#include <Wire.h>   
#include<LiquidCrystal_I2C.h>  
 LiquidCrystal_I2C lcd(0x27,16,2);   
 const int trigPin = 9;  
 const int echoPin = 10;  
 long duration;  
 int distanceCm, distanceInch;  

 const int REd = 2;
 const int Yellow = 0;
 const int Green = 1;
 const int button = 3;
 void setup()  
 {  
 lcd.init();  
 lcd.backlight();   
 Serial.begin(9600);   
 pinMode(trigPin, OUTPUT);  
 pinMode(echoPin, INPUT);  
 pinMode(REd, OUTPUT);
 pinMode(Yellow, OUTPUT);
 pinMode(Green , OUTPUT);
 pinMode(button, INPUT);

 }  
 void loop() {  
 digitalWrite(trigPin, LOW);  
 delay(1000);  
 digitalWrite(trigPin, HIGH);  
 delay(1000);  
 digitalWrite(trigPin, LOW);  
 duration = pulseIn(echoPin, HIGH);  
 distanceCm= duration*0.034/2;  
 distanceInch = duration*0.0133/2;  
 Serial.println("Distance: ");  
 Serial.println(distanceCm);  
 lcd.setCursor(0,0); // Sets the location at which subsequent text written to the LCD will be displayed  
 lcd.print("Distance: "); // Prints string "Distance" on the LCD  
 lcd.print(distanceCm); // Prints the distance value from the sensor  
 lcd.print(" cm ");  
 if(distanceCm < 100)
 { lcd.setCursor(0,1);
   lcd.print("Red led is On ");
   delay(500);
   digitalWrite(REd, HIGH);
 }
 else if(distanceCm>100 && distanceCm<200)
 { lcd.setCursor(0,1);
   lcd.print("Yellow led is On ");
   delay(500);
   digitalWrite(Yellow, HIGH);
 }

 else if(distanceCm>300)
 { lcd.setCursor(0,1);
   lcd.print("Green led is On ");
   delay(500);
   digitalWrite(Green, HIGH);
 }

 
 

 }