Im in the same exact boat!!! I have an Arduino uno+R3 motor shield with a nemea 23 stepper but it had 6 wires. According to wiring diagram the green and black was one coil and the red and blue was the other, then directions i found stated to have the center taps, in my case white and yellow connected to ground. I then plugged in black to A+ and Green to A- , then Red to B+ and Blue to B- I took the white and yellow twisted together and connected to the GND terminal. which I can't verify that it works cause the code below sort of moves the motor, the shaft sort of vibrates and when it gets to what i think is wave the flag the motor shaft turns a little:
#include <Stepper.h> //include the function library
#define STEPS 200 //1.8 deg motor (200 steps per rev)
Stepper stepper(STEPS, 12, 13); //create the stepper
void setup()
{
int i;
stepper.setSpeed(30); //set speed to 30 rpm
delay(1000); //pause for effect
stepper.step(200); //move 360 deg one direction
delay(1000); //pause for effect
stepper.step(-200); //move 360 deg in the other direction
delay(1000); //pause
stepper.setSpeed(60); //speed up
for (i=0;i<5;i++) {
stepper.step(20); //wave the flag
stepper.step(-20);
}
}
void loop()
{}
If any of you guys see something wrong with the code or the wiring for the motor let me know. the Arduino book I have by Simon Monk arrived and turned out to not have anything about wiring up steppers. Which is frustrating