#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
const byte trigEchoTekPin = 10;  
unsigned long sure;
const byte led1=2,led2=3,led3=4;
 
LiquidCrystal_I2C lcd(0x27,20,4);

void setup() {
 lcd.init();
 lcd.backlight();  
lcd.print("Mesafe");
Serial.begin(9600);
pinMode(led1,OUTPUT);
pinMode(led2,OUTPUT);
pinMode(led3,OUTPUT);
}
void loop() {
pinMode(trigEchoTekPin, OUTPUT);  
delayMicroseconds(10);
digitalWrite(trigEchoTekPin, 1);
delayMicroseconds(10);
pinMode(trigEchoTekPin, INPUT);  
sure = pulseInLong(trigEchoTekPin, 1);  
lcd.setCursor(0, 1);
lcd.print((0.0343 * sure) / 2);  
lcd.setCursor(10, 1);
lcd.print(" cm");
if( 0.0343 * sure>50)
{
   Serial.println("uzaklik");
  digitalWrite(led2,0);
  digitalWrite(led1,0);
  digitalWrite(led3,0);
}
else if( 0.0343 * sure>40 && 0.0343 * sure<=50 ){
  Serial.println("1");
  digitalWrite(led1,1);
  digitalWrite(led2,0);
  digitalWrite(led3,0);
}
else if( 0.0343 * sure>30 && 0.0343 * sure<=40){
  Serial.println("2");
  digitalWrite(led2,1);
  digitalWrite(led1,0);
  digitalWrite(led3,0);
}
else if( 0.0343 * sure>20 && 0.0343 * sure<=30){
  Serial.println("3");
   digitalWrite(led2,0);
  digitalWrite(led1,0);
  digitalWrite(led3,1);
}
else if ( 0.0343 * sure>10 && 0.0343 * sure<=20){
  Serial.println("4");
  digitalWrite(led2,0);
  digitalWrite(led1,1);
  digitalWrite(led3,1);
}
else{
Serial.println("5");
digitalWrite(led2,1);
digitalWrite(led1,1);
digitalWrite(led3,1);
}
}