Sensor de distancia

// Los pines a donde se conectará el sensor
int trig = 7; //23
int echo = 6; //24
int dist = 0;

int distancia() {
int centimetros = 1;

while (digitalRead(echo) == LOW) {
digitalWrite(trig, HIGH);
delayMicroseconds(50);
digitalWrite(trig, LOW);
}
while (digitalRead(echo) == HIGH) {
centimetros++;
delayMicroseconds(27);
}
delay(50);
return centimetros;
}

void setup() {
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
lcd.pins(0, 1, 2, 3, 4, 5, 0, 0, 0, 0); // RS, E, D4 ~ D8   
lcd.begin(16, 2);
}

void loop() {
dist = distancia();
lcd.home();
lcd.print("Distancia: ");
lcd.printNumber(dist, 10);
lcd.print("cm.");
delay(20);
}