One of the recurring themes of science fiction is the robot. From such icons as C-3PO and R2D2 in Star Wars to WALL-E and Eve, robots have always had a certain appeal. Inexpensive microcontrollers … ...

The Arduino controls what amounts to an upside-down 3D printer. Instead of a hot end pointing down, the mechanism has an electromagnet pointing up. A small washer in the base of each chess piece ...