Quick Arduino script to run a stepper motor

stepper_motor.ino

/*
 *
 * Full step motor procedure
 *
 */

#include <elapsedMillis.h>

// Constants
#define STEP_PER_REVOLUTION 4 // Probably has more to do with current than steps, but will determine relationship at later point
#define RPM 100
#define LOWEST_PIN 3

// Set pins for colors
int blue  = LOWEST_PIN;
int red   = LOWEST_PIN + 1;
int green = LOWEST_PIN + 2;
int black = LOWEST_PIN + 3;
// Timer
elapsedMillis t;

// Wait to match RPM
int wait = 60000 / (RPM * STEP_PER_REVOLUTION);

// pin stage. initial assignment to blue, red, green and black respectively 
int pinStage[]={3,1,2,0};
// Pin stage matches the pattern for increment and i > 1
// 1,0,1,0
// 0,1,1,0
// 0,1,0,1
// 1,0,0,1

//int pinStage[]={0,1,2,3};
// Pin stage matches the pattern for increment and i > 1
// 0,0,1,1
// 1,0,0,1
// 1,1,0,0
// 0,1,1,0


void setup(){
    pinMode(blue, OUTPUT);
    pinMode(red, OUTPUT);
    pinMode(green, OUTPUT);
    pinMode(black, OUTPUT);
}

void loop(){
  if(t > wait){
    t -= wait;
    int i;
    for (i = 0; i < 4; i = i + 1) {
      // Values of pinStage rotates from 0:3. Only turns on 2 highest values for max torque     
      digitalWrite(LOWEST_PIN + i, ((pinStage[i] > 1) ? HIGH : LOW));    
      // Resets pinStage if too high otherwise adds 1
      pinStage[i] = (pinStage[i] == 3) ? 0 : pinStage[i] + 1;
    }
  }
}