const float BETA = 3950; 
int brunzidor = A5;

void setup() {
  Serial.begin(9600); 
  pinMode(8, OUTPUT); 
  pinMode(4, OUTPUT); 
  pinMode(2, OUTPUT); 
  pinMode(brunzidor, OUTPUT);
}

void loop() { 
  int analogValue = analogRead(A0); 
  float celsius = 1 / (log(1 / (1023. / analogValue -1)) / BETA + 1.0 / 298.15) - 273.15; 
  Serial.print("temperatura: "); 
  Serial.print(celsius);
  Serial.println(" grados celsius ");
    
    if(celsius > 45){ 
      digitalWrite(8, LOW); 
      digitalWrite(2, HIGH); 
      delay(100); 
      digitalWrite(2, LOW);
      Serial.println("⚠ temperatura perjudicial para el sistema ⚠");
      for (int i=1024; i<=1024; i=i+100)
      tone (brunzidor, i, 100);
      delay (200);
      noTone (brunzidor);
}
    if(celsius < -23.99)
    if(celsius > -25.00)
    {
      Serial.println("¡¡¡Temperatura excesivamente BAJA!!!");
}
    if(celsius < 45){ 
      digitalWrite(8, HIGH);
      digitalWrite(2, LOW);
}
      digitalWrite(4, HIGH);
      delay(1000); 
      digitalWrite(4, LOW); 
      delay(1000); 
}