float vpt;
int bitcutter = 204;

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

void loop() {
  float nilaipot = analogRead(A0);
  vpt = nilaipot/bitcutter;

  if(vpt > 2.5) {
    digitalWrite(13, HIGH);
  }
  else {
    digitalWrite(13, LOW);
  }

  Serial.print(" Nilai pin A0 = ");
  Serial.println(nilaipot);
  Serial.print("Nilai Volt = ");
  Serial.print(vpt);
}