如何将数据传输到连接的蓝牙LE设备

Question

I connected to a bluetooth LE device with below instructions and samples: https://developer.android.com/reference/android/bluetooth/BluetoothGatt.html#getService(java.util.UUID)

https://github.com/googlesamples/android-BluetoothLeGatt

but i have no idea how i can send data (hexa code) to ble device, can anyone help me? does below code send data to device :

BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
int hexaCode =Integer.parseInt("7c",16);
descriptor.setValue( 
ByteBuffer.allocate(4).putInt(hexaCode).array());
mBluetoothGatt.writeDescriptor(descriptor);

Answer 1

BLE receive data only on services. Services can be custom or BLE standers.ON device connect discover all Ble services and find-out all available service(with there UUIDs and capabilities) on that device.You can download nordic semiconductors nRF connect application for better understanding of BLE read and write