CN206193856U - Food safety traceability system based on RFID technique - Google Patents

Abstract

The utility model relates to a food safety traceability system based on RFID technique for to data calculate with the MCU unit handled, a display for being directed at arithmetic data advances line display, a prompt tone unit for producing voice prompt information, and a processo, an antenna for producing magnetic flux is connected between providing the energy to passive label and establishhing label and read write line, a ID card that is used for carrying out the password check -up with the read write line, carries out read and write operations to the card. the shelf life of the date of production instant article of the place of production, the food of food is tracked according to food serial number. Can the person of improving production, operator and consumer's organizational structure, solve because technique restriction and the untimely condition of information transfer that causes. Compared with the prior art,

Description

A kind of food security traceability system based on RFID technique

Technical field

The utility model belongs to technical field of food safety, more particularly to a kind of food security based on RFID technique is traced to the source System.

Background technology

In recent years, food security causes the close attention of numerous people.Especially in the frequency of multiclass food safety affair After numerous generation, people come to realise the importance of food security.Meanwhile, food security also result in the Party Central Committee with State Council Pay much attention to, the healthy and life security of the people is considered as the most important thing all the time.Due to the development of current food catenary system Become increasingly complex, the program from food production to packaging is extremely more, therefore, the unsafe factor of food is consequently increased.These mistakes Journey result in food security frequently to be occurred in consumer at one's side, to make that consumer is food-safe to lose the confidence, and is had a strong impact on The stabilization of society and the health of consumer.

Food security is divided into quantity safety, three sides of sustainable safety and quality safety by food security researcher Face.Most important of which is that quality safety.Safety of Food Quality is primarily referred to as high in food nutrition quality, disclosure satisfy that edible people Group ensures the health of eater to the demand of nutrition.For these reasons, when food enters market, entrained by it Food labelling serves vital effect.Meanwhile, relevant departments are also made that strict rule to the normalization of food labelling It is fixed.

Foodstuff traceability control system, that is, food-safe tracking and traceability system, have been referred to as food control at present Department or the food-safe control of consumer and the effective way monitored.But, still neither one internal authority up to now Property definition the trackability of food described.

Due to RFID technique now at present and be widely used in producing, transport, the aspect such as medical, false proof, but in food And apply upper development and its slow, mainly including the following aspects：

1. high cost

Label based on RFID technique is different from conventional bar code or nowadays emerging Quick Response Code, contains inside it Small integrated circuit.Accordingly, with respect to bar code or Quick Response Code, its cost of manufacture is high.If RFID technique is applied at a low price On the commodity of lattice, the cost of the producer, sellers and consumer can all be raised.Price factor determines electronics mark in very broad aspect Label can't be widely used on the various consumer goods at present.

2. data inputting is complicated

In food service industry, it has specific diversity, supplementary material source complexity, short periodicity level transport diversity etc. Feature.If continuous typing merchandise news, will certainly increase the workload of workman during each.List is from the side, just right The development of RFID technique is formed and hindered.And in Data Input Process, the accuracy of Data Enter is obtained with the preciseness of workman Less than effectively ensureing, this also makes the development of the technology lose meaning.

The content of the invention

The utility model is carried to solve RFID technique high cost present in known technology, the complicated problem of data inputting For a kind of simple structure, the food security traceability system based on RFID technique that is easy to install, improving operating efficiency.

The utility model is adopted the technical scheme that to solve technical problem present in known technology：

The food security traceability system for being based on RFID technique includes：

MCU units for data to be carried out with computing and treatment；

It is connected with MCU units, for the display shown to operational data；

It is connected with MCU units, the prompt tone unit for producing information of voice prompt；

It is bi-directionally connected with MCU units, for driving reading and writing device antenna to be communicated with answering machine, realizes read-write, decoding and write Radio frequency identification unit；

It is bi-directionally connected with radio frequency identification unit, for producing magnetic flux to provide energy to passive label and set up label The antenna being connected between read write line；

It is connected with radio frequency identification unit, for carrying out cryptographic check with read write line, operation is written and read to card ID cards.

