/*********
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/esp32-hc-sr04-ultrasonic-arduino/
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.
  
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*********/
#include <ESP32Servo.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

Servo myservo;
const int servoPin = 15;
const int trigPin = 5;
const int echoPin = 18;

// Define sound speed in cm/uS
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceCm;
float distanceInch;

// Initialize the LCD with the address 0x27
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Adjust the parameters (address, columns, rows) according to your LCD

void setup() {
  Serial.begin(115200); // Starts the serial communication
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  myservo.attach(servoPin);

  // Initialize the LCD
  lcd.init();
  lcd.backlight(); // Turn on the backlight
  lcd.setCursor(0, 0);
  lcd.print("Distance (cm): ");
}

void loop() {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state 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);
  
  // Calculate the distance
  distanceCm = duration * SOUND_SPEED/2;
  
  // Convert to inches
  distanceInch = distanceCm * CM_TO_INCH;

  //Jika jarak kurang dari 200 cm, gerakkan servo 90 derajat
  if (distanceCm < 200) {
    myservo.write(90);
    delay(500);  // Tunggu sebentar untuk memberikan waktu servo bergerak
  } else {
    myservo.write(0);  // Kembalikan servo ke posisi awal jika tidak ada objek dalam jarak
  }

  // Prints the distance on the LCD
  lcd.setCursor(0, 1);
  lcd.print("             "); // Clear the previous distance
  lcd.setCursor(0, 1);
  lcd.print(distanceCm);
  lcd.print(" cm");

  // Prints the distance in the Serial Monitor
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);
  Serial.print("Distance (inch): ");
  Serial.println(distanceInch);
  
  delay(1000);
}