How to Interface RFID with Arduino?

Last Updated on March 16, 2024

rfid with arduino

RFID or Radio Frequency Identification is one of the best identification method, in this method a RFID module sends RF (Radio Frequency) signal that powers RF “tag” then the tag responds with unique ASCII and HEX serial number. Here every RF “tag” sends back unique number, it can be used as secure key system or tracking system.

Some times Active RF tags transmits HEX code without any external source.

ID – 12 LA

The company ID-Innovations makes this simple and easy to use RFID readers that are easily interfaced into the microcontroller project. The ID innovation series of RFID comes in three versions ID-2, ID-12 and ID-20. All types have the same pin out and works with different RF tags (Most suitable for 125KHz tags) that are commonly used. There is options provided for antenna to extend sensing coverage range, These RFID readers send their data via 9600 baud rate serial manner which is easily read by Arduino and other microcontrollers.

pinout of id12 la


Arduino Hookup

rfid arduino schematics

rfid pcbBy the way it is very easy to connect ID 12-LA RFID reader with Arduino, but note that the pins on these readers are not spaced properly for use with bread board hence you may use sparkfun RFID breakout, the pin D0 is connected with Arduino D0/Rx pin (digital pin 0). This reader provides LED/Buzzer pin (reader pin 10) that will light/buzz when a tag is read.

Arduino Code to Read Tag



/* RFID ID12 */

char val; // variable to store the data from the serial port

void setup() {
Serial.begin(9600); // connect to the serial port

void loop () {
// read the serial port
if(Serial.available() > 0) {
val =;

This simple Arduino code helps to read RF tag number through serial monitor.

After reading the tag code we can use that code to control Arduino pins for specific tag controlled operations.

pdf-icon RFID ID-12LA Data sheet

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