int Trig = 2;
int Echo = 3;
unsigned long pulsewidth;
float distance;

void setup() {
Serial.begin(9600);
pinMode(Echo, INPUT);
pinMode(Trig, OUTPUT);
}

void loop() {
digitalWrite(Trig,HIGH);
delay(10);
digitalWrite(Trig,LOW);

pulsewidth = pulseIn(Echo, HIGH);

distance = pulsewidth/58.0;
distance = (int(distance*100.0))/100.0;

Serial.print(distance);
Serial.println("cm");
delay(100);

}