(TRANSFER_CHARACTERISTIC_WRITE);
            }
            if (btGattReadService != null) {
                mReadCharacteristric = btGattReadService
                        .getCharacteristic(TRANSFER_CHARACTERISTIC_READ);
                if (mReadCharacteristric != null) {
                    mBtGatt.readCharacteristic(mReadCharacteristric);
                }
            }
        }
    }
 
    // 某Characteristic的狀態(tài)為可讀時(shí)的回調(diào)
    @Override
    public void onCharacteristicRead(BluetoothGatt gatt,
            BluetoothGattCharacteristic characteristic, int status) {
 
        if (status == BluetoothGatt.GATT_SUCCESS) {
            readCharacterisricValue(characteristic);
 
            // 訂閱遠(yuǎn)端設(shè)備的characteristic迹恐，
            // 當(dāng)此characteristic發(fā)生改變時(shí)當(dāng)回調(diào)mBtGattCallback中的onCharacteristicChanged方法
            mBtGatt.setCharacteristicNotification(mReadCharacteristric,
                    true);
            BluetoothGattDescriptor descriptor = mReadCharacteristric
                    .getDescriptor(UUID
                            .fromString("00002902-0000-1000-8000-00805f9b34fb"));
            if (descriptor != null) {
                byte[] val = BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE;
                descriptor.setValue(val);
                mBtGatt.writeDescriptor(descriptor);
            }
        }
    }
 
    // 寫入Characteristic成功與否的回調(diào)
    @Override
    public void onCharacteristicWrite(BluetoothGatt gatt,
            BluetoothGattCharacteristic characteristic, int status) {
 
        switch (status) {
        case BluetoothGatt.GATT_SUCCESS:
            Log.d(TAG, "write data success");
            break;// 寫入成功
        case BluetoothGatt.GATT_FAILURE:
            Log.d(TAG, "write data failed");
            break;// 寫入失敗
        case BluetoothGatt.GATT_WRITE_NOT_PERMITTED:
            Log.d(TAG, "write not permitted");
            break;// 沒有寫入的權(quán)限
        }
    }
 
    // 訂閱了遠(yuǎn)端設(shè)備的Characteristic信息后挣惰，
    // 當(dāng)遠(yuǎn)端設(shè)備的Characteristic信息發(fā)生改變后,回調(diào)此方法
    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt,
            BluetoothGattCharacteristic characteristic) {
        readCharacterisricValue(characteristic);
    }
 
};
 
/**
 * 讀取BluetoothGattCharacteristic中的數(shù)據(jù)
 * 
 * @param characteristic
 */
private void readCharacterisricValue(
        BluetoothGattCharacteristic characteristic) {
    byte[] data = characteristic.getValue();
    StringBuffer buffer = new StringBuffer("0x");
    int i;
    for (byte b : data) {
        i = b & 0xff;
        buffer.append(Integer.toHexString(i));
    }
    Log.d(TAG, "read data:" + buffer.toString());
}
 
/**
 * 與指定的設(shè)備建立連接
 * 
 * @param device
 */
public void connect(BluetoothDevice device) {
 
    mBtGatt = device.connectGatt(mContext, false, mBtGattCallback);
    mState = CONNECTTING;
}
 
/**
 * 初始化
 * 
 * @param context
 * @return 如果初始化成功則返回true
 */
public boolean init(Context context) {
    BluetoothManager btMrg = (BluetoothManager) context
            .getSystemService(Context.BLUETOOTH_SERVICE);
    if (btMrg == null)
        return false;
    mBtAdapter = btMrg.getAdapter();
    if (mBtAdapter == null)
        return false;
    mContext = context;
    return true;
}
 
// BLE設(shè)備搜索過程中的回調(diào)，在此可以根據(jù)外圍設(shè)備廣播的消息來對(duì)設(shè)備進(jìn)行過濾
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
     
    @Override
    public void onLeScan(final BluetoothDevice device, int rssi,
            byte[] scanRecord) {
         
        ArrayUtils.reverse(scanRecord);// 數(shù)組反轉(zhuǎn)
        // 將Byte數(shù)組的數(shù)據(jù)以十六進(jìn)制表示并拼接成字符串
        StringBuffer str = new StringBuffer();
        int i = 0;
        for (byte b : scanRecord) {
            i = (b & 0xff);
            str.append(Integer.toHexString(i));
        }
        String discoveryServceID = str.toString();
        Log.d(TAG, device.getName() + " scanRecord:\n" + discoveryServceID);
         
