#define lampupin 
const int lampupin = 7; //letak const bisa sebelum atau sesudah tipe data
void setup() {
  pinMode(lampupin, OUTPUT);
  Serial.begin(9600);

}

void loop() {
  digitalWrite(lampupin, HIGH);
  Serial.print("LAMPU ON\n");
  delay(1500);
  digitalWrite(lampupin, LOW);
  Serial.println("LAMPU OFF");
  delay(1000);
}