Stepper Motors

1. Stepper Motors have multiple coils, which can be activated separately to step the motor through specific sequences. They are accurate positional motors and therefore the BS2 counts through a sequence and the motor can proceed through that sequence. Stepper motors are the ideal motors for creating XY positioning tables, such as the one Shawn Brixey and Richard Rienhart used in their collaborative project Chimera Obscura.
2. Chimera Obscura. Is a network based-telerobotic artwork, which was inspired by anxieties and eugenic fantasies surrounding contemporary genetics research.

This collaborative project creates a discourse on human evolution, which arises out of interest and concern with the Human Genome Project.

Stepper motors are the motors you will generally find in common commercial printers that drive belts on linear bearings. They can be controlled with special stepper driving chips. You can use the LM2803 and step the motor through its sequences using your microcontroller. The ULN2803 are a series of Darlington transistors in a DIP array, which can function as a power motor driver.

A better way to drive a unipolar stepper motor is to use a special function chip. The UCN5804 and the new allegro SLA7060M thru SLA7062M Unipolar Stepper-Motor Translator/Driver allows you to take the signal from the microprocessor, and with either a high or a low pulse, control the speed of the motor and the direction. This specialty chip also has a half-step function to provide more accuracy of stepping forward or back. The UCN5804 stepper driver can replace many other parts in this simple DIP 16 pin package. The driver handle motors up to 35V at 1.25A .

Stepper motors are relatively easy to use once you have determined your coils, and they become much easier to use with a specialty stepper driving chip.