 
 #define SS_PIN 8
 #define RST_PIN 4
-#define RX 11
-#define TX 10
+ 
 RFID rfid(SS_PIN, RST_PIN); //create an instance rfid for the class RFID
 
 // varables to store data

  {
    if (rfid.readCardSerial())
    {
      Serial.println("Card found");
      Serial.print("Cardnumber: ");
      for (int i=0; i<=4; i++)//card value: "xyz xyz xyz xyz xyz" (15 digits maximum; 5 pairs of xyz)hence 0<=i<=4 //
      {
        RFID = rfid.serNum[i];
        cardNum += RFID; // store RFID value into string "cardNum" and concatinate it with each iteration
      }
      Serial.println(cardNum);
      cardNum.remove(0);//This is an arduino function.
  //remove the stored value after printing. else the new card value that is read
  // will be concatinated with the previous string. 
      delay(500);
    }
  }
  rfid.halt();
}


void loop()
{
 readRfid();
 printRfid();
}

void readRfid()
