const int trigPin = 5;
const int echoPin = 18;
void setup() {
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}
void loop() {
  // Clear Trig
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Send 10uS High pulse
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Read Echo (Time in microseconds)
  long duration = pulseIn(echoPin, HIGH);
  // Calculate Distance (Speed of sound = 0.034 cm/uS)
  int distance = duration * 0.034 / 2;
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  delay(100);
}