Interface RFID With Arduino Uno

Radio-Frequency Identification (RFID) uses electromagnetic fields to transfer data through wireless.

  • RFID Devices consist of two part
    • Tag
    • Reader
  • Tag contain electronically stored information.
  • Information read by the reader.


  • A RFID system uses tag, attached to the objects for identification.
  • Readers send a signal to the tag and read its response.
  • Tag is read-only the tag uses the radio energy transmitted by the reader.
  • Each tag have unique serial number,by using this tag number it is easy to identify product details.

Rfid Reader

  • There are different type of reader available in market.
    • Passive Reader Active Tag.
    • Active Reader Passive Tag.
    • Active Reader Active Tag.

Passive Reader Active Tag

  • System has a passive reader which only receives radio signals from active tags (battery operated, transmit only).

Active Reader Passive Tag

  • System has a active reader, which transmits interrogator signals and also receives authentication replies from passive tags.

Active Reader Active Tag

  • System uses active tags a woken with an interrogator signal from the active reader.


  • Transportation payments.
  • Transportation and logistics.
  • Public transport.
  • Libraries.
  • Hospitals and healthcare.

Hardware Required

  • RFID Reader.
  • RFID Tag.
  • Arduino.

Rfid Pinout

  • Vin= +5V.
  • Tx= Rx of Microcontroller.
  • Gnd= Ground.


virtual Circuit


 char input[12];
 int count = 0;
 void setup()
 void loop()
 count = 0;
 while(Serial.available() && count < 12)
 input[count] =;
 Serial.println("I  received: ");
 for(int i=0;i<12;i++)