Introduction

Radio-frequency identification (RFID) and Barcode detectors are being used in different sectors for various purposes. They are being used in Shopping malls, Software firm, Library, Labs and many other places. As there wasn’t any project using RFID or Barcodes so we thought about doing a project implementing RFID.

What is RFID?

Radio-frequency identification (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, attached to an object, through a reader for the purpose of identifying and tracking the object. Some RFID tags can be read from several meters away and beyond the line of sight of the reader. The application of bulk reading enables an almost-parallel reading of tags.

The tag's information is stored electronically. The RFID tag includes a small RF transmitter and receiver. An RFID reader transmits an encoded radio signal to interrogate the tag. The tag receives the message and responds with its identification information. Many RFID tags do not use a battery. Instead, the tag uses the radio energy transmitted by the reader as its energy source. The RFID system design includes a method of discriminating several tags that might be within the range of the RFID reader.

Our Project

The objective of this project is to implement an automated attendance system for schools with a comparatively new and promising technology known as Radio-Frequency Identification or RFID in short. In this system every student has a RFID tag containing a unique identity code. Before entering the school the student will have to hold the RFID tag near a RFID reader which is directly connected to a PC using serial port. A software program inside the PC will collect the identity codes from the RFID reader and take necessary actions to save the attendance information inside a database. On each working day after a predefined time the software will scan the database to find those students who are not present that day and send SMS to their guardians. The same software will be used to view attendance history by student or by class, generate and print attendance oriented reports and for the overall management of the system.

Required Instrument and Estimated Cost

No.	Instrument	Quantity	Price (BDT)
1.	Radio-frequency identification (RFID)	1	5000
2.	MAX 232	1	-
3.	RFID Tags	Many	15(Per Tag)
4.	Breadboard	1	200
5.	Serial Converter	1	200
6.	IC 7805	1	-
7.	Capacitors(.1/1/10 microF)	Many	-
8.	Wires	Many	-

Initially an amount around 7000/- BDT is required. Our project also requires a PC. Also a serial port (for desktop computer) or a serial converter (for laptop) is required to interface the RFID with the PC. Additional equipments can be used to improve the project such as an antenna to improve the signal or a GPRS device to send sms.

Additional Equipment and Their Cost (optional)

No.	Instrument	Quantity	Price (BDT)
1.	GPRS device	1	5500
2.	RFID Antenna	1	-

Design and Procedure

Our project can be best described in four parts.

1) Circuit Design and interfacing:

Our plan was very simple and easy to implement. The Block diagram is as follows:

The circuit was a simple interfacing of the RFID with MAX232 using the TX pin and then another connection using the TX pin of the MAX232 with the PC. A buzzer was connected to determine whether the RFID responds to the Tags or not. A vcc of 5V was given through the 7805 using a 12V source. The detailed circuit diagram is given below:

2) Identification:

The RFID will generate a number after receiving signal from any RFID tag. The numbers are used for identification and saved to a text document. A simple java program is written for taking reading from RFID tags and saving them in a text document. Also a timer was set so that the readings will be taken for a set amount of time and after that the database will start checks the readings for necessary updates.

The code is given below:

import java.util.Date;

import java.text.DateFormat;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.io.*;

import java.util.*;

import javax.comm.*;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

public class SimpleRead implements Runnable, SerialPortEventListener {

static CommPortIdentifier portId;

static Enumeration portList;

InputStream inputStream;

SerialPort serialPort;

Thread readThread;

static byte[] readBuffer;

public static void main(String[] args) {

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

Calendar cal = Calendar.getInstance();

System.out.println(dateFormat.format(cal.getTime()));

