const float beta=3950;
int reading;
float v;
float temp;
int yellow=12;int green=8;int red=2;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(yellow, OUTPUT);pinMode(green, OUTPUT);
  pinMode(red, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  reading=analogRead(A4);
  v=reading*(5.0/1024.0);
temp=1/(log(1/(1023./reading-1))/beta+1.0/298.15)-273.15;
  Serial.print("The temperature is");
  Serial.print(temp);
  Serial.println("°C");
  if(temp>30) {
    Serial.println("The temperature is high");
    digitalWrite(green, LOW);
    digitalWrite(yellow, LOW);
    while (temp>30){
    digitalWrite(red, HIGH);
    delay(150);
    digitalWrite(red, LOW);
    delay(150);
    reading=analogRead(A4)
    temp=1/(log(1/(1023./reading-1))/beta+1.0/298.15)-273.15
    }
  }
  else if(temp>=25){
    Serial.println("The temperature is optimum");
    digitalWrite(red, LOW);
    digitalWrite(yellow, LOW);
    while (temp>=25 && temp<30){
    digitalWrite(green, HIGH);
    delay(120);
    digitalWrite(green, LOW);
    delay(120);
    reading=analogRead(A4)
   
    }
    ;
  }
  else{
    Serial.println("The temperature is low");
    digitalWrite(red, LOW);
    digitalWrite(green, LOW);
    digitalWrite(yellow, HIGH);
  }
  delay(1000);
  }