This is a video tutorial of the basic concept on how to control a DC motor from ordinary personal computer.
By using a few widely available modular components, you can create a flexible system that can be used to control a DC motor. Start by selecting a DC motor that will meet the demands of your project, then a motor controller that can provide sufficient power to the motor. Add an appropriate servo controller to generate the R/C control signals, and software to issue commands to the servo controller, and you’re ready to roll! If you need to monitor the motor speed, feedback is easily achieved by adding an optical encoder.
In this video, there is no circuit diagram of motor provided. All module is already prepared and you should buy/build the motor controller and Encoder first before practicing this tutorial.
Source: tossen robotics