int clearPin = 5; //Arduino pin 5 connected to Pin 10, SRCLR(Clear/Reset) of 74HC595
int serialData = 6;  //Arduino pin 6 connected to Pin 14, SER(serial input) of 74HC595
int shiftClock = 7;  //Arduino pin 7 connected to Pin 11, SRCLK(shift clock) of 74HC595
int latchClock = 8;  //Arduino pin 8 connected to Pin 12, RCLK(storage/latch clock) of 74HC595 ]


void setup() {   //runs once at startup
   //set pins to output so you can control the shift register
  pinMode(clearPin, OUTPUT);
  pinMode(shiftClock, OUTPUT);
  pinMode(latchClock, OUTPUT);
  pinMode(serialData, OUTPUT);


  digitalWrite(clearPin, LOW); //Pin is active-low, this clears the shift register
  digitalWrite(clearPin, HIGH); //Clear pin is inactive
}


void loop() {    //runs and loops continuously
    for (int shiftCount = 0; shiftCount < 256;shiftCount++) {  
          // count from 0 to 255 and display the number on the LEDs
  
  digitalWrite(latchClock, LOW);    
          // take the latchClock low so 
          // the LEDs don't change while you're sending in bits:


   shiftOut(serialData, shiftClock, MSBFIRST, shiftCount);      // shift out the bits
   digitalWrite(latchClock, HIGH);     //take the latch pin high so the LEDs will light up
   delay(500);     // pause before next value
  }
}