android蓝牙4.0多通道功能示例

2015-07-06 21:48:21   来源:互联网   评论: 点击:

需要使用android版本4 3以上,蓝牙4 0及以上,这里使用的控制蓝牙灯泡,使用android4 3的手机,手机上的蓝牙是4 0
很久没记录东西了,前段时间研究了一哈android4.0控制多个外设的情况,注意,需要使用android版本4.3以上,蓝牙4.0及以上。

我这里使用的控制蓝牙灯泡,使用android4.3的手机,手机上的蓝牙是4.0.

记得在manifest文件中加入权限:

<uses-permission android:name="android.permission.BLUETOOTH" />
 <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

先拿到BluetoothManager和BluetoothAdapter的对象。

        // 初始化 Bluetooth adapter, 通过蓝牙管理器得到一个参考蓝牙适配器(API必须在以上android4.3或以上和版本)
        final BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();

        // 检查设备上是否支持蓝牙
        if (mBluetoothAdapter == null) {
            Toast.makeText(this, R.string.error_bluetooth_not_supported,Toast.LENGTH_SHORT).show();
            finish();
            return;
        }

看下是否开启了蓝牙,如果没有开启,跳转到设置去开启蓝牙。

// 为了确保设备上蓝牙能使用, 如果当前蓝牙设备没启用,弹出对话框向用户要求授予权限来启用
        if (!mBluetoothAdapter.isEnabled()) {
            if (!mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
            }
        }

调用startScan方法开始扫描,stopScan方法停止扫描,扫描到的设备都在回调函数里。

private void scanLeDevice(final boolean enable) {
  if (enable) {
    // Stops scanning after a pre-defined scan period.
    mHandler.postDelayed(new Runnable() {
      @Override
      public void run() {
        mScanning = false;
        mBluetoothAdapter.stopLeScan(mLeScanCallback);
        invalidateOptionsMenu();
      }
    }, SCAN_PERIOD);
    mScanning = true;
    mBluetoothAdapter.startLeScan(mLeScanCallback);
  } else {
    mScanning = false;
    mBluetoothAdapter.stopLeScan(mLeScanCallback);
  }
  invalidateOptionsMenu();
}
// Device scan callback.
  private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
    @Override
    public void onLeScan(final BluetoothDevice device, int rssi,
        byte[] scanRecord) {
      runOnUiThread(new Runnable() {
        @Override
        public void run() {
          mLeDeviceListAdapter.addDevice(device);
//					mLeDeviceListAdapter.notifyDataSetChanged();
        }
      });
    }
  };

扫描后的BluetoothDevice加入到列表中,这时列表中就会有设备,通过getName可以获取设备的蓝牙名字,getAddress获取设备的蓝牙地址。

列表出来了之后,点击某个设备进行连接。

注意这里的连接跟2.0的蓝牙的连接不一样,通过设备的connectGatt方法进行连接,连接完成后会获得一个BluetoothGatt的对象,这个对象中有连接的一些重要信息,切记要保存好。

public boolean connect(final String address) {
  if (mBluetoothAdapter == null || address == null) {
    Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
    return false;
  }
  if (mBluetoothDeviceAddress != null
      && address.equals(mBluetoothDeviceAddress)
      && mBluetoothGatt != null) {
    Log.d(TAG,
        "Trying to use an existing mBluetoothGatt for connection.");
    if (mBluetoothGatt.connect()) {
      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.
  Log.e("AAA", "222");
  mBluetoothGatt = device.connectGatt(this, true, mGattCallback);
  Log.d(TAG, "Trying to create a new connection.");
  mBluetoothDeviceAddress = address;
  bluetoothGatts.add(mBluetoothGatt);
  return true;
}

