CN204423400U - A kind of RFID technique read write line for campus verification system - Google Patents

Abstract

The utility model discloses a kind of RFID technique read write line for campus verification system, this read write line of this radio frequency identification is made up of parts such as single-chip microcomputer, external data memory module, Keysheet module, Chinese fonts lcd module, radio-frequency module, real-time clock module, power management module and serial communication modulars, the wireless radio frequency identification reader-writer that the utility model provides applies automatic identification technology, microcomputer software and hardware technology, radio-frequency technique and information security technology, can realize the acquisition function to the various information in campus.This reading and writing device system has portable, the advantage such as volume is little, cheap, intelligent and low-power consumption.

Description

A kind of RFID technique read write line for campus verification system

Technical field

The utility model belongs to radio RF recognition technology, particularly relates to a kind of RFID technique read write line for campus verification system.

Background technology

Radio RF recognition technology RFID (Radio Frequency Identification) is a kind of non-contacting automatic identification technology, can realize automatically identifying and remote real-time monitoring management.Communication distance can be far away from several centimetres to tens meters, and its major advantage is that environmental suitability is strong, and round-the-clockly can contactlessly complete automatic identification, tracing and managing, and can penetrate nonmetal identification, antijamming capability is strong.Therefore, RFID technique is used widely all over the world.And China is at the early-stage in this respect, most of equipment still adopts technology and the achievement of introduction, therefore studies this technology and is applied to comprise the needs that agriculture every field becomes current national economy.

RFID is a kind of non-contacting automatic identification technology, and its ultimate principle utilizes radiofrequency signal and Space Coupling (electromagnetic coupled or electromagnetic propagation) transport property, realizes the automatic identification to being identified object.Because campus (particularly School) security incident takes place frequently in recent years, government, society and school side require to strengthen campus room entry/exit management all in a hurry.But the middle and primary schools of current more than 90%, particularly central and west regions school all also rest in the management lack of standardization of labor management, hand-written registration, especially easily cause the careless omission of campus security management.Just based on this background, have developed this system, with very easily operating, the identity realizing every student accurately, fast identifies, solves the safety problem of school by the mode of relatively low cost.

Utility model content

The defect existed for above-mentioned prior art and deficiency, the purpose of this utility model is, a kind of RFID technique read write line for campus verification system is provided, this reading and writing device system has portable, the advantage such as volume is little, cheap, intelligent and low-power consumption, can realize the acquisition function to the various information in campus.

In order to realize above-mentioned task, the utility model adopts following technical solution:

A kind of RFID technique read write line for campus verification system, it is characterized in that, the read write command of main frame can be sent to electronic tag by this read write line, then mailing to the data encryption of electronic tag from main frame, delivers to main frame after the data deciphering that also electronic tag can be returned; Less radio-frequency is known read write line and is made up of single-chip microcomputer, radio-frequency module, display module, memory module, real-time clock module, Keysheet module, serial communication modular, power management module, low voltage detecting module and watchdog module: described single-chip microcomputer selects C8051F020 type single-chip microcomputer as system master unit, completes the cooperation control to modules; Described radio-frequency module adopts MFRC530 type radio frequency chip, complete the read-write to data in the middle of electronic tag, EMIF height end interface selected by described single-chip microcomputer, and adopt address to communicate with radio frequency chip with the mode of multiplexed data bus, described electronic tag selects MifareS50 electronic tag; Described display module adopts SO12864 type chinese liquid crystal display interaction content, jointly realizes human-computer interaction interface with button; Described memory module selects AMD to walk abreast FLASH AM29LV040B for saved system chip with Chinese characters, and memory module selects storer FLASH AT45DB081B of new generation to preserve some other information of data and the system collected; Described clock module selects PCF8563 type multifunction timepiece/calendar chip system to provide real-time clock; Described key-press module adopts a I/O extended chip PCF8574 to expand the I/O port of single-chip microcomputer, and then uses matrix form interface mode to design keyboard, the input service of completion system operational order; Described serial communication modular uses RS232 serial communication mode to realize the communication of single-chip microcomputer and host computer, this module selects the MAX3221 chip of MAXIM company to realize the conversion of single-chip microcomputer CMOS level and host computer RS232 interface level, and this module selects SN65LBC184 to realize communication at a distance as RS485 transceiver; Described watchdog module: the anti-interference strengthening system, system can be recovered after meeting strong jamming collapse voluntarily.

