const int sensorPin = A0;
const float baselineTemp = 20.0;
void setup() {
  Serial.begin(9600); // Open a serial port
  for(int pinNumber = 2; pinNumber<5; pinNumber++){
    pinMode(pinNumber, OUTPUT);
    digitalWrite(pinNumber, LOW);
  }
}
void loop(){
  int sensorVal = analogRead(sensorPin);
  Serial.print("Sensor Value: ");
  Serial.print(sensorVal);
  // Convert the ADC reading to voltage
  float voltage = (sensorVal/1024.0) * 5.0;
  Serial.print(", Volts: ");
  Serial.print(voltage);
  Serial.print(". degrees C: ");
  // Converts voltage to temperature in Celcius
  float temperature = (voltage - .5) * 100;
  Serial.print(temperature);
  if(temperature < baselineTemp){
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }else if(temperature >= baselineTemp+2 && temperature < baselineTemp+4) {
    digitalWrite(2, HIGH);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }else if(temperature >= baselineTemp+4 && temperature < baselineTemp+6){
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, LOW);
  }else if(temperature >= baselineTemp+6){
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
  }
  delay(1);
}