#include <SPI.h>
#include <MFRC522.h>
#include <Servo.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C screen (0x3f, 16, 2);
#define SS_PIN 10
#define RST_PIN 9
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
Servo Tahm;

const int trigPin = 6;
const int echoPin = 7;
long duration;
int distanceCm, distanceInch;




void setup()
{
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  screen.begin();
  screen.setBacklight((uint8_t)1);
  Serial.begin(9600);   // Initiate a serial communication
  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
  Serial.println("Searching for a card.");
  Serial.println();
  Tahm.attach (3);
  Tahm.write (179);
  msg();
}
void msg() {
  screen.clear();
  screen.print("  where ");
  screen.setCursor (0,1);
  screen.print ("    ya at");
}
void loop()
{
  // Look for new cards
  if ( ! mfrc522.PICC_IsNewCardPresent())
  {
    return;
  }
  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial())
  {
    return;
  }
  //Show UID on serial monitor
  Serial.print("UID tag :");
  String content= "";
  byte letter;
  for (byte i = 0; i < mfrc522.uid.size; i++)
  {
     Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
     Serial.print(mfrc522.uid.uidByte[i], HEX);
     content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
     content.concat(String(mfrc522.uid.uidByte[i], HEX));
  }
  Serial.println();
  Serial.print("Message : ");
  content.toUpperCase();
  if (content.substring(1) == "2E AE DD 89") //change here the UID of the card/cards that you want to give access
  {
    Serial.println("ye come on in");
    Serial.println();
    screen.clear();
    screen.print (" u good.");
    Tahm.write (0);
    delay (5000);
    Tahm.write (179);
    msg();
  }

 else   {
    Serial.println("Adios");
    screen.clear();
    screen.print (" authorities are ");
    screen.setCursor (0,1);
  screen.print ("on their way");
    delay(5000);
    msg();
  }
}