Stepper motors are widely used in various automation and robotics projects. You cannot apply a power supply to stepper motor and expect it to work. As steppers are special motors capable to turn around with precise steps it requires special control. This project shows one version of stepper motor controller.
This simple circuit is allows to start/stop motor and change rotating direction. It also allows controlling rotation speed with potentiometer regulator. Just remember, that steppers aren’t designed for high speed turns, they are used for correct angular turn. When stepper motor turn speed increases it looses torque – and motor becomes useless as it can’t drive higher loads. Good thing about stepper motors is that they have high stop torque – great for fixed turns.
Program code is written in assembly language and can be found here.