//www.elegoo.com
//2016.12.12

include “Stepper.h”

define STEPS 32 // Number of steps for one revolution of Internal shaft

                // 2048 steps for one revolution of External shaft

volatile boolean TurnDetected; // need volatile for Interrupts
volatile boolean rotationdirection; // CW or CCW rotation

const int PinCLK=2; // Generating interrupts using CLK signal
const int PinDT=3; // Reading DT signal
const int PinSW=4; // Reading Push Button switch

int RotaryPosition=0; // To store Stepper Motor Position

int PrevPosition; // Previous Rotary position Value to check accuracy
int StepsToTake; // How much to move Stepper

// Setup of proper sequencing for Motor Driver Pins
// In1, In2, In3, In4 in the sequence 1-3-2-4
Stepper small_stepper(STEPS, 8, 10, 9, 11);

// Interrupt routine runs if CLK goes from HIGH to LOW
void isr () {
delay(4); // delay for Debouncing
if (digitalRead(PinCLK))
rotationdirection= digitalRead(PinDT);
else
rotationdirection= !digitalRead(PinDT);
TurnDetected = true;
}

void setup () {

pinMode(PinCLK,INPUT);
pinMode(PinDT,INPUT);
pinMode(PinSW,INPUT);
digitalWrite(PinSW, HIGH); // Pull-Up resistor for switch
attachInterrupt (0,isr,FALLING); // interrupt 0 always connected to pin 2 on Arduino UNO
}

void loop () {
small_stepper.setSpeed(700); //Max seems to be 700
if (!(digitalRead(PinSW))) { // check if button is pressed
if (RotaryPosition == 0) { // check if button was already pressed
} else {
small_stepper.step(-(RotaryPosition*50));
RotaryPosition=0; // Reset position to ZERO
}
}

// Runs if rotation was detected
if (TurnDetected) {
PrevPosition = RotaryPosition; // Save previous position in variable
if (rotationdirection) {
RotaryPosition=RotaryPosition-1;} // decrase Position by 1
else {
RotaryPosition=RotaryPosition+1;} // increase Position by 1

TurnDetected = false;  // do NOT repeat IF loop until new rotation detected

// Which direction to move Stepper motor
if ((PrevPosition + 1) == RotaryPosition) { // Move motor CW
  StepsToTake=50; 
  small_stepper.step(StepsToTake);
}

if ((RotaryPosition + 1) == PrevPosition) { // Move motor CCW
  StepsToTake=-50;
  small_stepper.step(StepsToTake);
}

}
digitalWrite(8, LOW);
digitalWrite(9, LOW);
digitalWrite(10, LOW);
digitalWrite(11, LOW);
}