How Shift Register works? Page https://goo.gl/GcZxCR

_31_arduSerie_sketch_01.74HC164.ino

const int clockPin = 9;
const int dataPin = 8;

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

void loop(){
  for(int i = 0; i<8; i++)
  {
    shiftOut(dataPin, clockPin, MSBFIRST, B00000001 << i);
    delay(125);//125*8 = 1 second
  }
  for (int i = 0; i<8; i++){
    shiftOut(dataPin, clockPin, MSBFIRST, B10000000 >> i);
    delay(125);//125*8 = 1 second
  }

}