// ---------------------------------------------------------------- //
// Arduino Ultrasoninc Sensor HC-SR04
// Re-writed by Arbi Abdul Jabbaar
// Using Arduino IDE 1.8.7
// Using HC-SR04 Module
// Tested on 17 September 2019
// ---------------------------------------------------------------- //
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2);

#define nada 262
#define nada2 349
#define echoPin 2 // attach pin D2 Arduino to pin Echo of HC-SR04
#define trigPin 3 //attach pin D3 Arduino to pin Trig of HC-SR04

// defines variables
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
int l1=8;
int buzzer=4;
void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
  Serial.println("Ultrasonic Sensor HC-SR04 Test"); // print some text in Serial Monitor
  Serial.println("with Arduino UNO R3");
  pinMode(l1, OUTPUT);
  lcd.init();
  lcd.backlight();
}
void loop() {
  // Clears the trigPin condition
lcd.setCursor(0,0);
lcd.print("jarak : ");
lcd.setCursor(0,1);
lcd.print("ket  :");
lcd.setCursor(7,0);
lcd.print(distance);
lcd.setCursor(10,0);
lcd.print("cm");


  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.034/ 2; // Speed of sound wave divided by 2 (go and back)
  // Displays the distance on the Serial Monitor
  Serial.print("Distance:");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance <100){
    digitalWrite(l1, HIGH);
    tone(buzzer, nada);
    delay(100);
    tone(buzzer, nada2);
    delay(100);
    lcd.setCursor(7,1);
    lcd.print("Dekat");
    
  }
  else {
    digitalWrite(l1, LOW);
    noTone(buzzer);
    lcd.setCursor(7,1);
    lcd.print("Jauh ");
}
}