        // 查詢是否含有指定的Service UUID信息
        if (discoveryServceID.indexOf(TRANSFER_SERVICE_WRITE.toString()
                .replace("-", "")) != -1) {
 
            Log.d(TAG, device.getName() + " has available service UUID");
 
            // 在這是處理匹配的設(shè)備……
 
        }
 
    }
 
};
 
/**
 * 開始BLE設(shè)備掃描
 */
public void startScan() {
    mBtAdapter.startLeScan(mLeScanCallback);
}
 
/**
 * 停止BLE設(shè)備掃描
 */
public void stopScan() {
    mBtAdapter.stopLeScan(mLeScanCallback);
}
 
/**
 * 發(fā)送數(shù)據(jù)
 * 
 * @param data
 *            待發(fā)送的數(shù)據(jù),最大長(zhǎng)度為20
 */
private void sendData(byte[] data) {
 
    if (data != null && data.length > 0 && data.length < 21) {
        if (mWriteCharacteristic.setValue(data)
                && mBtGatt.writeCharacteristic(mWriteCharacteristic)) {
            Log.d(TAG, "send data OK");
        }
    }
}

Android Bluetooth Low Energy 數(shù)據(jù)的寫入與讀取 第一天

1 殴边、啟動(dòng)ble設(shè)備連接的方法首先要得到一個(gè)BluetoothDevice憎茂， 這個(gè)可以通過，android搜索一配對(duì)或者為配對(duì)的藍(lán)牙設(shè)備獲取得到BluetoothDevice的對(duì)象锤岸，也可以通過搜索ble設(shè)備去得到一個(gè)BluetoothDevice的對(duì)象（下面會(huì)仔細(xì)說索搜ble設(shè)備）需要注意的是竖幔，當(dāng)一個(gè)ble設(shè)備作為一個(gè)藍(lán)牙設(shè)備連接到了android 設(shè)備上的話，我們通過搜索ble設(shè)備的api是搜索不到的是偷。

2拳氢、得到一個(gè)藍(lán)牙已配對(duì)設(shè)備

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mBluetoothAdapter.startDiscovery();
 
Set<BluetoothDevice> bledevices = mBluetoothAdapter.getBondedDevices();
if (bledevices.size() > 0)
{
    for (BluetoothDevice bluetoothDevice : bledevices)
    {
        if (bluetoothDevice.getAddress().toString()
                .equals(BLUETOOTH_DEVICE_MAC))
        {
            Log.v(TAG, "find with old: " + bluetoothDevice.getAddress());
            bluetoothDevice.connectGatt(getActivity(), false,
                    mGattCallback);
        }
    }
}

3、如何索搜ble設(shè)備 ：

使用BluetoothAdapter 的 startLeScan 方法蛋铆， 

startLeScan 的參數(shù)是一個(gè)回調(diào)馋评。

private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback()
{
 
    @Override
    public void onLeScan(final BluetoothDevice device, int rssi,
            byte[] scanRecord)
    {
        Log.v(TAG, "device: " + device);   
    }
};

在這個(gè)回調(diào)里可以索搜到BLE設(shè)備

4、使用索搜到的設(shè)備連接：

當(dāng)我們搜索到設(shè)備的時(shí)候刺啦， 可以使用

device.connectGatt(getActivity(), false, mGattCallback);

進(jìn)行連接留特，其中 mGattCallback 也是個(gè)回調(diào)方法

 private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback()
    {
 
        // 設(shè)備發(fā)生讀操作時(shí)的回調(diào)
        @Override
        public void onCharacteristicRead(BluetoothGatt gatt,
                BluetoothGattCharacteristic characteristic, int status)
        {
            Log.v(TAG, "onCharacteristicRead: " + characteristic.getUuid());
        }
                  
        // 設(shè)備發(fā)生寫操作是的回調(diào)
        @Override
        public void onCharacteristicWrite(BluetoothGatt gatt,
                BluetoothGattCharacteristic characteristic, int status)
        {
            if (BluetoothGatt.GATT_SUCCESS == status)
            {
                Log.v(TAG, "onCharacteristicWrite: " + characteristic.getUuid());
            }
            super.onCharacteristicWrite(gatt, characteristic, status);
        }
 
        // 設(shè)備連接狀態(tài)發(fā)生更改時(shí)的回調(diào)
        // 我們要在這里進(jìn)行discoverServices()
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status,
                int newState)
        {
            gatt.discoverServices();
            super.onConnectionStateChange(gatt, status, newState);
        }
 
