Making a servo tester using an Attiny85 micro chip, Attiny45 also works for this project. This diy servo tester is as good as ...

Rather than write a bunch of stepper motor code himself, he installed and ran a four-axis fork of grbl on the Arduino, turning it into a stepper motor controller.

He built a servo tester and demonstrator based on an Arduino, and went the extra mile to give it a good UI and a bunch of functionality.