System.out.println(cal.getTime().getHours()+":"+cal.getTime().getMinutes()+" ");

int hour=cal.getTime().getHours();

int minute=cal.getTime().getMinutes();

int second=cal.getTime().getSeconds();

int currentTime=hour*3600*1000+minute*60*1000+second*1000;

int TargetHourStart=12;

int TargetHourEnd=17;

int TargetMinStart=00;

int TargetMinEnd=(TargetMinStart+2)%60;

int TargetTime=TargetHourStart*3600*1000+TargetMinStart*60*1000;

int TargetTimeEnd=TargetHourEnd*3600*1000+TargetMinEnd*60*1000;

int TimeDifference=(TargetTime-currentTime+24*3600*1000)%(24*3600*1000);

if(!(currentTime>=TargetTime&&currentTime<=TargetTimeEnd))

{

try

{

Thread.currentThread().sleep(TimeDifference);

}

catch(Exception e)

{

}

}

cal=Calendar.getInstance();

System.out.println(cal.getTime().getHours()+":"+cal.getTime().getMinutes()+" ");

try

{

}

catch(Exception e)

{

System.out.println("File open Failed");

}

System.out.println("After File");

portList = CommPortIdentifier.getPortIdentifiers();

while(true)

{

while (portList.hasMoreElements()) {

portId = (CommPortIdentifier) portList.nextElement();

if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {

if (portId.getName().equals("COM13")) {

SimpleRead reader = new SimpleRead();

cal = Calendar.getInstance();

hour=cal.getTime().getHours();

minute=cal.getTime().getMinutes();

second=cal.getTime().getSeconds();

currentTime=hour*3600*1000+minute*60*1000+second*1000;

if(currentTime>TargetTimeEnd)

{

Thread.currentThread().destroy();

}

}

else

{

System.out.println("The port is:"+portId.getName());

}

}

}

}

}

public SimpleRead() {

System.out.println("Reader waiting for data...");

try {

serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);

} catch (PortInUseException e) {}

try {

inputStream = serialPort.getInputStream();

} catch (IOException e) {}

try {

serialPort.addEventListener(this);

} catch (TooManyListenersException e) {}

serialPort.notifyOnDataAvailable(true);

try {

serialPort.setSerialPortParams(9600,

SerialPort.DATABITS_8,

SerialPort.STOPBITS_1,

SerialPort.PARITY_NONE);

} catch (UnsupportedCommOperationException e) {}

readThread = new Thread(this);

readThread.start();

}

public void run() {

try {

Thread.sleep(20000);

} catch (InterruptedException e) {}

}

public void serialEvent(SerialPortEvent event) {

switch(event.getEventType()) {

case SerialPortEvent.BI:

case SerialPortEvent.OE:

case SerialPortEvent.FE:

case SerialPortEvent.PE:

case SerialPortEvent.CD:

case SerialPortEvent.CTS:

case SerialPortEvent.DSR:

case SerialPortEvent.RI:

case SerialPortEvent.OUTPUT_BUFFER_EMPTY:

break;

case SerialPortEvent.DATA_AVAILABLE:

readBuffer = new byte[20];

try {

while (inputStream.available() > 0) {

int numBytes = inputStream.read(readBuffer);

}

System.out.println(new String(readBuffer,1,11));

FileWriter outputStream = null;

outputStream = new FileWriter("D:\\rfid.txt",true);

outputStream.write(new String(readBuffer,1,11)+"\r\n");

System.out.println("AFTER WRITE");

outputStream.close();

}

catch (IOException e)

{

System.out.println("File Error");

}

break;

}

}

}

3) Database access and update:

The database contains the necessary information of all the students. A timer was set for the database to start checking after the timer for reading the RFID tags has ended. Then the database will read the RFID tags from the text document and make necessary update to the database. Finally the name and mobile numbers of the parents of the students who are absent will be saved in another text document.

4) Finalizing and sending sms:

We used the API from Grameen Phone in our code for sending sms. The program will read the name and mobile numbers from the text documents and send sms to inform them the students were absent. The code is given below:

/*

* To change this template, choose Tools | Templates

* and open the template in the editor.