        // 當(dāng)BLE設(shè)備中的服務(wù)被找到時(shí)，回調(diào)如下方法
        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status)
        {
            Log.v(TAG, "onServicesDiscovered: " + gatt.getServices().size());
 
            super.onServicesDiscovered(gatt, status);
        }
 
    };

5玛瘸、重點(diǎn)：數(shù)據(jù)的IO
無論數(shù)據(jù)或是寫蜕青，都需要

BluetoothGattService mSVC = gatt.getService(UUID
                    .fromString("0000dfb0-0000-1000-8000-00805f9b34fb"));
BluetoothGattCharacteristic mCH = mSVC.getCharacteristic(UUID
                    .fromString("0000dfb1-0000-1000-8000-00805f9b34fb"));

得到一個(gè)BluetoothGattCharacteristic ， 如上捧韵， 我們同過一個(gè)指定uuid的方式市咆，在

public
void
onServicesDiscovered() 方法中

得到gatt ，調(diào)用gatt的讀操作

gatt.readCharacteristic(mCH);

執(zhí)行這部操作之后再来， 我們會(huì)在 onCharacteristicRead 方法回掉這個(gè) Characteristic 的所帶有的value

寫操作則是

mCH.setValue(GAME_MODE);
gatt.writeCharacteristic(mCH);

同理，在 onCharacteristicWrite 方法中可以獲得操作的提示。

20151120 芒篷， 目前我可以讀到 

Characteristic 里的數(shù)據(jù)搜变，結(jié)果也正確， 但是無法語言寫入是否正確针炉，目前執(zhí)行了write的操作挠他，系統(tǒng)顯示寫入正常， 但是看不到相應(yīng)的變化篡帕，

指環(huán)的模式并沒有變化殖侵。ps：我在提供的demo中執(zhí)行寫操作，指環(huán)的狀態(tài)也為改變（之前改過機(jī)會(huì)镰烧，目前不知道情況）

Android Bluetooth Low Energy 數(shù)據(jù)的寫入與讀取 第二天

1拢军、使用
writeCharacteristic 讀寫數(shù)據(jù)，（順便說一句怔鳖，今天反復(fù)的調(diào)試之后茉唉，公司這邊的藍(lán)牙設(shè)備終于可以切換模式了，不知道為什么之前嘗試的總是不行）结执，今天做下總結(jié)度陆。

2、由于android ble 的接口都是異步的献幔， 所以我們所調(diào)用的方法都要在回掉函數(shù)中進(jìn)行懂傀，寫一個(gè)簡(jiǎn)單的流程圖， 方便理解：(圖畫的不專業(yè)蜡感， 湊合看看)

Paste_Image.png

3蹬蚁、寫數(shù)據(jù)的時(shí)候?qū)⒅颠@樣寫 ch.setValue(new byte[] { (byte) 0x00, (byte) 0xff });

package youten.redo.ble.readwrite;
 
import java.util.Set;
import java.util.UUID;
 
import youten.redo.ble.util.BleUtil;
import youten.redo.ble.util.BleUuid;
import android.app.Activity;
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.bluetooth.BluetoothProfile;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.Toast;
 
public class DeviceActivity extends Activity implements View.OnClickListener
{
    private static final String TAG = "BLEDevice";
 
    public static final String EXTRA_BLUETOOTH_DEVICE = "BT_DEVICE";
    private BluetoothAdapter mBTAdapter;
    private BluetoothDevice mDevice;
    private BluetoothGatt mConnGatt;
    private int mStatus;
 
    private Button mReadManufacturerNameButton;
    private Button mReadSerialNumberButton;
    private Button mWriteAlertLevelButton;
 
    private final BluetoothGattCallback mGattcallback = new BluetoothGattCallback()
    {
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status,
                int newState)
        {
            if (newState == BluetoothProfile.STATE_CONNECTED)
            {
                mStatus = newState;
                Log.v(TAG, "connected and discoverServices");
                mConnGatt.discoverServices();
            } else if (newState == BluetoothProfile.STATE_DISCONNECTED)
            {
                mStatus = newState;
                runOnUiThread(new Runnable()
                {
                    public void run()
                    {
                        mReadManufacturerNameButton.setEnabled(false);
                        mReadSerialNumberButton.setEnabled(false);
                        mWriteAlertLevelButton.setEnabled(false);
                    };
                });
            }
        };
 
