#include "SPI.h"
  int pinLatch = 4 ;
  byte data = 1;
  int step = 1;
void nextStep(){
  if(step >= 8){
        step = 0;
        data = 0;
  }
  else {
        step++;
        data = (data <<= 1) | 1;
  }
  }
void setup() {
  // put your setup code here, to run once:
        pinMode(pinLatch, OUTPUT);
        SPI.begin();
        SPI.setBitOrder(MSBFIRST);
} 

void loop() {
        digitalWrite(pinLatch , LOW);
        SPI.transfer(data);
        digitalWrite(pinLatch, HIGH);
        delay(500);
        data = (data << 1) | 1;
        nextStep();
}