#include <Servo.h>

//Pin connected to ST_CP of 74HC595
int latchPin = 8;
//Pin connected to SH_CP of 74HC595
int clockPin = 12;
////Pin connected to DS of 74HC595
int dataPin = 11;

int dlay = 20;
//holders for infromation you're going to pass to shifting function
byte data;
byte dataArray[10];

Servo myservo;

int val;

void setup() {
  //set pins to output because they are addressed in the main loop
  pinMode(latchPin, OUTPUT);
  Serial.begin(9600);
  myservo.attach(9);

}

  int rotNum = 0;
  int encoder0PinALast = LOW;
  int n = LOW;

void loop() {


  n = digitalRead(4);
  if ((encoder0PinALast == LOW) && (n == HIGH)) {
    if (digitalRead(7) == LOW) {
      rotNum--;
      delay(dlay);
    } else {
      rotNum++;
      delay(dlay);
    }
  }
  encoder0PinALast = n;
  if (rotNum > 99) {
    rotNum = 0;
  }
  if (rotNum < 0) {
    rotNum = 99;
  }
  shiftNumber(rotNum);
  val = rotNum;            // reads the value of the potentiometer (value between 0 and 1023)
  val = map(val, 0, 99, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
  myservo.write(val);                  // sets the servo position according to the scaled value
}


void shiftNumber(int myInput) {
  //ground latchPin and hold low for as long as you are transmitting
  digitalWrite(latchPin, 0);
  //move 'em out

  int b = myInput % 10;
  int a = (myInput - b) / 10;
  int temp = a * 16 + b;
  shiftOut(dataPin, clockPin, temp);
  //return the latch pin high to signal chip that it
  //no longer needs to listen for information
  digitalWrite(latchPin, 1);
}




// the heart of the program
void shiftOut(int myDataPin, int myClockPin, byte myDataOut) {
  // This shifts 8 bits out MSB first,
  //on the rising edge of the clock,
  //clock idles low

  //internal function setup
  int i = 0;
  int pinState;
  pinMode(myClockPin, OUTPUT);
  pinMode(myDataPin, OUTPUT);

  //clear everything out just in case to
  //prepare shift register for bit shifting
  digitalWrite(myDataPin, 0);
  digitalWrite(myClockPin, 0);

  //for each bit in the byte myDataOut�
  //NOTICE THAT WE ARE COUNTING DOWN in our for loop
  //This means that %00000001 or "1" will go through such
  //that it will be pin Q0 that lights.
  for (i = 7; i >= 0; i--)  {
    digitalWrite(myClockPin, 0);

    //if the value passed to myDataOut and a bitmask result
    // true then... so if we are at i=6 and our value is
    // %11010100 it would the code compares it to %01000000
    // and proceeds to set pinState to 1.
    if ( myDataOut & (1 << i) ) {
      pinState = 1;
    }
    else {
      pinState = 0;
    }

    //Sets the pin to HIGH or LOW depending on pinState
    digitalWrite(myDataPin, pinState);
    //register shifts bits on upstroke of clock pin
    digitalWrite(myClockPin, 1);
    //zero the data pin after shift to prevent bleed through
    digitalWrite(myDataPin, 0);
  }

  //stop shifting
  digitalWrite(myClockPin, 0);
}