Electronics Projects: How to Build a Motor Driver
This project presents a breadboard circuit that drives a small 3 V DC motor from a parallel port. Because this motor uses much more current than a parallel port can handle, a ULN2003 darlington array IC is used to drive the motor.
To work this project, you need a computer with a parallel port and the Kit 74 software installed, plus a parallel-port connector with wires soldered to the data pins and one of the common data ground pins.
When the circuit is assembled and connected to your computer, you can test it by running the following command twice in a command window:
The motor should start running. To stop the motor, use this command twice:
You can easily write a script to run the motor for a certain interval. Here, the MOTOR.BAT file simply runs the motor for 30 seconds, turns it off for 30 seconds, and then jumps to the :LOOP label to repeat the cycle.
MOTOR.BAT :LOOP RELAY 01 RELAY 01 DELAY 30 RELAY 00 RELAY 00 DELAY 30 GOTO LOOP