 #include <SPI.h>
 #include <MFRC522.h>
 
-#define RST_PIN		9		//
+#define RST_PIN		2		//
 #define SS_PIN		10		//
 
 MFRC522 mfrc522(SS_PIN, RST_PIN);	// Create MFRC522 instance

void updateDisplay() {
  lcd.clear();
  if (state == LOCKED) {
    lcd.print("You shall not pass! ");
    lcd.setCursor(0, 1);
    lcd.print("                    ");
  } else if (state == SEMI_LOCKED) {
    lcd.print("It's open...        ");
    lcd.setCursor(0, 1);
    lcd.print("Press E to enter :)");
  } else if (state == PIN_ENTRY) {
    lcd.print("Enter PIN & press P ");
    lcd.setCursor(0, 1);
    for (int i = 0; i < buffer.length(); i++) {
      lcd.print("*");
    }
  } else if (state == WAIT_FOR_UNLOCK) {
    lcd.print("Waiting for         ");
    lcd.setCursor(0, 1);
    lcd.print("       confirmation ");
  } else if (state == INVALID_PIN) {
    lcd.print("  > Invalid PIN <   ");
    lcd.setCursor(0, 1);
    lcd.print("> Please try again <");
  } else if (state == UNLOCKED) {
    lcd.print("It's open...        ");
    lcd.setCursor(0, 1);
    lcd.print("Just come on in! =) ");
  }
}


 *             Reader/PCD   Uno           Mega      Nano v3
 * Signal      Pin          Pin           Pin       Pin
 * ------------------------------------------------------------
 * RST/Reset   RST          2             
 * SPI SS      SDA(SS)      10            53        D10
 * SPI MOSI    MOSI         11 / ICSP-4   51        D11
 * SPI MISO    MISO         12 / ICSP-1   50        D12
