I am trying to figure out how to power a 5V DC step motor using this tutorial: 28BYJ-48 Stepper Motor with ULN2003 driver and Arduino Uno – 42 Bots. The tutorial recommends that the step motor has its own power source. I was going to use a 9V battery. What is the best way to go from 9v -> 5v?
Also, looking at THIS tutorial says otherwise: First Test: Super StarterKit from Elegoo - Stepper Motor 5V - Hackster.io. Can I hook the step motor directly onto the uno r3?
The step motor I have is: 28BYJ-48.
You need a stepper motor driver module or shield. The voltage depends on your motor type, voltage or current controlled.
Search the forum or tutorials for stepper motor basics.
Don't use a 9V battery, they can't supply sufficient current even if you'd use a buck converter to step down the voltage.
That motor works fine at 5V and the ULN2003 driver IC; use a spare mobile phone charger or so to power it. 1-2A is enough.