how to drive a stepper motor without using stepper driver?. I know that stepper motor can be driven using pulse width modulation and it can be achieved by using port pins. what are all the other requirements we have to consider?(timer channel...)
Yes, there are of course some significant differences between the theory and practice of things. Mechanical properties of the system connected to the motor as well as imperfections in the motor's construction, etc. make driving it with a perfect sine wave less than possible. But using 1/8th stepping, say, instead of full or half stepping can give some dramatically increased smoothness, increased positional accuracy, and decreased torque ripple if done properly.