float vpt;
float maksbit;
int maksvolt = 204;

void setup() {
  pinMode(A0, INPUT);
  pinMode(13, OUTPUT);
  Serial.begin(9600);
}

void loop() { 
  int nilaipotensio = analogRead(A0);
  maksbit = nilaipotensio;
  vpt = maksbit/maksvolt;
  //jika tegangan >2.5 maka lampu hidup
  if (vpt>=2.5){
    digitalWrite(13,HIGH);
  } else {
    digitalWrite(13, LOW);
  }

  Serial.print("nilai pin A0 =");
  Serial.print(nilaipotensio);


  Serial.print("nilai volt =");
  Serial.print(vpt);

  delay(1000);
}