const int tempPin = A0;       // Temperature Sensor connected to A0
const int heaterPin = 13;     // Heater simulated with LED on pin 13

const float lowerThreshold = 20.0; // Turn ON heater
const float upperThreshold = 25.0; // Turn OFF heater

bool heaterOn = false;
const float BETA = 3950; 

void setup() {
  pinMode(heaterPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(tempPin);
 float temperature = 1 / (log(1 / (1023. / sensorValue - 1)) / BETA + 1.0 / 298.15) - 273.15;

   
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" C ");

  if (temperature < lowerThreshold && !heaterOn) {
    digitalWrite(heaterPin, HIGH);
    heaterOn = true;
    Serial.println("Heater ON");
  } else if (temperature > upperThreshold && heaterOn) {
    digitalWrite(heaterPin, LOW);
    heaterOn = false;
    Serial.println("Heater OFF");
  }

  delay(1000);  // Delay for 1 second
}