连接时有一个回调函数mGattCallback,这个函数中有很多设备的相关信息,比如设备的状态啊,设备中的通道哈,一些服务啊之类的。

// 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) {
  System.out.println("onConnectionStateChange");
  String intentAction;
  if (status == BluetoothProfile.STATE_DISCONNECTED
    && newState == BluetoothProfile.STATE_CONNECTED) {
      intentAction = ACTION_GATT_CONNECTED;
      Log.i(TAG, "Connected to GATT server.");
      // Attempts to discover services after successful connection.
      Log.i(TAG, "Attempting to start service discovery:"
        + mBluetoothGatt.discoverServices());
      Log.e("dongpuxiao", "连接成功");
      mHandler.sendEmptyMessage(MESSAGE_START_SUCCESS);
  } else if (status == BluetoothProfile.STATE_DISCONNECTED
    && newState == BluetoothProfile.STATE_DISCONNECTED) {
      intentAction = ACTION_GATT_DISCONNECTED;
      setConnStatus(false);
      Log.e("dongpuxiao", "连接失败");
      Log.i(TAG, "Disconnected from GATT server.");
      mHandler.sendEmptyMessage(STATE_CONNECTFAILED);
  }
    }
    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
  System.out.println("onServicesDiscovered-----");
  if (status == BluetoothGatt.GATT_SUCCESS) {
      broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
      displayGattServices(getSupportedGattServices());
      mHandler.sendEmptyMessage(MESSAGE_BLUETOOTH_INIT);
  } else {
      Log.w(TAG, "onServicesDiscovered received: " + status);
  }
    }
    @Override
    public void onCharacteristicRead(BluetoothGatt gatt,
      BluetoothGattCharacteristic characteristic, int status) {
  System.out.println("onCharacteristicRead");
  if (status == BluetoothGatt.GATT_SUCCESS) {
      broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
  }
    }
    @Override
    public void onDescriptorWrite(BluetoothGatt gatt,
      BluetoothGattDescriptor descriptor, int status) {
  System.out.println("onDescriptorWriteonDescriptorWrite = " + status
    + ", descriptor =" + descriptor.getUuid().toString());
    }
    @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 onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
    }
    public void onCharacteristicWrite(BluetoothGatt gatt,
      BluetoothGattCharacteristic characteristic, int status) {
  System.out.println("--------write success----- status:" + status);
    };
};

连接时会走这个方法onConnectionStateChange,传过来的新状态是连接状态,这时在这个方法中调用一下这句:mBluetoothGatt.discoverServices(),

mBluetoothGatt是连接完成时的对象,还记得吧,调用这句后,会走回调函数的onServicesDiscovered方法。在这个方法中去获取设备的一些服务,蓝牙通道,然后通过这些通道去发送数据给外设。

查看该外设中支持的一些服务通道:

public List<BluetoothGattService> getSupportedGattServices() {
        if (mBluetoothGatt == null)
            return null;

        return mBluetoothGatt.getServices();
    }
// 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<HashMap<String, String>>();
  ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<ArrayList<HashMap<String, String>>>();
  mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>();
  // Loops through available GATT Services.
  for (BluetoothGattService gattService : gattServices) {
    HashMap<String, String> currentServiceData = new HashMap<String, String>();
    uuid = gattService.getUuid().toString();
    gattServiceData.add(currentServiceData);
    ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<HashMap<String, String>>();
    List<BluetoothGattCharacteristic> gattCharacteristics = gattService
        .getCharacteristics();
    ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<BluetoothGattCharacteristic>();
    // Loops through available Characteristics.
    for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
      charas.add(gattCharacteristic);
      HashMap<String, String> currentCharaData = new HashMap<String, String>();
      uuid = gattCharacteristic.getUuid().toString();
      gattCharacteristicGroupData.add(currentCharaData);
    }
    mGattCharacteristics.add(charas);
    gattCharacteristicData.add(gattCharacteristicGroupData);
  }
  bluetoothGattChacteristics.add(mGattCharacteristics);
}

然后就可以通过Gatt这个对像,就是蓝牙连接完成后获取到的对象,通过这个对象设置好指定的通道向设备中写入和读取数据。

写数据:

public void wirteCharacteristic(BluetoothGattCharacteristic characteristic) {

        if (mBluetoothAdapter == null || mBluetoothGatt == null) {
            Log.w(TAG, "BluetoothAdapter not initialized");
            return;
        }

        mBluetoothGatt.writeCharacteristic(characteristic);
    }

读数据:

/**
 * 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);
}

注意:BluetoothGattCharacteristic这个是指定的通道,蓝牙服务:

BluetoothGattCharacteristic characteristic = null;
characteristic = mGattCharacteristics.get(4).get(4);

这两个数字就是从指定的服务中找到你要发送数据的那个服务。

最后,如果要进行多个连接,每次连接完成后可以将BluetoothGatt的对象放到一个list里面,获取到的服务也放到一个List里面,然后发送数据的时候调用不同的Gatt发送不同的通道数据即可。

关于蓝牙4.0的BluetoothLeGatt连接,android Samples有一个例子,发上来吧,需要的朋友可以下载看看。

BluetoothLeGatt

相关热词搜索:蓝牙 android4 0

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