Using Arduino Stepper library to control 28BYJ-48 stepper motor with L293D H-bridge

stepper_control.ino

/*
 * Example code for controlling a 28BYJ-48 stepper motor through an L293D H-Bridge
 */

// Include the Arduino Stepper.h library
#include <Stepper.h>

/*
 * Motor outputs from the 28BYj-48:
 * 1 - blue ------|
 * 2 - pink ---|  |-- coils A and A'
 * 3 - yellow -|--|
 * 4 - orange _|_____ coils B and B'
 * 5 - red .......... reversible power
 */

const int STEPS_PER_REVOLUTION = 2048;
const int MAX_SPEED = 14; // revolutions per minute

/*
 * L293D H-bridge wiring                        
 *                                ----------\_/---------   
 * 5V (NOT arduino, if possible) -|Enable 1        Vss |- 5V (NOT arduino if possible)
 *            digital I/O pin 12 -|Input 1     Input 4 |- digital I/O pin 9
 *            motor pin 1 (blue) -|Output 1   Output 4 |- motor pin 4 (orange)
 *                        Ground -|Ground       Ground |-
 *                               -|Ground       Ground |-
 *          motor pin 3 (yellow) -|Output 2   Output 3 |- motor pin 2 (pink)
 *            digital I/O pin 11 -|Input 2     Input 3 |- digital I/O pin 10
 * 5V (NOT arduino, if possible) -|Vs         Enable 2 |- 5V (NOT arduino if possible)
 *                                ---------------------
 */

const int INPUT1 = 12;
const int INPUT2 = 11;
const int INPUT3 = 10;
const int INPUT4 = 9;

Stepper myStepper = Stepper(STEPS_PER_REVOLUTION, INPUT1, INPUT2, INPUT3, INPUT4);

void setup() {
  myStepper.setSpeed(MAX_SPEED);
  Serial.begin(9600);
}

void loop() {
  // Step one revolution in one direction:
  Serial.println("revolving clockwise");
  myStepper.step(STEPS_PER_REVOLUTION);
  delay(2000);

  // Step one revolution in the other direction:
  Serial.println("revolvingg counter-clockwise");
  myStepper.step(-STEPS_PER_REVOLUTION);
  delay(2000);
}