const int echoPin = 2;
const int trigPin = 3;
long duration;
int distance;
void setup() {
 pinMode(trigPin, OUTPUT); 
 pinMode(echoPin, INPUT); 
 Serial.begin(9600);
}
void loop() {
 digitalWrite(trigPin, LOW); 
 delayMicroseconds(2);
 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigPin, LOW);
 duration = pulseIn(echoPin, HIGH);
 distance = duration * 0.034 / 2;
 Serial.print("Distance: ");
 Serial.println(distance);
 delay(1000);
}