# Arduino code
```
const int hot = 20; //set hot parameter
const int cold = 10; //set cold parameter
void setup() {
pinMode(A2, INPUT); //sensor
pinMode(2, OUTPUT); //orange
pinMode(3, OUTPUT); //green
pinMode(4, OUTPUT); //red
Serial.begin(9600);
}
void loop() {
int sensor = analogRead(A2);
float voltage = (sensor / 1024.0) * 5.0;
float tempC = (voltage - .5) * 100;
// float tempF = (tempC * 1.8) + 32;
// Serial.print("temp: ");
// Serial.print(tempF);
if (cold > 0 && tempC <= cold) { //cold
digitalWrite(3, HIGH);
digitalWrite(2, LOW);
digitalWrite(4, LOW);
Serial.println(" It's Green.");
}
else if (tempC > cold && tempC < hot) {
digitalWrite(2, HIGH);
digitalWrite(3, LOW);
digitalWrite(4, LOW);
Serial.println(" It's Orange.");
}
else if (tempC >= hot) {
digitalWrite(2, LOW);
digitalWrite(3, LOW);
digitalWrite(4, HIGH);
Serial.println(" It's Red.");
}
delay(10);
}
```