int red = 13;
int green = 12;
int blue = 11;
int tmp = 0xA0; // 0xA0

void setup()
{
    pinMode(red, OUTPUT);
    pinMode(green, OUTPUT);
    pinMode(blue, OUTPUT);
    // Serial.begin(9600);
}

void loop()
{
    int raw_data = analogRead(tmp);
    float voltage = (raw_data * 5.0) / 1024.0;
    float temperature = (voltage - 0.5) * 100;
    // Serial.println(temperature);
    if (temperature < 20)
    {
        digitalWrite(red, LOW);
        digitalWrite(green, LOW);
        digitalWrite(blue, HIGH);
    }
    else if (temperature >= 20 && temperature < 30)
    {
        digitalWrite(red, LOW);
        digitalWrite(blue, LOW);
        digitalWrite(green, HIGH);
    }
    else
    {
        digitalWrite(blue, LOW);
        digitalWrite(green, LOW);
        digitalWrite(red, HIGH);
    }
    delay(100);
}