void setup() {
  Serial.begin(115200);
  pinMode(12, OUTPUT);
}

void loop() {
  int x=analogRead(13);
  Serial.println(x);
  if(x<=500)
  {
    digitalWrite(12,LOW);
    Serial.println("OFF");
  }
  else
  {
    digitalWrite(12,HIGH);
    Serial.println("ON");
  }
}