void setup() {
  //Serial.begin(9600);
  beginParallel();
  
  for(int i = 0; i <= 255; i++){
    sendParallel(i);
    delay(10);
  }

}

void loop() {

}

void beginParallel(){
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);

  pinMode(13, OUTPUT);
}

void sendParallel(byte dataIn){
  digitalWrite(13, HIGH);
  for(int i = 7; i >= 0; --i){
    bool bitValue = (dataIn & (1 << i)) != 0;
    if(bitValue == true){
      digitalWrite(i+2, HIGH);
      //Serial.println("1");
    }
    if(bitValue == false){
      digitalWrite(i+2, LOW);
      //Serial.println("0");
    }
  }
  digitalWrite(13, LOW);
}