QUdpSocket: Is not emitting signal readReady when used as a QIODevice (read(), readline(), write())

I'm trying to use QUdpSocket as a QIODevice. I bind the socket to port I would like to liston on and then use the connectToHost(...) to connect to the broadcast address. At this stage, write() works as expected, but I never get any readyRead signal. I have attached a small example to show the problem.