int blue = 12;
int red= 6;
int green =10;

void setup(){
  pinMode(blue,OUTPUT);
  pinMode(blue,OUTPUT);
  pinMode(blue,OUTPUT);
  Serial.begin(9600);
}
void loop(){
  int val=analogRead(A0);
  float volt= val*5.0/1023.0;
  //0.01T+0.5 =V
  float temp= (volt-0.5)*100.0;
  if (temp<20){
    digitalWrite(blue,HIGH);
    digitalWrite(green,LOW);
    digitalWrite(red,LOW);
  }
  else if (temp<30){
    digitalWrite(blue,LOW);
    digitalWrite(green,HIGH);
    digitalWrite(red,LOW);
  }
  else{
    digitalWrite(blue,LOW);
    digitalWrite(green,LOW);
    digitalWrite(red,HIGH);
  }
  Serial.print("Temperature is");
  Serial.println( temp);
  
}