Further, described radio frequency identification unit is by card reader antenna, electronic tag, the part group of RFID controller three Into electronic tag is connected by card reader antenna with RFID controller.

Further, buzzer is installed inside described prompt tone unit.

The utility model follows the trail of the shelf-life of the place of production of food, the date of manufacture instant food of food according to food numbering.Can To improve the producer, operator and the institutional framework of consumer, the information transmission that solution is caused due to technology restriction is not in time Situation.It is also possible to strengthen the safe system of food China's based on legal system and the restriction of ethics, it is ensured that information it is accurate Property.

Brief description of the drawings

Fig. 1 is the structural representation of the food security traceability system based on RFID technique that the utility model embodiment is provided Figure；

Fig. 2 is the single-chip microcomputer minimum circuit system diagram that the utility model embodiment is provided；

Fig. 3 is that the MCU units that the utility model embodiment is provided are connected circuit diagram with display；

Fig. 4 is the circuit diagram of the antenna that the utility model embodiment is provided；

In figure：1st, MCU units；2nd, display；3rd, radio frequency identification unit；4th, prompt tone unit；5th, ID cards；6th, day Line.

Specific embodiment

For the content of the invention of the present utility model, feature and effect can be further appreciated that, following examples are hereby enumerated, and coordinate Accompanying drawing describes in detail as follows.

Structure of the present utility model is explained in detail with reference to Fig. 1 to Fig. 4.

The STC89C52 chips that the main control chip that MCU units 1 are used is produced for STC Corporation, the chip be a kind of low-power consumption, The 8-digit microcontrollers of high performance CMOS 8, are commonly called as single-chip microcomputer.Meanwhile, the chip has what 8k can be programmed in systems Flash storage.STC89C52 single-chip microcomputers have the function that traditional 51 single-chip microcomputer does not possess, but are also compatible with traditional 51 single-chip microcomputer Institute is functional.Because it has 8 bit CPUs, it is possible to neatly programmed on a single chip.STC89C52 single-chip microcomputers are most Small circuit system is as shown in Figure 2.The structure of the minimum circuit system is mainly included：Reset circuit, oscillating circuit and memory Selection circuit.

STC89C52 single-chip microcomputers have the characteristics that：The single-chip microcomputer possesses 40 number of pins altogether：Wherein power supply, reset is electric Road, power supply, ground connection and EA respectively account for 1 pin；Crystal oscillating circuit accounts for 2 pins；32 I/O interfaces；2 hanging pins.STC89C52 Single-chip microcomputer is 8k bytes Flash piece internal program memories, 256bytesde random storage data storages (Random Access Memory, RAM), possess 32 outer bilateral input/output ports (I/O), 5 interrupt priority levels, 2 16 can compile Journey timer conter, 2 full duplex serial communication ports, house dog (WDT) circuit, on-chip clock oscillator.

1. single-chip microcomputer power supply circuit：The general power supply powered to STC89C52 single-chip microcomputers is 5V, and VCC and GND is confession in Fig. 2 Electric network identifier.

2. crystal oscillating circuit：Using 24MHz crystal oscillator as STC89C52 single-chip microcomputers clock source.

3. reset circuit：It is the important component that single-chip microcomputer normally runs, reset circuit should be ensured that single-chip microcomputer Just once effectively resetted in the moment being powered, RST pins low level need to be connect in single-chip microcomputer normal work.

Pin function according to STC89C52 single-chip microcomputers can be divided into four aspects and be introduced：

1. power pins

VCC(40):Connect 5V power positive ends；

GND(20):Connect 5V power positive ends.

2. external crystal oscillator pin

XTAL1(19)：In the inside of single-chip microcomputer, inputs of the XTAL1 equivalent to a sign-changing amplifier.When with external clock When being attached, for different single-chip microcomputers, the access way of the pin is different, such as when being connected with HMOS single-chip microcomputers, then Need ground connection；When being connected with CHMOS single-chip microcomputers, it is the incoming end of external signal.

