I decided to use my little Arduino to make a robot. After a few days of Googling I decided to start with a small 2 wheel robot: DFRobot’s 2WD Mobile Platform (link). It should be easy to control, it can turn on its center (with a small turning radius), it is compatible with Arduino and its big library of freely available samples, and there are a lot of compatible sensors.
After a few hours spent with screws, cables, and batteries it is already wandering around the room! But a small issue appears: it can’t go straight as-is, out of the box! Motors are not created equals: one may be a bit more efficient than the other, the motor shield may give a bit more voltage to one of them, and so on. So the must-have accessory to let it go straight is a couple of Wheel Encoders (link): one can easly extract them from an old (ancient) ball mouse!
Marco Altomonte 