#include <LiquidCrystal.h>
LiquidCrystal lcd(2,3,4,5,6,7);

int trig=9;
int echo=8;

void setup()
{
pinMode(trig,OUTPUT);
pinMode(echo,INPUT);

lcd.begin(16, 2);
lcd.print("HC-SR04");
}

void loop()
{
long dur;
float cm;

digitalWrite(trig,LOW);
delayMicroseconds(2);
digitalWrite(trig,HIGH);
delayMicroseconds(10);
digitalWrite(trig,LOW);
delayMicroseconds(2);

dur=pulseIn(echo,HIGH);
cm=micro2cm(dur);

lcd.setCursor(0, 1);
lcd.print("Distance:");
lcd.print(cm);
delay(1000);
}

float micro2cm(long microsec)
{
return (0.034*microsec/2);
}