#define Led 9
#define btn 8
int nilai = 0;

void setup() {
  Serial.begin(9600);
  pinMode(Led, OUTPUT);
  pinMode(btn, INPUT);

}

void loop() {
  nilai = digitalRead(btn);
  Serial.print("nilai =");
  Serial.println(nilai);
  if(nilai == 1){
    digitalWrite(Led, HIGH);
  }else{
    digitalWrite(Led, LOW);
  }

}