//https://create.arduino.cc/projecthub/Junezriyaz/distance-measurement-using-arduino-ultrasonic-sensor-409169
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2);
const int trigPin = 3;
const int echoPin = 2;
const int buzzPin = 8;
const int LEDpin = 4;
long duration;
int distanceValue;
//byte Bell[] = {
  //B00100,
  //B01110,
  //B01110,
  //B01110,
  //B11111,
  //B00000,
  //B00100,
  //B00000
//};
void setup() {
  lcd.init();
  lcd.begin(16, 2); // Initializes the interface to the LCD display
  //lcd.backlight();
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzPin, OUTPUT);
  pinMode(LEDpin, OUTPUT);
  //lcd.createChar(1, Bell);
  //Serial.begin(9600);
}
void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distanceValue = (duration * 0.0340) / 2;//IN CM
  //distanceValue = (duration * 0.01330) / 2; //IN INCH
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  //Serial.println(distanceValue);
  lcd.print(distanceValue+1);//1 is used for bias correction
  lcd.print(" cm");
  lcd.noBacklight();
  //lcd.blink();
   //delay(10);
    if (distanceValue <= 50 && distanceValue >= 0) {

lcd.backlight();
lcd.setCursor(0, 1);
lcd.print("....Warnning....");
//lcd.createChar(1, Bell);
//lcd.blink();
digitalWrite(buzzPin, HIGH);
digitalWrite(LEDpin, HIGH);
delay(600);
digitalWrite(buzzPin, LOW);
digitalWrite(LEDpin, LOW);
delay(600);
} else {
digitalWrite(buzzPin, LOW);
digitalWrite(LEDpin, LOW);
lcd.noBacklight();
lcd.setCursor(0, 1);
  for (int thisChar = 0; thisChar < 14; thisChar++) {
    lcd.print(".");
    lcd.blink();
    delay(20);
  }
}
  delay(60);
}