Qt Bluetooth - How to provide a preset PIN

[strenkwalder]

Hi everyone,

I discovered the Bluetooth library from Qt a few days ago and try to implement an application that scans for devices. It the scanned device is an e-puck (a robot used in our University), it should connect to it and log all the data that it sends.

The epuck has a name: e-puck_XXXX, where XXXX is the pin of the robot.
I use Ubuntu (16.04) and if I pair the robot by hand, the software works fine.

However, if I want to perform the pairing in the application with

localDevice.requestPairing(device.address(), QBluetoothLocalDevice::Paired);

or

localDevice.requestPairing(device.address(), QBluetoothLocalDevice::AuthorizedPaired);

I get

qt.bluetooth.bluez: Failed to create pairing "org.bluez.Error.AuthenticationFailed"

which ( I assume ) happens because I need a PIN.

I was looking over the documentation and googled a lot to find a way to provide the pairing PIN. I can only Display it, but I don't know how I can hand over the PIN to QT.

I read that I am supposed to get a popup or something, but nothing shows up. SO I cannot enter a pin or such.

Can anyone help me or show me an alternative? I can also provide code but this is a more conceptual a question on how I do that and with which classes/functions????