I am trying to connect to a ZD410 not using the link-os SDK, but the standard Android SDK. This succeeds without problems using the standard BluetoothGatt and related classes. To then print on the ZD410 I write to the Characteristic of which the UUID (38eb4a82-c570-11e3-9507-0002a5d5c51b) can be found in the PDF "Bluetooth Low Energy Printing – iOS". I split the zpl code I want to print into 20 byte chunks and write it to the Characteristic, writing one chunk after the onCharacteristic write of the BluetoothGattCallback tells me the last write was completed. This also works without problems until I disconnect() and close() the current BluetoothGatt and later construct a new one using BluetoothDevice.connectGatt(). If I then try to write to the Characteristic, onCharacteristicWrite will be called with a Characteristic, that still has the old value from before the disconnect. At the same time the data LED on the ZD410 will be green and stay that way without blinking. How can I fix this?