Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe

How to interface RFID with 8051 microcontroller (AT89C51)- (Part 34/45)

By Himanshu Choudhary October 3, 2010

An RFID (Radio-frequency identification and detection) reader is a device which is used to communicate with RFID tags by receiving and transmitting signals. These signals use radio waves for wireless communication.RFID tag is applied to products, individuals or animals to identify and track them. The identification is done through a unique serial number. This topic covers the interfacing of a passive RFID system with AT89C51. The code of RFID tag is also displayed on an LCD interface. The free source code for the program is avaiable in C.

 

 


 

An RFID (Radio-frequency identification and detection) reader is a device which is used to communicate with RFID tags by receiving and transmitting signals. Interface RFID with 8051These signals use radio waves for wireless communication. RFID tag is applied to products, individuals or animals to identify and track them. The identification is done through a unique serial number. This topic covers the interfacing of a passive RFID system with AT89C51. The code of RFID tag is also displayed on an LCD interface. The free source code for the program is available in C. An RFID module basically consists of two parts, namely, a tag and a reader. A typical RFID system consists of an antenna, a transceiver and a transponder (RF tag). The radio frequency is read by the transceiver and the information is transferred to a device for further processing. The information (the unique serial number) to be transmitted is stored in the RF tag or transponder. The transponder contains a chip and an antenna mounted on a substrate. The chip transmits the relevant information through antenna. 

 

An RFID module basically consists of two parts, namely, a tag and a reader. A typical RFID system consists of an antenna, a transceiver and a transponder (RF tag). The radio frequency is read by the transceiver and the information is transferred to a device for further processing. The information (the unique serial number) to be transmitted is stored in the RF tag or transponder.

The transponder contains a chip and an antenna mounted on a substrate. The chip transmits the relevant information through antenna. The antenna also receives the electromagnetic waves sent by the RFID reader.

Different RFID tags work on different frequencies. Here low frequency, 125 kHz, RFID tags have been used. These tags work within a range of 10 cm. When an RFID tag comes in this range, the reader detects it and sends a unique code of the tag serially. This serial code, consisting of 12 bytes, is received by the microcontroller.

 

 

A serial level converter is required for AT89C51 to receive these serial signals. IC MAX232 has been used for this purpose to interface the RFID reader with microcontroller. The circuit connections are as follows:

 

 

Receiver1 (R1) of MAX232 has been used for the serial communication. The receiver pin of RFID reader is connected to R1IN (pin13) of MAX232. R1OUT (pin 12) of MAX232 is connected to RxD (P3.0) of microcontroller.
 
RFID Reader
MAX232
AT89C51
Rx
R1 IN
R1 OUT
Rx

Pins 1-3 of port P1 (P1.0, P1.1 & P1.2 respectively) of AT89C51 are connected to the control pins 4-6 LCD. The unique identification code of RFID tag is displayed on the LCD.

In the program, Timer1 is configured for serial communication. The baud rate is set to 9600bps for data transmission. The LCD is initialized to display the code. When a card/tag comes in the proximity of RFID reader, the microcontroller reads the code and sends it to the LCD module.

 

Project Source Code

###

//Program to interface RFID with 8051 microcontroller (AT89C51) #include<reg51.h>
unsigned int data_out,command=0x80,temp;
sfr lcd_data_pin=0xA0; //P2 port
sbit rs=P1^0;        //Register select 
sbit rw=P1^1;        //Read/Write 
sbit en=P1^2;        //Enable pin
unsigned char card_id[12];

void delay(unsigned int count)    //Function to provide delay
{
    int i,j;
     for(i=0;i<count;i++)
     for(j=0;j<1275;j++);
}

void lcd_command(unsigned char comm)   //Lcd command funtion
{
     lcd_data_pin=comm;
     en=1;
     rs=0;
     rw=0;
     delay(1);
     en=0;
}

void lcd_data(unsigned char disp)  //Lcd data function
{
     lcd_data_pin=disp;
     en=1;
     rs=1;
     rw=0;
     delay(1);
     en=0;
}