*/

package sms2;

/**

*

* @author Nayeem

*/

import java.util.Date;

import java.text.DateFormat;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.io.*;

import java.util.*;

import javax.comm.*;

import com.grameenphone.playground.*;

import com.grameenphone.*;

import com.grameenphone.sendsmsrequest_xml.SendSMSRequest;

import java.net.URL;

import java.security.SecureRandom;

import java.security.cert.CertificateException;

import java.security.cert.X509Certificate;

import javax.net.ssl.HostnameVerifier;

import javax.net.ssl.HttpsURLConnection;

import javax.net.ssl.KeyManager;

import javax.net.ssl.SSLContext;

import javax.net.ssl.SSLSession;

import javax.net.ssl.TrustManager;

import javax.net.ssl.X509TrustManager;

import java.io.*;

import java.sql.*;

import java.util.Calendar;

/**

*

* @author Nayeem

*/

public class SMS2 {

/**

* @param args the command line arguments

*/

public static void override_security() {

try {

X509TrustManager tm = new X509TrustManager() {

@Override

public X509Certificate[] getAcceptedIssuers() {

return null;

}

@Override

public void checkServerTrusted(X509Certificate[] paramArrayOfX509Certificate, String paramString) throws CertificateException {

}

@Override

public void checkClientTrusted(X509Certificate[] paramArrayOfX509Certificate, String paramString) throws CertificateException {

}

};

SSLContext ctx = SSLContext.getInstance("TLS");

ctx.init(null, new TrustManager[]{tm}, null);

SSLContext.setDefault(ctx);

HttpsURLConnection conn = (HttpsURLConnection) new URL("https://serverAddress").openConnection();

conn.setHostnameVerifier(new HostnameVerifier() {

@Override

public boolean verify(String paramString, SSLSession paramSSLSession) {

return true;

}

});

conn.connect();

} catch (Exception ex) {

System.out.println("Exceptional Code!\n\n\n\n\n");

ex.printStackTrace();

}

}

public static void send_sms(String to, String content) {

String registrationID = "vampireegg";//provide your registered user ID

String password = "ohyV7N3Q5"; //provide password which you got after registering from web

String fromMSISDN = "8801731125092"; //provide the mobile number that was registered with your user ID.

String toMSISDN = to;//provide any GP mobile number

String smsPort = "5001";

double charge = 0.00; //

//String chargedParty = "8801718026337"; // chargedParty should be the source mobile number

int msgType = 4; //provide 1-Ring tone, 2-Logo, 3-Uap Push, 4-Text (160 character)

String contentArea = "test";

String msgContent = content; //provide message which want to send

try {

System.out.println("Successful World1!\n\n\n\n\n");

WebServiceGPADPBizTalkSMSOrchestrations service = new WebServiceGPADPBizTalkSMSOrchestrations();

WebServiceGPADPBizTalkSMSOrchestrationsSoap port = service.getWebServiceGPADPBizTalkSMSOrchestrationsSoap();

SendSMSRequest messageRequest = new SendSMSRequest();

System.out.println("Successful World2!\n\n\n\n\n");

messageRequest.setRegistrationID(registrationID);

messageRequest.setPassword(password);

messageRequest.setSourceMsisdn(fromMSISDN);

messageRequest.setDestinationMsisdn(toMSISDN);

messageRequest.setSmsPort(smsPort);

messageRequest.setMsgType(msgType);

messageRequest.setCharge(charge);

System.out.println("Successful World3!\n\n\n\n\n");

messageRequest.setChargedParty("8801731125092");

messageRequest.setContentArea(contentArea);

messageRequest.setMsgContent(msgContent);

System.out.println("Successful World4!\n\n\n\n\n");

sendsmsresponse_xml.schemas.biztalk.adp.gp.SendSMSResponse result = port.sendSMS(messageRequest);

/*sendsmsresponse_xm1.schemas.bizta1k.adp.gp.SendSMSResponse result =

port.sendSMS(messageRequest);*/

System.out.println("Result = " + result.getStatus() + " " + result.getMsgID()); //It shows message sending result…

