分享Android 藍芽4.0(ble)開發的解決方案_Android

最近，隨著智能穿戴式裝置、智能醫學以及智能家居的普及，藍芽開發在移動開中顯得非常的重要。由於公司需要，研究了一下，藍芽4.0在Android中的應用。

以下是我的一些總結。

1.先介紹一下關於藍芽4.0中的一些名詞吧：   
(1)、GATT(Gneric Attibute  Profile)

通過ble串連，讀寫屬性類小資料Profile通用的規範。現在所有的ble應用Profile  都是基於GATT
(2)、ATT(Attribute Protocal)
GATT是基於ATT Potocal的ATT針對BLE裝置專門做的具體就是傳輸過程中使用盡量少的資料，每個屬性都有個唯一的UUID，屬性chartcteristics and Service的形式傳輸。

(3)、Service是Characteristic的集合。
(4)、Characteristic 特徵類型。

比如，有個藍芽ble的血壓計。他可能包括多個Servvice，每個Service有包括多個Characteristic

注意：藍芽ble只能支援Android 4.3以上的系統 SDK>=18

2.以下是開發的步驟：
2.1首先擷取BluetoothManager 

複製代碼 代碼如下:

BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE); 

2.2擷取BluetoothAdapter

複製代碼 代碼如下:

BluetoothAdapter mBluetoothAdapter = bluetoothManager.getAdapter(); 

2.3建立BluetoothAdapter.LeScanCallback

private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {    @Override   public void onLeScan(final BluetoothDevice device, int rssi, final byte[] scanRecord) {     runOnUiThread(new Runnable() {     @Override     public void run() {      try {       String struuid = NumberUtils.bytes2HexString(NumberUtils.reverseBytes(scanRecord)).replace("-", "").toLowerCase();       if (device!=null && struuid.contains(DEVICE_UUID_PREFIX.toLowerCase())) {        mBluetoothDevices.add(device);       }      } catch (Exception e) {       e.printStackTrace();      }     }    });   }  }; 

2.4.開始搜尋裝置。

複製代碼 代碼如下:

mBluetoothAdapter.startLeScan(mLeScanCallback); 

2.5.BluetoothDevice  描述了一個藍牙裝置 提供了getAddress()裝置Mac地址,getName()裝置的名稱。
2.6開始串連裝置

 /**   * 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. (先前串連的裝置。 嘗試重新串連)   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;  } 

2.7串連到裝置之後擷取裝置的服務(Service)和服務對應的Characteristic。

// Demonstrates how to iterate through the supported GATT // Services/Characteristics. // In this sample, we populate the data structure that is bound to the // ExpandableListView // on the UI. private void displayGattServices(List<BluetoothGattService> gattServices) {  if (gattServices == null)   return;  String uuid = null;  ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<>();  ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<>();   mGattCharacteristics = new ArrayList<>();   // Loops through available GATT Services.  for (BluetoothGattService gattService : gattServices) {   HashMap<String, String> currentServiceData = new HashMap<>();   uuid = gattService.getUuid().toString();   if (uuid.contains("ba11f08c-5f14-0b0d-1080")) {//服務的uuid    //System.out.println("this gattService UUID is:" + gattService.getUuid().toString());    currentServiceData.put(LIST_NAME, "Service_OX100");    currentServiceData.put(LIST_UUID, uuid);    gattServiceData.add(currentServiceData);    ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<>();    List<BluetoothGattCharacteristic> gattCharacteristics = gattService.getCharacteristics();    ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<>();     // Loops through available Characteristics.    for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {     charas.add(gattCharacteristic);     HashMap<String, String> currentCharaData = new HashMap<>();     uuid = gattCharacteristic.getUuid().toString();     if (uuid.toLowerCase().contains("cd01")) {      currentCharaData.put(LIST_NAME, "cd01");     } else if (uuid.toLowerCase().contains("cd02")) {      currentCharaData.put(LIST_NAME, "cd02");     } else if (uuid.toLowerCase().contains("cd03")) {      currentCharaData.put(LIST_NAME, "cd03");     } else if (uuid.toLowerCase().contains("cd04")) {      currentCharaData.put(LIST_NAME, "cd04");     } else {      currentCharaData.put(LIST_NAME, "write");     }      currentCharaData.put(LIST_UUID, uuid);     gattCharacteristicGroupData.add(currentCharaData);    }     mGattCharacteristics.add(charas);     gattCharacteristicData.add(gattCharacteristicGroupData);     mCharacteristicCD01 = gattService.getCharacteristic(UUID.fromString("0000cd01-0000-1000-8000-00805f9b34fb"));    mCharacteristicCD02 = gattService.getCharacteristic(UUID.fromString("0000cd02-0000-1000-8000-00805f9b34fb"));    mCharacteristicCD03 = gattService.getCharacteristic(UUID.fromString("0000cd03-0000-1000-8000-00805f9b34fb"));    mCharacteristicCD04 = gattService.getCharacteristic(UUID.fromString("0000cd04-0000-1000-8000-00805f9b34fb"));    mCharacteristicWrite = gattService.getCharacteristic(UUID.fromString("0000cd20-0000-1000-8000-00805f9b34fb"));     //System.out.println("=======================Set Notification==========================");    // 開始順序監聽，第一個：CD01    mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD01, true);    mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD02, true);    mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD03, true);    mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD04, true);   }  } } 

