"Just do it!"

I think it's worth the effort in any case. No matter if you win some price or not. If you have fun coding and you improve your skills you are already a winner.

As for the technical side: I would suggest to go with QML. One has to differentiate between the Qt C++ stuff and QML quite heavily.
QML itself is, I'd say, pretty easy to learn and you have the benefit (development-wise) that it is interpreted. Hence, you can easily hack on your device and develop very quickly without needing any compile steps.
And if you go with PySide (that's the python binding stuff for Qt) you gain even more flexibility. But, honestly, I don't know if PySide is actually maintained currently and if there are aims to port it to Qt 5.