The Write And Read Of Image Biometrics Based On RFID Card

One major characteristic in Network Information Age is individual status digitization and recessiveness. How to identification a person's identity accurately,The protection of information security is a critical social problems in today's information age. Traditional identification methods are usually converted into personal identification number marking the status of things, including keys, documents, ATM card, user name, password, and so on. These traditional status distinction method existence obvious shortcoming:Individual items easily lost or forged, personal password easily forgotten or mistaken.Even more serious is that these systems can not distinguish between the real identity of the owner and a logo of the impersonators, once other people have obtained these identification, may have the same authority.Moreover, the traditional characteristics of a password for the identification technology is also increasingly difficult to meet anti-terrorism, criminal investigation, information, and financial sectors high security requirements.For anti-terrorism, criminal investigation, information security, financial security, and so the need for biometric technology research and application has been an unprecedented world attention.The so-called biometric identification technology is, by computer and with a variety of sensors and biometric principles, and other high-tech means closely integrated, using the inherent human physiological characteristics and behavioral characteristics, in their personal capacity to carry out the identification.Inborn physiological characteristics, and more for congenital; characteristics is the result of habit, most of the acquired.With the rapid development of electronic information technology, smart cards(IC card)are now very popular in our life. Radio Frequency Identification(RFID) card is becoming a new fashion in the application field of smart card,replacing the traditional contacting IC card. So it is of great practical significance to study the technology of RFID Card and develop the read&write device of RFID card for its generalization.The traditional identity of the IC card and biometric technology used in combination, has the widespread application prospect.The intelligent IC card uses its own memory, the computation function,The biometric features stored in the card, may carry on the off-line authentication on the spot, both raised the efficiency, and has saved the networking online inquiry cost,Avoided"recognizing the card did not recognize people"the phenomenon effectively, to prevent the loss due to card and password leak and the damage.The common concept of the RFID card and the basic working principle of RFID system are explained chiefly in the first part of this paper.Then,a read&write module of Mifare1 RFID card is developed ,based on the modular designing mind.The users of application system may develop their practical products rapidly with our module without understanding the details of RFID technology.The read&write module can not only do the control and read&write operations of the RFID card,but also can be redeveloped.The way to implement the read&write module is discussed in detail,icluding two parts,the hardware and the software. The former part includes the constitutes of the system,the design of the interface between MCU and the chip of RFID module,and the realization of the hardware circuits. And the latter mainly introduces how to drive the RFID communication and encapsulate the operation of the card into functions which can be transferred by the customers conveniently. The functions are irralated with hardware by doing its encapsulation according to the rules of software engineering.In order to enhance the read&write module the versatility and the extendibility, the hardware design followed the modular design concept. The entire read&write module is mainly composed of the following several parts:(1) Control MCU;(2) Radio frequency read&write chip;(3) Antenna and matching circuit; (4)Buzzer, LCD display and serial interfaces such as the external circuit.The first part, Control MCU,Mainly to provide the read and write control operation of radio frequency chips ,Such control operations reflected in two aspects:1. The control of RF read&write chip. Through the control of RF read&write chip, user may according to own need to choose or the closure radio frequency read-write function in MCU. When the application system has the low power loss request, does not need when the radio frequency read&write chip has worked, such control mode is essential. Moreover, through the MCU power supply control, may use the software way to realize the radio frequency read&write chip on electricity replacement.2. Through data line, address wire, pilot wire and so on concurrent control connection,MCU connect with RF read&write chip.control RF read&write chip work normally, realize the communication with the RFID cards.Moreover, master control MCU carries on the correspondence through the serial communication connection and the PC side, the convenient user will develop the application procedure writes down in MCU. At the same time, draws out the master control MCU surplus I/O and the interrupt pin, may for the user expansion use.The second part, The RF read&write chip, Responsible for receiving the control of the MCU and complete communication operations with the RFID card operationIn order to work properly, the RF read&write chip must choose the appropriate parallel interface to connect with the MCU. In order to transmit, the receive stable high frequency signal, the RF read&write chip must through the high frequency filter circuit to connect the antenna part.The third part, The antenna , Including the coil and matching circuit, This is an essential part of the RF read&write module .The RF read&write module must depend upon the magnetic flux which the antenna produces is the RFID card provides the power source, in the read-write module and between the RFID card the pass-along message.In order to cause the antenna normal work, the antenna coil must through the passive match circuit connection radio frequency read-write chip antenna pin.