int pin_nums[8] = {2, 3, 4, 5, 6, 7, 8, 9};


void setup() {
  Serial.begin(9600);
  for(int i = 0; i <= 7; i++) {
    pinMode(pin_nums[i], OUTPUT);
  }
 // bin_led_pattern(0b11110000);
    bin_led_pattern(0xF0);
}

void loop() {
  /*
  for(int i = 0; i <= 7; i++) {
    digitalWrite(pin_nums[i], HIGH);
    delay(200);
    digitalWrite(pin_nums[i], LOW);
  }

  for(int i = 7; i >= 0; i--) {
    digitalWrite(pin_nums[i], HIGH);
    delay(200);
    digitalWrite(pin_nums[i], LOW);
  }
  */

  

}

void bin_led_pattern(byte pattern) {
  Serial.println("Byte pattern: ");
  Serial.print(pattern,BIN);
  for(int i = 0; i < 8; i++) {
    digitalWrite(pin_nums[i],bitRead(pattern,i));
  }

}