Cafeteira arduino

cafeteira.c

#define RED 33
#define GREEN 32

#define echoPin 40 
#define trigPin 41 

int maximumRange = 200; 
int minimumRange = 50; 
long duration, distance; 

void setup()
{
  Serial.begin (9600);
  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
 
   digitalWrite(trigPin, LOW); 
   delayMicroseconds(2); 
  
   digitalWrite(trigPin, HIGH);
   delayMicroseconds(10); 
   
   digitalWrite(trigPin, LOW);
   duration = pulseIn(echoPin, HIGH);
   
  
   distance = duration/58.2;
   
   if (distance >= maximumRange || distance <= minimumRange){
    
     Serial.println("-1");
     digitalWrite(GREEN, HIGH);
     digitalWrite(RED, LOW);
   }
   else {
    
     Serial.println(distance);
     digitalWrite(RED, HIGH); 
     digitalWrite(GREEN, LOW);
   }
   
   
   delay(50);
}