int led_biru = 9; //led biru
int led_hijau = 8; //Led hijau

void setup() {
  pinMode (led_biru, OUTPUT);
  pinMode (led_hijau, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite (led_biru, HIGH);
  Serial.println("LED biru menyala, LED hijau mati");
  delay (1000);
  digitalWrite (led_biru, LOW);
  digitalWrite(led_hijau, HIGH);
  Serial.println("LED hijau menyala, LED biru mati");
  delay (1000);
  digitalWrite (led_hijau, LOW);
}