           if(card.credits == 0){
             // ERR Beep + display "NO CREDITS"?
             //Serial.println("NO CREDITS - KNOWN CARD");
-            Serial.println("N");
+            Serial.print("N");
             // Halt PICC
             mfrc522.PICC_HaltA();
             // Return

      while(Serial.available()){Serial.read();}
      // Fetch current credit count for the vending machine, in order to know whether to withdraw or deposit
      Serial.print("C");
      //Serial.println(addr);
      // Attempt to recieve response from vending machine
      // If no response from has been recieved within a second, assume it is not powered/booted yet, stop processing
      if(Serial.readBytes(parseBuffer, sizeof(parseBuffer)) != 2){
        //Serial.print("No response - aborting.");
        return;
      }
      //Serial.println(parseBuffer[0],DEC);
      //Serial.println(parseBuffer[1],DEC);
      memcpy(&credits_in_machine,parseBuffer,sizeof(parseBuffer));
      // Zero credits in machine - done now to avoid race-conditions of people buying when saving credits
      Serial.print("Z");
      //Serial.println(credits_in_machine);

      if(credits_in_machine == 0){ // Attempt withdrawal               ## WITHDRAW
        if(addr == 65535){ // New card!
          // ERR Beep + display "NO CREDITS"?
          //Serial.println("NO CREDITS - UNKNOWN CARD");
          Serial.println("N");
          // Halt PICC
          mfrc522.PICC_HaltA();
          // Return

            // Check if card has been changed
            // OK Beep + Set credits on vending machine
            Serial.print("S");
            char error = rfid_transmit(current_credits);
            if(error != 0){
              // Could not update machine credits - attempt to save credits to card again!
              card.credits = current_credits;
              updateAndVerify(addr,card);
            }
          } else {
            // ERR Beep + display "ERR  EEPROM BAD" ?
            //Serial.println("ERR  EEPROM BAD");
            Serial.print("B");
            // Halt PICC
            mfrc522.PICC_HaltA();
            // Return
