https://duckduckgo.com/?q=stepper+motor+nema17+inside&iax=images&ia=images
https://en.wikipedia.org/wiki/Stepper_motor
https://es.wikipedia.org/wiki/Motor_paso_a_paso
https://www.schmalzhaus.com/EasyDriver/Examples/EasyDriverExamples.html
https://www.pololu.com/category/120/stepper-motor-drivers