2.8擷取到特徵之後，找到服務中可以向下位機寫指令的特徵，向該特徵寫入指令。

public void wirteCharacteristic(BluetoothGattCharacteristic characteristic) {    if (mBluetoothAdapter == null || mBluetoothGatt == null) {    Log.w(TAG, "BluetoothAdapter not initialized");    return;   }    mBluetoothGatt.writeCharacteristic(characteristic);   } 

2.9寫入成功之後，開始讀取裝置返回來的資料。

private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {   @Override   public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {    String intentAction;    //System.out.println("=======status:" + status);    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);    }   }   //從特徵中讀取資料   @Override   public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {    //System.out.println("onCharacteristicRead");    if (status == BluetoothGatt.GATT_SUCCESS) {     broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);    }   }   //向特徵中寫入資料   @Override   public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {    //System.out.println("--------write success----- status:" + status);   }    /*    * when connected successfully will callback this method this method can    * dealwith send password or data analyze       *當串連成功將回調該方法    */   @Override   public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {    broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);    if (characteristic.getValue() != null) {      //System.out.println(characteristic.getStringValue(0));    }    //System.out.println("--------onCharacteristicChanged-----");   }    @Override   public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {     //System.out.println("onDescriptorWriteonDescriptorWrite = " + status + ", descriptor =" + descriptor.getUuid().toString());     UUID uuid = descriptor.getCharacteristic().getUuid();    if (uuid.equals(UUID.fromString("0000cd01-0000-1000-8000-00805f9b34fb"))) {     broadcastUpdate(ACTION_CD01NOTIDIED);    } else if (uuid.equals(UUID.fromString("0000cd02-0000-1000-8000-00805f9b34fb"))) {     broadcastUpdate(ACTION_CD02NOTIDIED);    } else if (uuid.equals(UUID.fromString("0000cd03-0000-1000-8000-00805f9b34fb"))) {     broadcastUpdate(ACTION_CD03NOTIDIED);    } else if (uuid.equals(UUID.fromString("0000cd04-0000-1000-8000-00805f9b34fb"))) {     broadcastUpdate(ACTION_CD04NOTIDIED);    }   }    @Override   public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {    //System.out.println("rssi = " + rssi);   }  };    ----------------------------------------------   //從特徵中讀取資料   @Override   public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {    //System.out.println("onCharacteristicRead");    if (status == BluetoothGatt.GATT_SUCCESS) {     broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);    }   } 

2.10、中斷連線

/**   * 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();  } 

2.11、資料的轉換方法

// byte轉十六進位字串  public static String bytes2HexString(byte[] bytes) {   String ret = "";   for (byte aByte : bytes) {    String hex = Integer.toHexString(aByte & 0xFF);    if (hex.length() == 1) {     hex = '0' + hex;    }    ret += hex.toUpperCase(Locale.CHINA);   }   return ret;  } 

/**   * 將16進位的字串轉換為位元組數組   *   * @param message   * @return 位元組數組   */  public static byte[] getHexBytes(String message) {   int len = message.length() / 2;   char[] chars = message.toCharArray();   String[] hexStr = new String[len];   byte[] bytes = new byte[len];   for (int i = 0, j = 0; j < len; i += 2, j++) {    hexStr[j] = "" + chars[i] + chars[i + 1];    bytes[j] = (byte) Integer.parseInt(hexStr[j], 16);   }   return bytes;  } 

大概整體就是如上的步驟，但是也是要具體根據廠家的協議來實現通訊的過程。

就拿一個我們項目中的demo說一下。
一個藍芽ble的血壓計。 上位機---手機  下位機 -- 血壓計
1.血壓計與手機串連藍芽之後。
2.上位機主動向下位機發送一個身分識別驗證指令，下位機收到指令後開始給上位做應答，
3.應答成功，下位機會將測量的血壓資料傳送到上位機。
4.最後中斷連線。

希望本文對大家學習Android藍芽技術有所協助。