Instructions for connecting EV3 to Windows indicate that the bluetooth is used as a serial connection so for tips on setting that up on the Pi, google "bluez rfcomm"
Thank you, I will do that.
I'm not an expert on that hardware but some googling very quickly ended up with "ev3dev" which is a linux for the EV3 for development of software to run on the EV3. If the standard firmware has limited support for handling bluetooth ( or wifi ) communication maybe using this firmware gives you better control/features.
Yes I saw that. But I'd rather avoid installing that on the brick. The kids are programming too via the official MIindstorms software
Thank you for your answer.