In this wireless radio frequency identification reader-writer, in described radio-frequency module, the match circuit of MFRC530 read-write chip comprises EMC low-pass filter, receiving circuit, antenna-matching circuit and antenna, described EMC low-pass filter carries out suitable filtering to output signal, restrain high-order harmonic wave, be optimized to the delivery of electrical energy of reading and writing device antenna; The data receiving the transmission of MifareS50 card are responsible for by described receiving circuit, and MifareS50 electronic tag uses half duplex communication mode to realize read write line and sends data to MifareS50 card, and the data that MifareS50 snaps into read write line transmit working load modulation principle.

In this wireless radio frequency identification reader-writer, described power management module is made up of LTC4055, TPS7333 and MAX756 chip, three type of power can be provided for single-chip microcomputer, MFRC530 and other chips, described LTC4055 chip is responsible for system lithium cell charging, described TPS7333 chip provides 3.3V operating voltage for whole system, and system voltage is risen to 5V with the needs of MF RC530 analog operation voltage of satisfying the demand by described MAX756 chip.

The beneficial effects of the utility model are:

The utility model main control module adopts the C8051F020 single-chip microcomputer of high-performance, low-power consumption, and this single-chip microcomputer employs the unexistent technology of some standard 8051 single-chip microcomputers, more more complex than standard 8051 in configuration and programming.Such as: SMBus bus, spi bus, Cross port switching technique, FLASH in-system programming, FLASH safety and hybrid power source system etc.These features are all simplify system, reduce system power dissipation, improve entire system performance and have laid a good foundation.The radio frequency chip MFRC530 being operated in 13.56MHz of another key modules of system employing Phlips company has carried out the reading writing working to electronic tag, and its 3.3V digital operation voltage can reduce system power dissipation.

By modularization programming, the design completing reading and writing device system software comprises external data memory module, Chinese fonts lcd module, UART0 serial communication modular, battery voltage measurement module, SPI spread F LASH module and radio-frequency module MF RC530 etc.

Utilize radiofrequency signal and Space Coupling (electromagnetic coupled or electromagnetic propagation) transport property, realize the automatic identification being identified object, the identity that the utility model finally realizes every student accurately, fast identifies, solves the safety problem of school by the mode of relatively low cost.

Accompanying drawing explanation

Below in conjunction with the drawings and specific embodiments the utility model is further explained explanation.

Fig. 1 is rfid system theory diagram;

Fig. 2 is reading and writing device system basic functional block diagram;

Fig. 3 is MF RC530 hardware circuit diagram;

Fig. 4 is EMC low-pass filter circuit and receiving circuit;

Fig. 5 is the match circuit of antenna;

Fig. 6 is AT45DB081B hardware circuit diagram;

Fig. 7 is FM18L08 hardware circuit diagram;

Fig. 8 is steady pressure of system circuit;

Fig. 9 is LTC4055 charger hardware circuit;

Figure 10 is system main program flow chart;

Figure 11 is the communication process of read write line and card.

Embodiment

Fig. 1 is rfid system theory diagram, and RFID is a kind of non-contacting automatic identification technology, and its ultimate principle utilizes radiofrequency signal and Space Coupling (electromagnetic coupled or electromagnetic propagation) transport property, realizes the automatic identification to being identified object.Rfid system can be different because applying its composition different, but be substantially all made up of electronic tag, read write line and computer data base management system three parts,: the information that read write line will send, the carrier signal being carried in a certain frequency after encoded outwards sends through antenna, after the electronic tag entering reading and writing device antenna scope receives this pulse signal, circuits in card in chip is modulated this signal, decode, is deciphered, and then judges command request, password, authority etc.If read command, control logic circuit then reads for information about from storer, after encryption, coding, modulation, send to read write line again by card internal antenna, read write line is delivered to CIS and is carried out relevant data process after carrying out demodulation, decoding, deciphering to the received signal; If the write order of amendment information, the internal charge pump that relevant controlling logic causes promotes operating voltage, and the content in flash EEPROM is rewritten; If through judging that the password of its correspondence and authority are not inconsistent, then return error message.

Fig. 2 is reading and writing device system basic functional block diagram, system can be divided into single chip control module, radio-frequency module, Chinese fonts lcd module, real-time clock module, key-press module, serial communication modular, watchdog module and power management module etc., CPU (central processing unit) single-chip microcomputer: the core control portions of system, mainly completes the cooperation control to modules.

