I´m developing an BLE app, based on the Gatt sample project provided by google: https://developer.android.com/samples/BluetoothLeGatt/index.html. So, I can send data writing in a characteristic successfully. Now I need to know when this characteristic change its value. I understand that I need to implement the setCharacteristicNotification() method and the onDescriptorWrite() method. But I cant do that this works. Searching, I found some ideas about that: Android BLE API: GATT Notification not received, What are the steps to get notified …