#include <LiquidCrystal_I2C.h>
#define  red 3
#define green 2
#define echoPin 7
#define trigPin 8
LiquidCrystal_I2C lcd(0x27,16,2); 
long duration;
int distance;

void setup()
{
  pinMode (trigPin,OUTPUT);
  pinMode (echoPin,INPUT);
  pinMode (red,OUTPUT);
  pinMode (green,OUTPUT);
  lcd.init();  
  lcd.init();
  lcd.backlight();
  lcd.setCursor(1,0);
  Serial.begin(9600); 
}
void loop (){
   digitalWrite (trigPin,0);
   delayMicroseconds (2);
   digitalWrite (trigPin,1);
   delayMicroseconds (10);
   digitalWrite (trigPin,0);
   duration = pulseIn (echoPin,1);
   distance = duration * 0.034 / 2;
   lcd.print("distance:-");
   lcd.setCursor(1,15);
   lcd.print(distance);
   Serial.print(" Distance:") ;
   Serial.print (distance);
   Serial.println("cm");
   delay(2000);
   lcd.clear();
   if (distance >0 && distance <=150) {
      digitalWrite (green,1);
      delay (1000);
      digitalWrite (green,0);

   }
else   
 {
  digitalWrite (red,1);
        delay (1000);
  digitalWrite (red,0);

}
 }