#include <LiquidCrystal.h>
  #include <Servo.h>
  #include <EEPROM.h>

  // initialize the library with the numbers of the interface pins
  Servo myepicservo;
  const int echoPin = 49;
  const int trigPin = 51;
  int targAngle=0;
  LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
  float duration; 
  float cmeters; // distance in centimeters
  int opendist;
  bool domove = true; // queues a move
  bool open = true; // reflects state of door
  String tempS = " "; // temp string to take in serial data

  void setup() {
    pinMode(echoPin, INPUT);
    pinMode(trigPin, OUTPUT);
    myepicservo.attach(53);
    

    // set up the LCD's number of columns and rows:
    lcd.begin(16, 2);
    // Start Serial monitor
    Serial.begin(9600);

    // get value from EEPROM
    opendist = EEPROM.read(0);
    if (opendist == 0xFFFF){ // if EEPROM empty fill with default value
      opendist = 100;
    }
  }

  void loop() {
    Serial.println(opendist);
    if (Serial.available() > 0){
      tempS = Serial.readStringUntil('\n');

      if (opendist != tempS.toInt()){ // update if value differs
        opendist = tempS.toInt();

        if (EEPROM.read(0) != opendist){ // puts value in EEPROM
          EEPROM.update(0, opendist);
        }
      }
    }

    delayMicroseconds(38); //gap time
    digitalWrite(trigPin, HIGH);

    delayMicroseconds(10); //pulse time
    digitalWrite(trigPin, LOW);

    duration = pulseIn(echoPin, HIGH); //listen
    

    cmeters = (0.0343 * duration)/2; // (Speed x Time) / 2 
    lcd.setCursor(0,1);
    lcd.print(String(cmeters) + "cm ");

    //checks if a move is avalible
    if (open == true && cmeters > opendist){
      domove = true;
      open = false;
    }
    if (open == false && cmeters <= opendist){
      domove = true;
      open = true;
    }

    // moves door if move is avalible
    if (domove == true){
      lcd.setCursor(0,0);

      if (open == true){ // Open door
        lcd.print("Door Open       ");
        myepicservo.write(180);
      }
      if (open == false){ // Close door
        lcd.print("Door Closed     ");
        myepicservo.write(0);
      }

      domove = false; // set move to false
    }
  }