const int redBlub=8;
const int ntc=A0;
void setup() {
  Serial.begin(9600);
  pinMode(redBlub, OUTPUT);

}
void loop() {
  //Read the values from pin A0 where Temperature Sensor is connected
  int analogValue=analogRead(ntc);
  //Called user defined Function
  int temp= checkTemp(analogValue);
  Serial.print("Temperature is ");
  Serial.print(temp);
  Serial.println("^C");
  //Called user defined Function
  onOffBulb(temp);
  delay(5000);
}
//In this function we convert the values to temperature 
//that are come from sensor
int checkTemp(double analogValue){
  int resistance=(1000.0/((1023.0/analogValue)-1.0));
  int temp=(1.0/((log(resistance/10000.0)/3950.0)+(1.0/298.15)))-273.15;
  return temp;
}

//In this function, On Off bulb wrt to temperature
void onOffBulb(double temp){
  if(temp>500){
    digitalWrite(redBlub,HIGH);
  }
  else{
    digitalWrite(redBlub,LOW);
  }
}