蓝牙GATT readCharacteristic返回false

Question

我正在尝试连接蓝牙健康温度计。我可以找到设备并连接到该设备，但是当我想读取特征时，readCharacteristics调用将返回false。

我的代码是：

private void connectDevice(BluetoothDevice bluetoothDevice) {
    mBluetoothGatt = bluetoothDevice.connectGatt(getContext(), true, mGattCallback);
}

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            // Discovery has found a device. Get the BluetoothDevice
            // object and its info from the Intent.
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            String deviceName = device.getName();
            String deviceHardwareAddress = device.getAddress(); // MAC address

            if(deviceName != null) {
                Device btDevice = new Device(device);
                if(mDevices.contains(btDevice)) {
                    mDevices.remove(btDevice);
                }
                mDevices.add(btDevice);
                mDeviceAdapter.notifyDataSetChanged();
            }

            Log.i("Device Name: " , "device " + deviceName);
            Log.i("deviceHardwareAddress " , "hard"  + deviceHardwareAddress);
        }
    }
};

BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {

    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        if (newState == BluetoothProfile.STATE_CONNECTED) {
            Timber.d("Connected to GATT client. Attempting to start service discovery");
            gatt.discoverServices();
        } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
            Timber.d("Disconnected from GATT client");
        }
    }

    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        if (status != GATT_SUCCESS) {
            // Handle the error
            return;
        }

        // Get the counter characteristic
        BluetoothGattCharacteristic characteristic = gatt
                .getService(HEALTH_THERMOMETER_SERVICE_UUID)
                .getCharacteristic(HEALTH_THERMOMETER_CHARACTERISTIC_UUID);

        // Enable notifications for this characteristic locally
        gatt.setCharacteristicNotification(characteristic, true);

        // Write on the config descriptor to be notified when the value changes
        BluetoothGattDescriptor descriptor =
                characteristic.getDescriptor(DESCRIPTOR_CONFIG_UUID);
        descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
        gatt.writeDescriptor(descriptor);
    }

    @Override
    public void onCharacteristicRead(BluetoothGatt gatt,
                                     BluetoothGattCharacteristic characteristic, int status) {
        readCounterCharacteristic(characteristic);
    }

    private void readCounterCharacteristic(BluetoothGattCharacteristic
                                                   characteristic) {
        if (HEALTH_THERMOMETER_CHARACTERISTIC_UUID.equals(characteristic.getUuid())) {
            byte[] data = characteristic.getValue();
            Timber.d(data.toString());
        }
    }

    @Override
    public void onDescriptorWrite(BluetoothGatt gatt,
                                  BluetoothGattDescriptor descriptor, int status) {
        if (DESCRIPTOR_CONFIG_UUID.equals(descriptor.getUuid())) {
            BluetoothGattCharacteristic characteristic = gatt
                    .getService(HEALTH_THERMOMETER_SERVICE_UUID)
                    .getCharacteristic(HEALTH_THERMOMETER_CHARACTERISTIC_UUID);
            boolean read = gatt.readCharacteristic(characteristic);
            Timber.d(String.valueOf(read));
        }
    }

    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        super.onCharacteristicChanged(gatt, characteristic);
        Timber.d("onCharacteristicChanged");
    }


};