Android BLE接收的设置的小坑

一个蓝牙接收框架,在TI CC2541下工作正常,接收采用Notify字符进行接收.

在查找到这个Characteristic后,如下方法设置通知可以.

boolean ret = mBluetoothGatt.setCharacteristicNotification(mRxChar,true);

然后在蓝牙回调函数中的接收数据

public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic)

但是这套代码切换到NORDIC 51822环境下可以扫描,联接,发送,但就是不能接收.

在Nordic的官方的nRF ToolBox的源码中,经过查阅分析后发现,是setCharacteristicNotification()不能真正打开Notify 接收通知.于把其初始化方法摘出来放在蓝牙库中,一试果然能接收,特的记录下,其中的enableNotifications就是nRF的初始化方法,在

 private static final UUID CLIENT_CHARACTERISTIC_CONFIG_DESCRIPTOR_UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb");
 /**
  * Enables notifications on given characteristic
  *
  * @return true is the request has been sent, false if one of the arguments was <code>null</code> or the characteristic does not have the CCCD.
  */
 protected final boolean enableNotifications(final BluetoothGattCharacteristic characteristic) {
  final BluetoothGatt gatt = mBluetoothGatt;
  if (gatt == null || characteristic == null)
   return false;

  // Check characteristic property
  final int properties = characteristic.getProperties();
  if ((properties & BluetoothGattCharacteristic.PROPERTY_NOTIFY) == 0)
   return false;

  Log.d("BLE", "gatt.setCharacteristicNotification(" + characteristic.getUuid() + ", true)");
  gatt.setCharacteristicNotification(characteristic, true);
  final BluetoothGattDescriptor descriptor = characteristic.getDescriptor(CLIENT_CHARACTERISTIC_CONFIG_DESCRIPTOR_UUID);
  if (descriptor != null) {
   descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
   Log.v("BLE", "Enabling notifications for " + characteristic.getUuid());
   Log.d("BLE", "gatt.writeDescriptor(" + CLIENT_CHARACTERISTIC_CONFIG_DESCRIPTOR_UUID + ", value=0x01-00)");
   return gatt.writeDescriptor(descriptor);
  }
  return false;
 }

 /**
  * Enables indications on given characteristic
  *
  * @return true is the request has been sent, false if one of the arguments was <code>null</code> or the characteristic does not have the CCCD.
  */
 protected final boolean enableIndications(final BluetoothGattCharacteristic characteristic) {
  final BluetoothGatt gatt = mBluetoothGatt;
  if (gatt == null || characteristic == null)
   return false;

  // Check characteristic property
  final int properties = characteristic.getProperties();
  if ((properties & BluetoothGattCharacteristic.PROPERTY_INDICATE) == 0)
   return false;

  Log.d("BLE", "gatt.setCharacteristicNotification(" + characteristic.getUuid() + ", true)");
  gatt.setCharacteristicNotification(characteristic, true);
  final BluetoothGattDescriptor descriptor = characteristic.getDescriptor(CLIENT_CHARACTERISTIC_CONFIG_DESCRIPTOR_UUID);
  if (descriptor != null) {
   descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);
   Log.v("BLE", "Enabling indications for " + characteristic.getUuid());
   Log.d("BLE", "gatt.writeDescriptor(" + CLIENT_CHARACTERISTIC_CONFIG_DESCRIPTOR_UUID + ", value=0x02-00)");
   return gatt.writeDescriptor(descriptor);
  }
  return false;
 }

为了保险,两个初始化方法都写上,这样蓝牙库在TI和Nodic下均能正常接收了!

mBluetoothGatt.setCharacteristicNotification(mRxChar,true);
//nRF 芯片必须带这个
enableNotifications(mRxChar);