QLowEnergyController does not connect to nrf8001 on Android

Hi!

Currently I am playing around with the experimental Bluetooth Low Energy (BLE) features of Qt5.4. I have a small project where I want to control some lights (25x WS28001) via my Android phone (Nexus 5 Kitkat). I do this with an Arduino Uno which is connected to a BLE unit (chip: nrf8001). I used example code in Java and Android Studio to implement a first prototype. So far everything went well.

Now I want to implement the same features in Qt5.4 to learn QML. As a first step I compiled and deployed the Qt example lowenergyscanner to my Android phone. At first the device was not recognized by the app. This is due to the fact that in the example the addDevice() method checks for the coreConfigurations() flag. This should be QBluetoothDeviceInfo::LowEnergyCoreConfiguration for my device but the device info could not be determined. So I removed the check and the device could be found. The device info has the correct name and the correct device address. Afterwards I try to connect to the device via QLowEnergyController's connectToDevice() method (correct address of the device was provided to the c'tor). The connection couldn't be set up. If I ask the controller for the error message with errorString() the result ist "Unkown error". I can't figure out what is going wrong here.

I checked the implementation of the controller for android here: http://code.woboq.org/qt5/qtconnecti...droid.cpp.html but I can't find a hint.

To avoid problems with my Arduino BLE API I tried another one from here (I also have a connected temperature sensor DHT11): https://github.com/sandeepmistry/arduino-BLEPeripheral but the issue remains. Other Android applications such as Bluetooth LE Scanner and my own Java based implementation are working as expected and are able to connect to my device.

Has anyone a working similar setup or can help me out?