Testing the first character. At the moment an Arduino and 3 L293 are used to control the coils- h-bridges, each pin has a single coil. The key of this system is the magnetic interaction between the magnets that are free to move inside the pin and the retaining M2 nuts at each end. Power is used only to change from a state to the other one. The distance between the magnets and the nuts is quite important for a correct behaviour.