void setup() {
  // put your setup code here, to run once:
  pinMode(A0, INPUT);
  pinMode(2, OUTPUT);
  pinMode(13, OUTPUT);

  Serial.begin(115200);
  Serial.println("Hello !");
}

int setTemperature = 18;
int hysteresis = 1;

int nextLoop_ms = 0;
int period_ms = 100;

void loop() {
  if (millis() > nextLoop_ms) {
    nextLoop_ms += period_ms;

    // Read temperature: convert the 0-1023 sensor reading to 20-50°C temperature range.
    digitalWrite(13, HIGH);
    float temperature = map((float)analogRead(A0), 0., 1023, -20, 50);
    float command = 0.0;

    if (temperature < setTemperature) {
      // It's cold: turn on the heater
      digitalWrite(2, HIGH);
      command = 1.0;
    } else {
      // It's warm: turn off the heater
      digitalWrite(2, LOW);
    }

    Serial.print(temperature);
    Serial.print(", ");
    Serial.print(command);
    Serial.println();
    
    digitalWrite(13, LOW);
  }

}