Here is the entire code:
const int sensorPin = A0;
const float baselineTemp = 20.0;
void setup (){
Serial.begin(9600); //open 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:");
// convert the voltage to temerpature in degrees
float temperature = (voltage - .5) * 100;
Serial.println(temperature);
if(temperature < baselineTemp){
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
}else if(temperature >= baselineTemp+2 &&
temperature < baseline+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);
}