Stepper Motor Controller

The microcontroller receives commands from a computer via its serial port.  The computer instructs the microcontroller as to which direction to rotate, how far to rotate, and how fast to rotate.  The microcontroller, after receiving the commands, steps the motor and sends a response to the computer letting it know it is ready to receive new instructions.  Each motor controller has it's own address allowing up to 16 controllers to be daisy chained together on the same serial port.  This device is being used to automatically adjust the magnet current in an ion beam experiment in Dr. Farley's Lab