XTAL2(18)：The output end of the inverting amplifier of internal oscillator is connect inside single-chip microcomputer.The pin and XTAL1 (19) operate similar.It is input when being connected with HMOS；When being connected with CHMOS, only need to vacantly operate.

3. control signal or with other power supply multiplexing pins

A total of 4 kinds of forms of pin of the type, respectively：RST, ALE, PSEN and EA.

1)RST(9)：That is reset button.It act as reset end and power down protection end on single-chip microcomputer.If single-chip microcomputer earthquake During work, the pin can help monolithic processor resetting to original state；When VCC breaks down, the pin can connect standby Power supply and ensure that single-chip microcomputer is not powered off, such that it is able to continue preserve RAM in data.

2)ALE(30):When external memory storage is accessed, ALE (permission address latch signal) with per machine cycle twice Signal output, P0 mouthfuls low is appeared in for latching.

3)PSEN(29):The pin is the Strobe output of the outer RAM of piece, and just effective when low level is accessed.In piece During outer RAM is read out signal from outside, the end has twice effectively in each cycle, can be read by data/address bus mouthful and referred to Make signal.If accessing piece external signal, then the end no signal occurs.

4)EA(31):The end is to access external RAM control end and only effective when low level is accessed.When the end is electricity high Flush fashionable, single-chip microcomputer access internal RAM 4KB；If exceeding this scope, the end accesses the program of external RAM automatically.If should It is constant that end is always maintained at low level, then access external program memory.

4. input/output (I/O) pin P0, P1, P2 and P3

1)P0(39-22):When chip does not connect external circuit or is not extended, P0.0-P0.7 can be defined two-way 8 Input/output interface.It is when check problem, then defeated from P0 input instruction bytes when piece is contained within EPROM mcu programmings Go out command byte.

2)P1(1-8):P1.0-P1.7 is referred to as P1 mouthfuls, can be used as accurate two-way I/O interfaces.Carried out for EPROM When programming or program check run, the P1 mouthfuls of least-significant byte address that will receive input signal.

3)P2(21-28):P2.0-P2.7 is referred to as P2 mouthfuls, may generally serve as accurate two-way I/O interfaces.Probably it is connected to outside Program storage or when being extended, P2 mouthfuls is used for most-significant byte address bus and sends out most-significant byte address.Program or carry out for EPROM During program ver-ify, P2 mouthfuls of 8 bit address for receiving input.

4)P3(10-17):P3.0-P3.7 is referred to as P3 mouthfuls of 8 interfaces and is difunctional mouth, serves not only as general Accurate two-way I/O interfaces, it is also possible to be used for the 2nd function by every 1, and it is the 1st work(that P3 mouthfuls of every pin can be independently defined The input and output of energy or the 2nd function.P3 mouthfuls of the 2nd function such as table 1.

The menu that P3 mouthfuls of table 1

To sum up：The effect of the pin of STC89C52 single-chip microcomputers can be summarized as：

1) function of the MCU is more, and number of pins is few, thus pin has the 2nd function mostly；

2) single-chip microcomputer is externally in 3 bus forms, and P2 and P0 mouthfuls of 16 bit address buses of composition；By P0 mouthfuls of time-sharing multiplex conduct Data/address bus.

The display 2 used in the utility model is LCD12864 LCD MODULEs, and the liquid crystal display display module has 20 pins, including 8 bidirectional data lines and 6 control lines and power line.

2 points of LCD12864 liquid crystal displays are two screens of left and right, 128 row pixels, 64 row pixels, and whole screen is 128*64 pixel.It is exactly to writing data in DDRAM to the programming of liquid crystal display 2.Before row write data are entered, it is necessary to RAM is first removed, and left and right screen need to be removed respectively.The pin function table of LCD12864 is table 2

The LCD12864 pin function tables of table 2

LCD12864 liquid crystal displays 2 use the screen with character library, and the 128*64 screens with Chinese character can show 4 32 Chinese characters of 16*16 dot matrix of the row of row 8, each display random access memory can show that 1 Chinese character or 2 16*8 dot matrix are complete The display of ASCII character character high.Inside with Chinese word library possesses the character display random access memory buffering area that can provide 128*2 bytes. The display of character is realized by encoding write-in random access memory.According to the difference of write-in content, can show on liquid crystal display Show Chinese character, ASCII character and custom content.

