void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(14, INPUT);
  pinMode(26, OUTPUT);

}

void loop() {
  digitalWrite(26, HIGH);
  delay(1000);
  digitalWrite(26, LOW);
  float dur=pulseIn(14,HIGH);
  int dis=dur*0.034/2;
  Serial.println(dis); 
}