#include <SPI.h>

const int LATCH_PIN = 8;

byte var55 = 0b01010101;
byte varAA = 0b10101010;

void setup() {
  SPI.begin();
  pinMode(LATCH_PIN, OUTPUT);
}

void loop() {
  digitalWrite(LATCH_PIN, LOW);
  SPI.transfer(var55);
  digitalWrite(LATCH_PIN, HIGH);

  delay(1000);

  digitalWrite(LATCH_PIN, LOW);
  SPI.transfer(varAA);
  digitalWrite(LATCH_PIN, HIGH);

  delay(1000);
}