lcd_string(unsigned char *disp)     //Function to send string 
{
     int x;
     for(x=0;disp[x]!=0;x++)
    {
         lcd_data(disp[x]);
    }
}
void lcd_ini()                  //Function to initialize the LCD
{
    lcd_command(0x38);          
    delay(5);
    lcd_command(0x0F);        
    delay(5);
    lcd_command(0x80);
    delay(5);
} 

void recieve()     //Function to recieve data serialy from RS232 
{
    unsigned char k;
     for(k=0;k<12;k++)
     { 
         while(RI==0); 
          card_id[k]=SBUF;
          RI=0;
    }
}

void main()
{
    int l;
    TMOD=0x20;            //Enable Timer 1
    TH1=0XFD;
    SCON=0x50;
    TR1=1;                // Triggering Timer 1
    lcd_ini();
    lcd_command(0x81);        //Place cursor to second position of first line 
    lcd_string("UNIQUE CARD ID:");
    delay(200);
    while(1)
    {
         recieve();
         lcd_command(0xC1);        //Place cursor to second position of second line
         for(l=0;l<12;l++)
         { 
              lcd_data(card_id[l]);
          }
      }
}

###

 


Circuit Diagrams

How-to-interface-RFID-with-8051-microcontroller-AT89C51

Project Components

  • AT89C51 Microcontroller
  • LCD
  • MAX232

Project Video


Filed Under: 8051 Microcontroller
Tagged With: 8051, lcd, microcontroller, rfid
 

Next Article

← Previous Article
Next Article →

Questions related to this article?
👉Ask and discuss on EDAboard.com and Electro-Tech-Online.com forums.



Tell Us What You Think!! Cancel reply

You must be logged in to post a comment.

EE TECH TOOLBOX

“ee
Tech Toolbox: 5G Technology
This Tech Toolbox covers the basics of 5G technology plus a story about how engineers designed and built a prototype DSL router mostly from old cellphone parts. Download this first 5G/wired/wireless communications Tech Toolbox to learn more!

EE Learning Center

EE Learning Center
“engineers
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.

HAVE A QUESTION?

Have a technical question about an article or other engineering questions? Check out our engineering forums EDABoard.com and Electro-Tech-Online.com where you can get those questions asked and answered by your peers!


RSS EDABOARD.com Discussions

  • Thermal modelling of repetitive power pulse
  • Redundant XORs
  • No Output Voltage from Voltage Doubler Circuit in Ansys Nexxim (Harmonic Balance Simulation)
  • Discrete IrDA receiver circuit
  • ISL8117 buck converter blowing up

RSS Electro-Tech-Online.com Discussions

  • Help with finding unique wire lug(s)
  • Simple LED Analog Clock Idea
  • Kawai KDP 80 Electronic Piano Dead
  • Saga 1400sv vinyl cutter motherboard issue
  • using a RTC in SF basic

Featured – LoRa/LoRaWan Series

  • What is the LoRaWAN network and how does it work?
  • Understanding LoRa architecture: nodes, gateways, and servers
  • Revolutionizing RF: LoRa applications and advantages
  • How to build a LoRa gateway using Raspberry Pi
  • How LoRa enables long-range communication
  • How communication works between two LoRa end-node devices

Recent Articles

  • What is the LoRaWAN network and how does it work?
  • Understanding LoRa architecture: nodes, gateways, and servers
  • Revolutionizing RF: LoRa applications and advantages
  • How to build a LoRa gateway using Raspberry Pi
  • How LoRa enables long-range communication

EE ENGINEERING TRAINING DAYS

engineering

Submit a Guest Post

submit a guest post
Engineers Garage
  • Analog IC TIps
  • Connector Tips
  • Battery Power Tips
  • DesignFast
  • EDABoard Forums
  • EE World Online
  • Electro-Tech-Online Forums
  • EV Engineering
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • 5G Technology World
  • Subscribe to our newsletter
  • About Us
  • Contact Us
  • Advertise

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy

Search Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe