The Network Access Control System Design Based On STM32

With the rapid development of smart technology and the widespread promotion of computer applications, smart cards can be seen everywhere in our lives. Radio frequency identification cards are gradually replacing the traditional contactless IC card, becoming the new trend in the field of smart cards. Access control and attendance management system using RF card reader technology, mainly used in enterprises, schools, intelligent community, factory security, attendance and other work. Now, it has become the main trends in the field of a safe working environment, personnel attendance management. The access control system combines Ethernet technology greatly enhance the system’s real-time and versatility. Ethernet is now one of the most widely used LAN, the Ethernet based on TCP/IP protocol has features of long distance transmission, generic interface and convenient communication, not only widely used in the commercial sphere, but also into industrial equipment in the field.The design of four web-based access control system, can simultaneously control four single door, every door has a real-time attendance function, users can use the host computer to register a new user, modify the controller IP address and do other operations. STM32F103RET6is used as the main chip, the STM32family chips is low power consumption, cost-effective, mature and stable product, the hardware design of the control panel, use the principle of practical stability and saving cost. In embedded software, to realize the network control function, the STM32processor transplants TCP/IP protocol stack LWIP and combines the Microchip newly developed network controller chip ENC424J600, Access Controller as the server of TCP communication. RF card converted into binary data through the card reader usually via Wiegand interface connecting to controller,Wiegand signal can transmit distance and process convenient, a processor is convenient to deal with multiple Wiegand signal and thus to control multiple doors, this paper designed four Wiegand signal acquisition and processing. The design of the host computer using Visual C++and Python language to write, simple to operate, PYTHON program runs in the background to get user real-time credit card data, the VC host used to register new users and so on.