int trig_pin=9;
int echo_pin=8;

float dura_ms, dist_cm;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(trig_pin, OUTPUT);
pinMode(echo_pin, INPUT);

}

void loop() {
digitalWrite(trig_pin, HIGH);
delayMicroseconds((10));
digitalWrite(trig_pin, LOW);
dura_ms=pulseIn(echo_pin,HIGH);
dist_cm=0,017*dura_ms+2;
Serial.println("The distance: ");
Serial.println(dist_cm);
delay(1000);

}