The communication mode of LCD12864 LCDs has two kinds：Respectively serial communication and parallel communications.Due to parallel Communication transmitting data speed is fast, the parallel communications that LCD12864 LCDs is used with the communication mode of MCU.

Display 2 has a chip selection signal for entirety " E ", only when the signal is high level, the just meeting of all of circuit Lose function.Other left and right half screen respectively has selection signal a CS1 and CS2, and respectively low level when, left half screen is chosen respectively With right half screen.In order to distinguish the content of read-write for data are still instructed, a data/commands control line D/I is provided with addition.Root It is as shown in Figure 3 interface circuit to be have devised according to these principles.

Due to having register in read write line chip, therefore, MCU units 1 can be by the reading to register in read write line Write to control read write line chip, and transmit a signal to prompt tone unit 4.Come from the single-chip microcomputer of MCU units 1 when read write line is received After the signal for sending, it will according to non-contact radio frequency cards protocol format, fixation is sent by with antenna 6 and other match circuits The modulated signal of frequency is found.When the presence of ID cards 5 in the range of this is searched out, the LC resonance circuit (resonance in ID cards 5 The frequency of circuit is consistent with the frequency that read write line sends) resonance can be produced under the excitation of electromagnetic wave.

When there is ID cards 5 in the efficient working range of read write line, MCU units 1 send searching signal to card, and card will Return information, sets up the first contact of ID cards 5 and read write line, if there is multiple ID cards 5 in the frequency range that MCU units 1 send When, read write line will start its Anti-knocking mechanism, to ensure the legitimacy of operation.When this occurs, read write line can root Wherein one card is selected according to card number, the card chosen can be verified with read write line, and not selected remain in the spare time Configuration state, the order for waiting MCU units next time 1 to send.After ID cards 5 and read write line carry out cryptographic check success, just can be right Card such as is written and read at the application operating.

The information transmission mode of RFID is Wireless Data Transmission.Its major advantage can be to carry out at data Reason, while safety verification can also be carried out.When being connected with read write line, RFID label tag can enable bi-directional verification machine with read write line System.Before data processing is carried out, label need to carry out three certifications with read write line, and all processes can be encrypted protection.

The key of radio frequency identification unit 3 is radio frequency chip, and the chip selected in the utility model is MFRC522. MFRC522 is that one kind can apply the high integration read-write card family chip in 13.5MHz contactless communications.It is public by NXP A kind of low-voltage, the miniature contactless read-write chip of low cost of exploitation are taken charge of, is the optimal choosing for portable handheld device Select.

MFRC522 is based on advanced modulation and demodulation concept, and it is all types of passive under 13.5MHz to be integrated with Contactless communication mode and communication protocol.The chip internal transmitting portion can drive reading and writing device antenna to be communicated with answering machine, Without the assistance of miscellaneous equipment.Receiver part can improve effectively demodulation and decoding circuit, for processing receiving terminal Signal.Numerical portion processes ISO14443A frames and carries out odd even detection.The chip can support the contactless logical of more high speed Letter, its bidirectional data transfers rate is also very high.One kind that MFRC522 is read and write in family chip as 13.5MHz high integration, its Communication between main frame can carry out SPI, I2C or serial using the less serial communication of line according to different user's requests A kind of selection in pattern, advantageously reduces wiring quantity, the volume of pcb board is reduced, while can also cost squeeze.

MFRC522 can be connected from the interface of different controller chips, and he possesses automatic detection logic, therefore can start Adaptable System pattern is connected with other interfaces.Although it is worth noting that, MFRC522 supports different digital interfaces, and its Interface shape has variation, so, chip is required for examining the annexation of external pin again after resetting every time Survey.