System.out.println("Successful World!\n\n\n\n\n");

} catch (Exception ex) {

System.out.println("Exceptional World!\n\n\n\n\n");

ex.printStackTrace();

}

}

public static void main(String[] args) {

override_security();

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

Calendar cal = Calendar.getInstance();

System.out.println(dateFormat.format(cal.getTime()));

System.out.println(cal.getTime().getHours()+":"+cal.getTime().getMinutes()+" ");

int hour=cal.getTime().getHours();

int minute=cal.getTime().getMinutes();

int second=cal.getTime().getSeconds();

int currentTime=hour*3600*1000+minute*60*1000+second*1000;

int TargetHourStart=11;

int TargetHourEnd=15;

int TargetMinStart=3;

int TargetMinEnd=52;

int TargetTime=TargetHourStart*3600*1000+TargetMinStart*60*1000;

int TargetTimeEnd=TargetHourEnd*3600*1000+TargetMinEnd*60*1000;

int TimeDifference=(TargetTimeEnd-currentTime+24*3600*1000)%(24*3600*1000);

if(!(currentTime>=TargetTimeEnd))

{

try

{

// Thread.sleep(TimeDifference);

}

catch(Exception e)

{

}

}

cal=Calendar.getInstance();

System.out.println(cal.getTime().getHours()+":"+cal.getTime().getMinutes()+" ");

System.out.println("Hello World!\n\n\n\n\n");

try{

// Open the file that is the first

// command line parameter

FileInputStream fstream = new FileInputStream("D:\\sms.txt");

// Get the object of DataInputStream

DataInputStream in = new DataInputStream(fstream);

BufferedReader br = new BufferedReader(new InputStreamReader(in));

String value;

int i=0;

String name="",cellno="";

while((value = br.readLine()) != null)

{

if(i==0)

{

name=value;

i=1;

}

else if(i==1)

{

cellno=value;

System.out.println("name = "+name+" cell = "+cellno);

send_sms(cellno,name+" is absent today.");

i=0;

Thread.sleep(5000);

}

System.out.println(i+" name = "+name+"cell = "+cellno);

//if(i==0)i=1;

//if(i==1)i=0;

//System.out.println(value);

}

// send_sms("8801718026337", "Hi Nayeem");

}

catch(Exception ex){

System.out.println("Unable to read file");

}

}

}

Problems and Solutions

We encountered many problems as this was our first time using RFID and also there was very little information available about it. We did our best to learn from our mistakes and experimenting again and again.

1) RFID is available in very few places in Bangladesh and it also costs more than twice its usual price where it is available. We bought ours at PYLABs but they could help us very little about how to use it effectively.

2) The range of the RFIDs available is very short. It was said that the range would be 5-10 meters but in practical when we were using it, the range barely seemed to be 2-4 meters at most. This was a big problem for us since we thought the RFID wasn’t working properly.

The range can be improved by adding an antenna to the RFID to receive signal from a afar.

3) The pins of the RFID were very short and it was impossible to place it on any breadboard normally. We tried to use rails but even that couldn’t solve our problems. Finally we had to take a risk and weld wires to the pins to use the RFID. It was a risky procedure as the RFID could be damaged.

4) The RFID wasn’t working properly without a 12-5 volt converter. Giving direct 12 volt to the RFID is suicidal as one of our RFIDs was damaged in this way. So care should be always taken when connecting power to the RFID.

5) When taking inputs from the RFID, various times garbage values were shown instead of proper values. This could be caused by incorrect connection or small diode. Also this could have caused by the noise around as the RFID detects radio frequency from the RFID tags. Care should be taken to avoid this problem.

6) RFID tags aren’t unique. Two tags can have the same value. So it isn’t always possible to detect if someone cheated whether intentionally or unintentionally. Unless a solution for this is found RFID is risky to use in high level or important sector.