RFID Based Attendance System

In this RFID based Attendance System project, we will explain you how can we count attendance automatically by using RFID cards. RFID Technology (Radio Frequency Identification and Detection) is commonly used in schools, colleges, office and stations for various purposes to automatically keep a track of people.  Here we will count the attendance of an authorized person by using RFID.

 

We can divide the complete attendance system into different sections: reader section, control section, driver section and display section. Role of each section is shown in the below block diagram:

Reader Section

This section contains a RFID, which is an electronics device which has two parts - one is RFID Reader and other is RFID tag or Card. When we put RFID tag near to the RFID reader, it reads tag data serially. RFID tag has 12 digit character code in a coil. This RFID is working at baud rate of 9600 bps. RFID uses electromagnet to transfer data from reader to tag or tag to reader.

 

Control Section:

8051 microcontroller is used for controlling the complete process of this project. Here by using 8051 we are receiving RFID data and sending status or messages to LCD.

 

Display section:

A 16x2 LCD is used in this project for displaying messages on it.

 

Driver section:

This section has a motor driver L293D for opening gate and a buzzer with a BC547 NPN transistor for indications.

 

Working

When a person put their RFID tag to RFID reader then RFID reads tag’s data and send it to 8051 microcontroller and then microcontroller compares this data with defined data or information. If data is matched with defined data then microcontroller increment the attendance by one of the tag’s person and if matched is not occurred then microcontroller shows invalid card on LCD and buzzer is beeping continuously for some time.

Circuit diagram for RFID bassed attendance system project is shown above. In the circuit, LCD is connected in four bit mode with 8051 microcontroller. LCD’s RS, RW and EN pins are directly connected at PORT 1 pin number P1.0, P1.1 and P1.2. D4, D5, D6 and D7 pins of LCD are directly connected at pin P1.4, P1.5, P1.6 and P1.7 of port 1. Motor driver is connected at PORT pin number P2.4 and P2.5. and buzzer is connected at P2.6 at PORT2.  [Also check: LCD Interfacing with 8051 Microcontroller]

 

Program Explanation

To program for RFID based attedance system, we first need to include header files and defines input and output pin and variables.

#include<reg51.h>
#include<string.h>
#include<stdio.h>

sbit rs=P1^0;
sbit rw=P1^1;
sbit en=P1^2;
sbit m1=P2^4;
sbit m2=P2^5;
sbit buzzer=P2^6;
char i,rx_data[50];
char rfid[13],ch=0;

After this we need to create a function for delay.

 void delay(int itime)
{
    int i,j;
    for(i=0;i<itime;i++)
    for(j=0;j<1275;j++);
}

Then we make some function for LCD and initialize lcd fuction,

void lcd_init(void)
{
    lcdcmd(0x02);
    lcdcmd(0x28);
    lcdcmd(0x0e);
    lcdcmd(0x01);
}

Here we have some function that we have used in our program. In this we have configured 9600bps baud rate at 11.0592MHz Crystal Frequency. We are monitoring the SBUF register for receiving data.

void uart_init()
{
 TMOD=0x20;
 SCON=0x50;
 TH1=0xfd;
 TR1=1;
}

char rxdata()
{
  while(!RI);
    ch=SBUF;    
    RI=0;
    return ch;
}

After this in main program, we have initialized lcd and UART and then we reads the output of RFID when any one tag on it. We stores this string in an array and then match with predefined array data.

        lcdcmd(1);
        lcdstring("Place Your Card:");
        lcdcmd(0xc0);
        i=0;
        for(i=0;i<12;i++)
        rfid[i]=rxdata();
        rfid[i]='\0';
        lcdcmd(1);

If match occurrs then controller increases the attendance by one. Else beep buzzer runs continuously and LCD shows invalid card.

        if(strncmp(rfid,"160066A5EC39",12)==0)
        {
            count1++;
            lcdcmd(1);
            lcdstring(" Attendance ");
            lcdcmd(0xc0);
            lcdstring(" Registered");
            delay(200);
            lcdcmd(1);
            lcdstring(" Student1 ");
            lcdcmd(0xc0);
            lcdstring("Attnd. No.: ");
            sprintf(result, "%d", count1);
            lcdstring(result);

 

PCB Layout

Here is the PCB layout for RFID based Attendance System: