#define latchPin 10
#define clockPin 11
#define dataPin 12

void setup() {
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
}

void loop() {
  for (int i = 0; i < 256; i++) {
    digitalWrite(latchPin, LOW);
    shiftOut(dataPin, clockPin, MSBFIRST, i);
    digitalWrite(latchPin, HIGH);
    delay(500);
  }
}