Control a Stepper Motor using Arduino and Rotary Encoder

rotary.c

#include <Stepper.h>

/*-----( Declare Constants, Pin Numbers )-----*/
int in1 = 2;
int in2 = 3;
int in3 = 4;
int in4 = 5;

// init rotary encoder
int pinA = 7;
int pinB = 8;
int encoderPosCount = 0;
int pinALast;
int aVal;
int bVal;
boolean bCW;

//---( Number of steps per revolution of INTERNAL motor in 4-step mode )---
#define STEPS_PER_MOTOR_REVOLUTION 32   

//---( Steps per OUTPUT SHAFT of gear reduction )---
#define STEPS_PER_OUTPUT_REVOLUTION 32 * 64  //2048  

/*-----( Declare objects )-----*/
// create an instance of the stepper class, specifying
// the number of steps of the motor and the pins it's
// attached to

//The pin connections need to be 4 pins connected
// to Motor Driver In1, In2, In3, In4  and then the pins entered
// here in the sequence 1-3-2-4 for proper sequencing
Stepper small_stepper(STEPS_PER_MOTOR_REVOLUTION, 2, 4, 3, 5);


/*-----( Declare Variables )-----*/
int  Steps2Take;

void setup()   /*----( SETUP: RUNS ONCE )----*/
{
// rotary encoder setup
pinMode(pinA, INPUT);
pinMode(pinB, INPUT);
pinALast = digitalRead(pinA);
Serial.begin(9600);
// Nothing  (Stepper Library sets pins as outputs)
}/*--(end setup )---*/

void loop()   /*----( LOOP: RUNS CONSTANTLY )----*/
{
  aVal = digitalRead(pinA);
  bVal = digitalRead(pinB);

  if ((pinALast == HIGH) && (aVal == LOW)){
    if (bVal == LOW){
       Steps2Take  = STEPS_PER_OUTPUT_REVOLUTION / 50;  // Rotate CW 1/2 turn
       small_stepper.setSpeed(500);   
       small_stepper.step(Steps2Take);

       digitalWrite(in1, LOW);
       digitalWrite(in2, LOW);
       digitalWrite(in3, LOW);
       digitalWrite(in4, LOW);

       encoderPosCount--;
    }
    else {

      Steps2Take  = - STEPS_PER_OUTPUT_REVOLUTION / 50;  // Rotate CW 1/2 turn
      small_stepper.setSpeed(500);   
      small_stepper.step(Steps2Take);

      digitalWrite(in1, LOW);
      digitalWrite(in2, LOW);
      digitalWrite(in3, LOW);
      digitalWrite(in4, LOW);

      encoderPosCount++;
    }
    Serial.print (encoderPosCount);
    Serial.print ("/");
  }
  pinALast = aVal;

}/* --(end main loop )-- */

/* ( THE END ) */