The Research And Design Of Entrance Guard System Based On Near Field Communication Technology (NFC)

Near Field Communication (NFC) is a new technology expanding on the basis of RFID, it can exchange data between devices in the range of several centimetres. NFC technology fully has low price, low power, strong compatibility and other characteristics the short distance wireless interconnection equipment has. The natural safety of NFC makes it become a highly competitive technology in the field of short distance wireless communication, and it is very suitable for entrance guard system. Therefore, this paper study an entrance guard system technology based on (Near Field Communication:NFC).(1) Introduce the related concepts, development and standardization process of NFC technology. It illustrates the basic working principle and mode of NFC, then elaborates on4core specification, analyse the mode of communication, modulation, coding, anti-collision mechanism, frame structure, transmission protocol, etc. of international standard. summarizes the advantages of NFC technology.(2) Designing entrance guard system based on NFC technology and STM32F101control chip as the core, including power module, digital display, buzzer alarm access controller hardware circuit, key input, watchdog, memory,485communication circuit, RTC circuit, NFC card reader interface circuit and door’s lock control circuit, then drawing circuit schematics and PCB board, choosing the materials of equipment components, and welding debug circuit board successfully.(3) Using modularized software design method, using C language to design the access controller software based on ARM Cortex-M3kernel, it includes the watchdog, button, display, communication485, card reader, door’s lock, etc. Finishing the compiler of all programs by Keil uVision platform and successfully carrying out communication485, human-computer interaction, controlling electronic lock, read-writing card, etc.(4) Based on Modbus-RTU protocol, it designs the communication protocol between entrance guard system’s main station and access controller, rules the commands and read-writing register between main station and access controller, then verifies the communication protocol of entrance guard system by serial debugging assitant. It achieves the expected designing requirements.NFC technology is a new idea and way of the access controlling and management. It gives the users more convenience and better interactive way, meanwhile it brings more advanced, intelligent and convenient management scheme to the rulers. This paper studies and designs the entrance guard system based on NFC. During the research, it refers the mature designing experience and ideas at home and abroad and also designs a small entrance guard system based on NFC. It basically achieves the design requirements, but remains to be further improved in terms of the functions of software and communication mode.