Fig. 3 is MF RC530 hardware circuit diagram, and MF RC530 is the core component of native system, and its is supported and different microprocessor direct interfaces, and the parallel port signal of support has two kinds: one is independently address and data bus; Another kind is multiplexing address and data bus.Powering on or after hard reset, MF RC530 resets its paralleling microprocessor interface modes detect the interface type of present microprocessor at every turn.C8051F020 has the external data memory interface (EMIF) can accessing chip external memory and chip external memory mapping device.Here, MF RC530 radio-frequency module is equivalent to chip external memory mapping device.EMIF can select to be operated in multiplex mode or multiplex mode, is controlled by the state of the EMD2 position in register EMI0CF.

Fig. 4 is EMC low-pass filter circuit and receiving circuit, and Mifare system is based on 13.56MHz frequency, and this frequency is produced by a quartz crystal oscillator, for driving the fundamental frequency of MF RC530 and the 13.56MHz energy carrier wave as driven antenna.So not only can produce the emissive power of 13.56MHz, and higher harmonic wave can be launched.In order to meet Electro Magnetic Compatibility principle, need a low-pass filter to carry out suitable filtering to output signal, restrain high-order harmonic wave, optimization is to the delivery of electrical energy of reading and writing device antenna.The data that receiving card sends are responsible for by receiving circuit, use internal reference voltage output pin VMID as the input electromotive force of RX pin.In order to reduce disturbance, need with electric capacity by VMID pin ground connection.Receiving unit needs to connect a voltage divider between RX and VMID pin, realizes with two resistance.In addition, need to be connected in series an electric capacity between aerial coil and voltage divider.

Fig. 5 is the match circuit of antenna, and in figure, the value of electric capacity Cs and Cp depends on antenna itself and environment, be 27pF, Cp is 180pF according to inductance selecting tuning initial value Cs; Good decipherment distance can be reached when being 160pF through the value that the value that overtesting obtains Cs is 47pF, Cp.

Fig. 6 is AT45DB081B hardware circuit diagram, the SPI universal serial bus that AT45DB081B uses.The spi bus interface module SPI0 of C8051F020 Embedded can complete the accessing operation of 4 line full-duplex serial bus, this module has 4 external interface pin: MOSI (main output is from input), MISO (primary input is from output), SCK (serial clock) and NSS (from selection), above-mentioned SPI pin assignment carries out line, and the SCK of SCK and AT45DB081B of single-chip microcomputer connects.Serial clock (SCK) signal is the output of main device and the input from device, for synchronous main device with from the serial data transmission of device on MOSI and MISO line.When SPI0 is as main device, produce this signal.In the design, single-chip microcomputer is as main device, produces serial clock (SCK) signal.

Fig. 7 is FM18L08 hardware circuit diagram, and FM18L08 capacity is 32K byte, has 15 address wires.The design adopts high port as the external data memory interface of single-chip microcomputer, data line and address wire multiplex mode equally.Use different chip selection signals to distinguish external data memory MF RC530, AM29LV040B and FM18L08.The CS of FM18L08 can at negative edge latch address, therefore do not adopt latches least-significant byte address, the least-significant byte address wire (A7 ~ A0) of such FM18L08 and the P7 port of data line (D7 ~ D0) and single-chip microcomputer connect, address signal time delay when employing 373 can be avoided to latch, increases the reliability of application.

Fig. 8 is steady pressure of system circuit, and native system selects the adjustable LDO Regulator REG1117 of output voltage to realize DC/DC voltage transitions, for battery and system provide voltage.The DC voltage of 9V ~ 12V that IN voltage input end input AC adapter exports, output terminal OUT exports the voltage being approximately about 5.5V.The output voltage of REG1117 is adjustable, is the voltage of about 5.5V.The output voltage of REG1117 is adjustable, can carry out regulation output voltage by arranging two resistance in figure.10 μ F electric capacity of output terminal parallel connection can suppress high-frequency signal to reflect.

Fig. 9 is LTC4055 charger hardware circuit, and the output voltage (about 5V) of REG1117 provides power supply by the WALL end being input to LTC4055 after two electric resistance partial pressures for it; In addition, the output of REG1117 is connected to load end for system through a forward diode provides power supply.Because LTC4055 has unique ability to monitor the existence of adapter, when external adapter exists, LTC4055 can select adapter as power supply for load provides power supply, is lithium cell charging by BAT pin simultaneously.After external adapter is removed, battery current flows to OUT end by built-in low-loss " ideal " diode, is load supplying, thus pressure drop and power consumption is reached minimize.Two emitting led Power supply states being used to refer to system.