        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status)
        {
            Log.v(TAG, "is have services");
            for (BluetoothGattService service : gatt.getServices())
            {
                if ((service == null) || (service.getUuid() == null))
                {
                    continue;
                }
                if (BleUuid.SERVICE_DEVICE_INFORMATION.equalsIgnoreCase(service
                        .getUuid().toString()))
                {
                    mReadManufacturerNameButton
                            .setTag(service.getCharacteristic(UUID
                                    .fromString(BleUuid.CHAR_MANUFACTURER_NAME_STRING)));
                    mReadSerialNumberButton
                            .setTag(service.getCharacteristic(UUID
                                    .fromString(BleUuid.CHAR_SERIAL_NUMBEAR_STRING)));
                    runOnUiThread(new Runnable()
                    {
                        public void run()
                        {
                            mReadManufacturerNameButton.setEnabled(true);
                            mReadSerialNumberButton.setEnabled(true);
                        };
                    });
                }
                if (BleUuid.SERVICE_IMMEDIATE_ALERT.equalsIgnoreCase(service
                        .getUuid().toString()))
                {
                    runOnUiThread(new Runnable()
                    {
                        public void run()
                        {
                            mWriteAlertLevelButton.setEnabled(true);
                        };
                    });
                    mWriteAlertLevelButton.setTag(service
                            .getCharacteristic(UUID
                                    .fromString(BleUuid.CHAR_ALERT_LEVEL)));
                }
            }
 
            runOnUiThread(new Runnable()
            {
                public void run()
                {
                    setProgressBarIndeterminateVisibility(false);
                };
            });
        };
 
        @Override
        public void onCharacteristicRead(BluetoothGatt gatt,
                BluetoothGattCharacteristic characteristic, int status)
        {
            if (status == BluetoothGatt.GATT_SUCCESS)
            {
 
                byte[] bytes = characteristic.getValue();
                for (byte b : bytes)
                {
                    Log.v("", "------characteristic------" + b);
                }
 
                if (BleUuid.CHAR_MANUFACTURER_NAME_STRING
                        .equalsIgnoreCase(characteristic.getUuid().toString()))
                {
                    final String name = characteristic.getStringValue(0);
 
                    runOnUiThread(new Runnable()
                    {
                        public void run()
                        {
                            mReadManufacturerNameButton.setText(name);
                            setProgressBarIndeterminateVisibility(false);
                        };
                    });
                } else if (BleUuid.CHAR_SERIAL_NUMBEAR_STRING
                        .equalsIgnoreCase(characteristic.getUuid().toString()))
                {
                    final String name = characteristic.getStringValue(0);
 
                    runOnUiThread(new Runnable()
                    {
                        public void run()
                        {
                            mReadSerialNumberButton.setText(name);
                            setProgressBarIndeterminateVisibility(false);
                        };
                    });
                }
 
            }
        }
 
        @Override
        public void onCharacteristicWrite(BluetoothGatt gatt,
                BluetoothGattCharacteristic characteristic, int status)
        {
 
            if (BluetoothGatt.GATT_SUCCESS == status)
            {
                Log.v(TAG,
                        "write - characteristic: " + characteristic.getUuid());
                Log.v(TAG, "write - service "
                        + characteristic.getService().getUuid());
            }
 
            // 再讀取一次， 驗(yàn)證一下值是不是對(duì)的
            gatt.readCharacteristic(characteristic);
 
            runOnUiThread(new Runnable()
            {
                public void run()
                {
                    setProgressBarIndeterminateVisibility(false);
                };
            });
        };
    };
 
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.activity_device);
 
        // state
        mStatus = BluetoothProfile.STATE_DISCONNECTED;
        mReadManufacturerNameButton = (Button) findViewById(R.id.read_manufacturer_name_button);
        mReadManufacturerNameButton.setOnClickListener(this);
        mReadSerialNumberButton = (Button) findViewById(R.id.read_serial_number_button);
        mReadSerialNumberButton.setOnClickListener(this);
        mWriteAlertLevelButton = (Button) findViewById(R.id.write_alert_level_button);
        mWriteAlertLevelButton.setOnClickListener(this);
    }
 
    @Override
    protected void onResume()
    {
        super.onResume();
 
        init();
    }
 
    @Override
    protected void onDestroy()
    {
        super.onDestroy();
        if (mConnGatt != null)
        {
            if ((mStatus != BluetoothProfile.STATE_DISCONNECTING)
                    && (mStatus != BluetoothProfile.STATE_DISCONNECTED))
            {
                mConnGatt.disconnect();
            }
            mConnGatt.close();
            mConnGatt = null;
        }
    }
 
