const int trigpin=8;
const int echopin=9;
long duration;
int distance; 
void setup() {
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  Serial.begin(9600);
  // put your setup code here, to run once:

}

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);
  // put your main code here, to run repeatedly:

}