Stepper motor animation and half-stepping

The above animations show a stepper operating in normal full step mode. If you need more precision, here is a technique to double the resolution by “half-stepping”: http://www.physics.ubc.ca/~kotlicki/Physics_319/MOTORSTEPTUT.html

Stepper Motor library alteration for half-stepping:
http://code.google.com/p/arduino/issues/detail?id=139