Antenna 6 mainly for generation of magnetic flux, the effect of antenna 6 be provide energy to passive label and set up label with Connection between read write line.13.56MHz radio-frequency antennas and match circuit have three parts：Coil, LC resonance circuits and EMC filter circuit.In the design of antenna 6, it is ensured that it produces the primary condition that a strong electromagnetic field is designing antenna 6. The purpose is to allow card to be power itself by antenna 6.Simultaneously, it is necessary to have enough passbands transmit signal also be antenna One validation criteria of 6 output energy.

The resonant frequency equation of antenna 6 is formula (3.1)：

Wherein, f is resonant frequency, and L is the equivalent inductance of antenna 6, and C is equivalent capacity.In this paper, the work of antenna 6 is frequently Rate is 13.5MHz, if the equivalent inductance L of antenna 6 is too high, C should just diminish.The inductance computing formula of loop aerial 6 is：

In formula (3.2), I1 be the loop aerial length of 6 one weeks, D1 for wire diameter, K for antenna 6 shape because Element.N1 is the number of turns of coil, and P is the coefficient related to loop construction.The computing formula of the quality factor Q of antenna 6 is as follows：

Q can be used to evaluate the delivery efficiency in loop, and its value is bigger, then ability delivery efficiency is higher.If Q values Height, then can make passband narrow, and how too small the energy good fortune at subcarrier frequency is, and then can influence the transmission of modulated signal.

Fig. 4 is the match circuit of antenna 6 and filtering.The signal sent in transmitting portion, pin TX1 and TX2 has envelope What the 13.5MHz carrier energies of signal modulation, the EMC filter circuit constituted with C0 by L0 and C1, C2 and Rq were constituted matches electricity Road drives antenna 6.In receiving portion, R2 and C4 ensures the DC input voitage of RX pins, and R1 and C3 adjusts the friendship of RX pins Stream input voltage.

Product IDs card 5 is individually placed to induction zone, after ID cards 5 are put, LCD liquid crystal displays will distinguish the name of display of commodity Claim, number, dispatching from the factory and the information such as shelf-life.The product information in outgoing label can be correctly shown, expected design mesh is reached Mark.

The properties of product table of table 3

It can be seen that the operating voltage of system is 3.3V, operating current is 5.0V, and system power dissipation is relatively low, for synthesis, is System have good reliability, be hardly damaged, using with it is easy to maintenance, meanwhile, its cost is smaller, with compared with high performance-price ratio.

The above is only, to preferred embodiment of the present utility model, not to make any formal to the utility model Limitation, it is every according to technical spirit of the present utility model to any simple modification made for any of the above embodiments, equivalent variations with Modification, belongs in the range of technical solutions of the utility model.

Claims (3)

1. a kind of food security traceability system based on RFID technique, it is characterised in that food security of RFID technique should be based on Traceability system includes：

MCU units for data to be carried out with computing and treatment；

It is connected with MCU units, for the display shown to operational data；

It is connected with MCU units, the prompt tone unit for producing information of voice prompt；

It is bi-directionally connected with MCU units, for driving reading and writing device antenna to be communicated with answering machine, realizes the nothing of read-write, decoding and write-in Line rfid uint；

It is bi-directionally connected with radio frequency identification unit, for producing magnetic flux to provide energy to passive label and setting up label and read Write the antenna connected between device；

It is connected with radio frequency identification unit, for carrying out cryptographic check with read write line, the ID of operation is written and read to card Card.

2. the food security traceability system of RFID technique is based on as claimed in claim 1, it is characterised in that described wirelessly penetrates Frequency recognition unit is made up of card reader antenna, electronic tag, the part of RFID controller three, electronic tag by card reader antenna with RFID controller is connected.

3. the food security traceability system of RFID technique is based on as claimed in claim 1, it is characterised in that described prompt tone Buzzer is installed inside unit.