    @Override
    public void onClick(View v)
    {
        if (v.getId() == R.id.read_manufacturer_name_button)
        {
            if ((v.getTag() != null)
                    && (v.getTag() instanceof BluetoothGattCharacteristic))
            {
                BluetoothGattCharacteristic ch = (BluetoothGattCharacteristic) v
                        .getTag();
                if (mConnGatt.readCharacteristic(ch))
                {
                    setProgressBarIndeterminateVisibility(true);
                }
            }
        } else if (v.getId() == R.id.read_serial_number_button)
        {
            if ((v.getTag() != null)
                    && (v.getTag() instanceof BluetoothGattCharacteristic))
            {
                BluetoothGattCharacteristic ch = (BluetoothGattCharacteristic) v
                        .getTag();
                if (mConnGatt.readCharacteristic(ch))
                {
                    setProgressBarIndeterminateVisibility(true);
                }
            }
 
        } else if (v.getId() == R.id.write_alert_level_button)
        {
            if ((v.getTag() != null)
                    && (v.getTag() instanceof BluetoothGattCharacteristic))
            {
                BluetoothGattCharacteristic ch = (BluetoothGattCharacteristic) v
                        .getTag();
                ch.setValue(new byte[] { (byte) 0x00, (byte) 0xff });
                if (mConnGatt.writeCharacteristic(ch))
                {
                    Log.v(TAG, "1st wirte had readly");
                    setProgressBarIndeterminateVisibility(true);
                }
            }
        }
    }
 
    private void init()
    {
        // BLE check
        if (!BleUtil.isBLESupported(this))
        {
            Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT)
                    .show();
            finish();
            return;
        }
 
        // BT check
        BluetoothManager manager = BleUtil.getManager(this);
        if (manager != null)
        {
            mBTAdapter = manager.getAdapter();
        }
        if (mBTAdapter == null)
        {
            Toast.makeText(this, R.string.bt_unavailable, Toast.LENGTH_SHORT)
                    .show();
            finish();
            return;
        }
 
        // check BluetoothDevice
        if (mDevice == null)
        {
            mDevice = getBTDeviceExtra();
            if (mDevice == null)
            {
                finish();
                return;
            }
        }
 
        // button disable
        mReadManufacturerNameButton.setEnabled(false);
        mReadSerialNumberButton.setEnabled(false);
        mWriteAlertLevelButton.setEnabled(false);
 
        // connect to Gatt
        if ((mConnGatt == null)
                && (mStatus == BluetoothProfile.STATE_DISCONNECTED))
        {
            Log.v(TAG, "try to connect with connectGatt");
            // try to connect
            mConnGatt = mDevice.connectGatt(this, false, mGattcallback);
            mStatus = BluetoothProfile.STATE_CONNECTING;
        } else
        {
            if (mConnGatt != null)
            {
                // re-connect and re-discover Services
                Log.v(TAG, "try to connect with connect...");
                mConnGatt.connect();
                mConnGatt.discoverServices();
            } else
            {
                Log.e(TAG, "state error");
                finish();
                return;
            }
        }
        setProgressBarIndeterminateVisibility(true);
    }
 
    private BluetoothAdapter mBluetoothAdapter;
     
    // 讀取一個(gè)固定的mac 地址铸敏， 進(jìn)行驗(yàn)證
    private static final String BLUETOOTH_DEVICE_MAC = "D0:06:8E:75:56:16";
 
    private BluetoothDevice getBTDeviceExtra()
    {
        BluetoothDevice bleDevice = null;
        Intent intent = getIntent();
        if (intent == null)
        {
            return null;
        }
 
        Bundle extras = intent.getExtras();
        if (extras == null)
        {
            return null;
        }
 
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        mBluetoothAdapter.startDiscovery();
 
        Set<BluetoothDevice> bledevices = mBluetoothAdapter.getBondedDevices();
        if (bledevices.size() > 0)
        {
            for (BluetoothDevice bluetoothDevice : bledevices)
            {
                Log.v(TAG,
                        "bletoothdevice mac address: "
                                + bluetoothDevice.getAddress());
                if (bluetoothDevice.getAddress().toString()
                        .equals(BLUETOOTH_DEVICE_MAC))
                {
                    bleDevice = bluetoothDevice;
                }
            }
        }
 
        return bleDevice;
    }
 
}