Design Of Handheld UHF RFID Reading And Writing Device Based On Linux

RFID(Radio Frequency Identification) is a technology using radio signals to identify and obtain electronic tags’ data with no any physical contact. Today, both in the production, logistics, and in access control, security, RFID has deep into people’s life and social fields. For now, the research and development of low frequency(LF) and high frequency(HF) RFID technology have been matured, their application market has also been becoming saturation. However, the development of ultra-high frequency(UHF) and microwave RFID technology is in full swing, and the market’s demand for these two frequency RFID technologies is also growing. After visiting and analyzing of the market, with the in-depth study of UHF RFID, this article determined to design a UHF RFID reader.Firstly, this article introduces the development process of RFID technology and the current development situation at home and abroad, then analyzes the prospect of the RFID industry combined with China’s strategy of the Internet of things. After this,this article introduces the research’s background, significance and objectives.Secondly, this paper introduces the operational principle of UHF RFID system and analyzes its hardware structure. Meanwhile,determining the working parameters of the RFID reader and the hardware/software platform which can meet the design requirements, and further planning the development process of the reader.According to the development process of the reader, this paper firstly analyzes the hardware schematic diagrams which connect the main control chip and radio frequency chip and completes the programming of UART, SPI, NANDFLASH, GPIO, AS3992 bare-metal driver. Then, this article analyses the ISO18000-6C protocol, which UHF RFID technology relies upon, and lists the common radio frequency transceiver commands specified in the agreement, and success in software realization.In order to further improve the reader’s performance, transplanted embedded Linux operating system into AM1808. The article introduces the Linux system architecture, kernel space and user space in detail and analysis steps and the key techniques of transplantation of Linux system deeply combining with the Linux system architecture. Lastly, transplanted Linux system into the main control chip successfully.After the transplantation of Linux system, developed the device driver on the basis of this operating system. Firstly, this article narrations the Linux virtual file system,which as the core technology of Linux device driver development. According to the architecture and requirements of the Linux virtual file system, developed the related hardware device driver and tested part of hardware drivers successfully.Finally, the article summarizes problems which appeared in the development process, illustrates the shortage of my own technology and makes arrangement for the next step work.