Serial Control of a 12V DC Motor

This very basic exmaple shows how to communicate with a BV4113 serial controller. 
The BV4113 is a typical serial controller that can control both DC motors and stepper motors.

The example here just initiates comms with the controller and then offers only full speed forward/reverse or stop. 
The BV4113 can alter the duty cycle of the output voltage to give incremental control of the motor speed.

This works on Windows XP with a standard serial port and with a Keyspan USB to serial adapter.
It also works on Macintosh OS X and OS 9.
