const int dataPin = 11;  // DS on 74HC595
const int latchPin = 12; // ST_CP on 74HC595
const int clockPin = 13; // SH_CP on 74HC595

void setup() {
  // Set pins to output mode
  pinMode(dataPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
}

void loop() {
  // Count from 0 to 255 (covers all combinations of 8 bits)
  for (int number = 0; number <= 255; number++) {
    // Pull the latch LOW to start sending data
    digitalWrite(latchPin, LOW);
    // Shift out the bits:
    shiftOut(dataPin, clockPin, MSBFIRST, number);
    // Once all bits are sent, set latch HIGH to send data to storage register
    digitalWrite(latchPin, HIGH);
    // Delay for a bit so we can see the change
    delay(500);
  }
}