The Research And Realization Of The RFID Low-frequency Read/Write Device

Radio Frequency Identification (RFED) system is mainly composed of electronic tags and read/write device, it can identify the target automatically and acquire its data through RF signal. The target can be identified by RFID system without physical contact, RFID systems can work in all kinds of adverse environment, can realize multi-objective identification and moving target identification. With great power in objects tracking, identifying, supervision and management, RFID is widely used in various fields of production and daily life, and has become an importantt technology being researched and developed both at home and abroad.According to existing problems that the number of pets is large and hard to be monitored in pet management in the city, this paper presents RFID pet management solution and gives the structure of the system. Because most of the low-frequency readers in market is read-only and can not write into the tag, they can not meet the needs of pet management system. Based on the characteristics of electronic tags we design a 134.2 kHz low-frequency read/write device used in the pet management system.Firstly, the research status and direction of the development of radio frequency identification technology at home and abroad are summarized, and then the background of research projects and sources of topics are introduced. Introduce the structure of radio frequency identification system, workflow, the way of coupling and energy supply and working principles of data transmission and modulation, analyze the structure and function of the read/write device, give the overall plan of the system and put forward hardware and software design principles.Secondly, according to the design principles select the elements of power module, RF module and control module, bring forward the detailed design of hardware circuit of the low-frequency read/write device, and expatiate on the power supply's anti-jamming method and the calculation method of the antenna coil matching value. Introduce the PCB board layout, the principle of the layout of components, debug the hardware circuit after welding and present the module debugging method.Thirdly, introduce the software structure on the basis of hardware circuit of the read/write device, and mainly solve the problem of reading and writing on the tags. According to the characteristic and protocol timing of the electronic tag HITAG S256 this paper give the design idea of ASK coding, capture, AC decoding, Manchester decoding and Biphase decoding, and put forward specific solutions. Debug the system when hardware and software are completed, and give debugging methods and results.