const int tempPin = A0;
const int ledPin = D13;

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

void loop() {
while(1)
{
  int adcValue = analogRead(tempPin);

  Serial.print("ADC: ");
  Serial.println(adcValue);

  if (adcValue < 512) {   // higher temperature
    digitalWrite(ledPin, HIGH);
  } 
  else {
    digitalWrite(ledPin, LOW);
  }

  delay(500);
}
}