In this tutorial, we will learn how to interface RFID reader RDM6300 or RDM630 with Arduino. Both of these RFID readers communicate via a serial connection on UART and follow the same interfacing with Arduino thus this tutorial will be compatible with both types of RFID readers. First, we will give you a brief description of the RDM6300 module which is cheaper than RDM630 and easily available, its pinout and connection with the Arduino Board. Then we will show you a sketch which will enable us to identify EM4100-compatible tags via this RFID reader.
We have a similar guide with ESP8266 and ESP32:
RDM6300 RFID reader
RFID stands for Radio Frequency Identification. It is a tagging identification system that uses electromagnetic waves in radio frequency to transfer data. An RFID system consists of a passive card or tag and an active read or write device which is RDM6300 in our case.
RDM6300 RFID module is a low-cost RFID reader. You can purchase it for less than 5$ as compared to RDM630 which costs approximately $10-15. Both of the modules work on a 125kHz radio frequency. Therefore, they are able to detect RFID tags or cards which can communicate with RFID readers at 125KHz frequency. RDM6300 RFID module works on transistor logic or in short TTL logic. It means you need to provide 5 volt dc to power supply pins of this module. It has a UART communication function. In other words, it can communicate with microcontroller through a UART serial communication. It has TTL RS232 format.