#include <Wire.h>
#include <DHT.h>
#include <LiquidCrystal_I2C.h>

// declare pin
# define trigPin 9
# define echoPin 10
// declare variable
unsigned long travelTime;
unsigned long duration;
unsigned long distance;



void setup()
{
Serial.begin(9600);
pinMode(trigPin,OUTPUT);
pinMode(echoPin,INPUT);
}
void loop()
{
digitalWrite(trigPin,LOW); // no output
delay(2);
digitalWrite(trigPin,HIGH); // generate output
delay(10);
digitalWrite(trigPin,LOW); // no output
travelTime=pulseIn(echoPin,HIGH);
duration = travelTime/2;
distance = duration*0.0344;
Serial.print("Distance= ");
Serial.println(distance);
delay(2000);
}