const int TRIG_PIN = 26;
const int ECHO_PIN = 25;

int getDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(5);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  long cm = (duration / 2) * 0.0341;  // multiply by 0.0343 or divide by 29.1
  //long inches = (duration / 2) * 0.0135; // multiply by 0.0135 or divide by 74
  return cm;
}

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!\n");
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  static int oldDistance = -1;  // ensures first print

  int distance = getDistance();
  // if the distance changes more than 1 cm print new distance
  if (distance > oldDistance + 1 || distance < oldDistance - 1)  {
    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm.");
    oldDistance = distance;
  }
  delay(500); // slow the loop a little
}