@Chuck While this does seem to be close to what I need, I believe it is lacking in a specific manner. It does not have any way of knowing whether there is something in front of it, if it can go higher etc.

Since the point isn't to make it work for a specific room, I can't ask it to move straight for 2 secs and hope nothing will be there.

However, it does seem a good solution since I'm not interested that much in the hardware, rather that the software. Dunno if I could stick an arduino there with some IR or ultrasonic sensors and have the arduino tell it what to do.