I found this gem:
https://www.arduino.cc/en/Tutorial/StepperOneRevolution
This is an example that rotates the shaft in revolution clockwise and then one revolution counterclockwise. This is very close to what I'm looking for. I can tweak it as I get more advanced and add more features. But for now, this should suffice. It's great the page even tells me exactly what I need and has the code:
/*
Stepper Motor Control - one revolution
This program drives a unipolar or bipolar stepper motor.
The motor is attached to digital pins 8 - 11 of the Arduino.
The motor should revolve one revolution in one direction, then
one revolution in the other direction.
Created 11 Mar. 2007
Modified 30 Nov. 2009
by Tom Igoe
*/
#include <Stepper.h>
const int stepsPerRevolution = 200; // change this to fit the number of steps per revolution
// for your motor
// initialize the stepper library on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);
void setup() {
// set the speed at 60 rpm:
myStepper.setSpeed(60);
// initialize the serial port:
Serial.begin(9600);
}
void loop() {
// step one revolution in one direction:
Serial.println("clockwise");
myStepper.step(stepsPerRevolution);
delay(500);
// step one revolution in the other direction:
Serial.println("counterclockwise");
myStepper.step(-stepsPerRevolution);
delay(500);
}
But depending on whether the motor is unipolar or bipolar, it either needs:
U2004 Darlington Array (if using a unipolar stepper)
or
SN754410ne H-Bridge (if using a bipolar stepper)
I just ordered a few different motors and I'm not sure if they are bipolar or unipolar. All it says is "2 phase 4 wire"!
But here are the pics:
They are different from the pics I showed earlier. They are bigger motors (6mm diameter) which I think is more suitable for my needs.
It really annoys me that I cannot figure out if those are unipolar or bipolar. Anyone with experience with these small motors, please advise. Thanks