Figure 10 is system main program flow chart, and native system adopts main-slave structure to design, and the every part of program becomes a file by modular design, and debugging is by combined debugging more afterwards separately.Main control unit C8051F020 single-chip microcomputer mainly completes the integration of whole system and the coordination of intermodule.Under the control of system, read the user profile of keyboard, after single-chip microcomputer process, be kept at data-carrier store or deliver to LCD MODULE show gathering the information come; Or data are write in electronic tag.When needs communicate with host computer, the realization of whole communication protocol is responsible for by single-chip microcomputer.

Figure 11 is the communication process of read write line and card, and read write line realizes by controlling radio frequency chip MF RC530 the control of Mifare sheet, and MF RC530 is the communications carrier between read write line and card.

The utility model person of an ordinary skill in the technical field also can understand in addition to the foregoing, can change combination further in this explanation and illustrated specific embodiment.Although the utility model gives diagram explanation with regard to its preferred embodiment, but person skilled in the art is understood that, in spirit and scope of the present utility model limited in the attached claims, also can make all changes and variation to the utility model.

Claims (3)

1. the RFID technique read write line for campus verification system, it is characterized in that, the read write command of main frame can be sent to electronic tag by this read write line, then mailing to the data encryption of electronic tag from main frame, delivers to main frame after the data deciphering that also electronic tag can be returned; Less radio-frequency is known read write line and is made up of single-chip microcomputer, radio-frequency module, display module, memory module, real-time clock module, Keysheet module, serial communication modular, power management module, low voltage detecting module and watchdog module:

Described single-chip microcomputer selects C8051F020 type single-chip microcomputer as system master unit, completes the cooperation control to modules;

Described radio-frequency module adopts MFRC530 type radio frequency chip, complete the read-write to data in the middle of electronic tag, EMIF height end interface selected by described single-chip microcomputer, and adopt address to communicate with radio frequency chip with the mode of multiplexed data bus, described electronic tag selects MifareS50 electronic tag;

Described display module adopts SO12864 type chinese liquid crystal display interaction content, jointly realizes human-computer interaction interface with button;

Described memory module selects AMD to walk abreast FLASH AM29LV040B for saved system chip with Chinese characters, and memory module selects storer FLASH AT45DB081B of new generation to preserve some other information of data and the system collected;

Described clock module selects PCF8563 type multifunction timepiece/calendar chip system to provide real-time clock;

Described key-press module adopts a I/O extended chip PCF8574 to expand the I/O port of single-chip microcomputer, and then uses matrix form interface mode to design keyboard, the input service of completion system operational order;

Described serial communication modular uses RS232 serial communication mode to realize the communication of single-chip microcomputer and host computer, this module selects the MAX3221 chip of MAXIM company to realize the conversion of single-chip microcomputer CMOS level and host computer RS232 interface level, and this module selects SN65LBC184 to realize communication at a distance as RS485 transceiver;

Described watchdog module: the anti-interference strengthening system, system can be recovered after meeting strong jamming collapse voluntarily.

2. RFID technique read write line as claimed in claim 1, it is characterized in that, in described radio-frequency module, the match circuit of MFRC530 read-write chip comprises EMC low-pass filter, receiving circuit, antenna-matching circuit and antenna:

Described EMC low-pass filter carries out suitable filtering to output signal, restrains high-order harmonic wave, is optimized to the delivery of electrical energy of reading and writing device antenna;

The data receiving the transmission of MifareS50 card are responsible for by described receiving circuit, and MifareS50 electronic tag uses half duplex communication mode to realize read write line and sends data to MifareS50 card, and the data that MifareS50 snaps into read write line transmit working load modulation principle.

3. RFID technique read write line as claimed in claim 1, it is characterized in that, described power management module is made up of LTC4055, TPS7333 and MAX756 chip, three type of power can be provided for single-chip microcomputer, MFRC530 and other chips, described LTC4055 chip is responsible for system lithium cell charging, described TPS7333 chip provides 3.3V operating voltage for whole system, and system voltage is risen to 5V with the needs of MF RC530 analog operation voltage of satisfying the demand by described MAX756 chip.