const int trig = 4;
const int echo = 2;

long duration;//
long distance;


void setup() {

  Serial.begin(115200);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
}

void loop() {
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(15);
  digitalWrite(trig, LOW);

  duration = pulseIn(echo, HIGH);
  distance = (duration * 0.034/2) + 1;
  Serial.println("duration" + String(distance));
  delay(1000);
}