#include <Servo.h>
#include <LiquidCrystal_I2C.h>
#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position
unsigned int count1;
#define ECHO_PIN 2
#define TRIG_PIN 3

float readDistanceCM(void);
void opend(void);

void setup() {
  Serial.begin(9600);
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(0);
  lcd.init();
  lcd.backlight();
  
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Print something
  lcd.setCursor(0, 0);
  lcd.print("count : ");

}
void loop() {
  // for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
  //   // in steps of 1 degree
  //   myservo.write(pos);              // tell servo to go to position in variable 'pos'
  //   delay(15);                       // waits 15ms for the servo to reach the position
  // }
  // for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
  //   myservo.write(pos);              // tell servo to go to position in variable 'pos'
  //   delay(15);                       // waits 15ms for the servo to reach the position
  // }

  lcd.setCursor(8,0);
  lcd.print(count1);
  int a1 = readDistanceCM();
  Serial.print("distance : ");
  Serial.println(a1);
  if(a1 >120){
    opend();
    count1++;
    Serial.println("opendoor << ");
  }
  

}

// delay(15) เพื่อ : รอ 15 ms สำหรับ servo ไปยังตำแหน่งเป้าหมาย

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}
void opend(void){
  myservo.write(0);
  delay(2000);
  myservo.write(180);
  delay(2000);
  myservo.write(0);
  //delay(2000);
}