#define pinSwitch 2
#define pinRelay 5

void setup() {
  pinMode(pinSwitch, INPUT_PULLUP);
  pinMode(pinRelay, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int nilaiSwitch = digitalRead((pinSwitch));
  if(nilaiSwitch == 0){
    digitalWrite(pinRelay, HIGH);
    Serial.println(nilaiSwitch);
  }
  else{
    digitalWrite(pinRelay, LOW);
  }
  delay(100);
}