Research And Development Of Smart Card Systems Based On Can Bus

Contactless Smart Card and CAN bus both are new products with the rapid development of science and technology. Smart Card technology has been more broadly applied to various areas, specially such as public tranportation, wireless communication, identification, finance and public security etc. CAN bus has some outstanding merits on the aspects, such as reliability, real-time characteristic and agility. In this paper, two kinds of new technologies are combined successfully in order to built the Smart Card System based on CAN bus.Firstly, the state of the art types, applications and development trend of smart cards and bus technology are presented. Then, the overall design of the all-purpose smart card system, the system requirement analysis and system function modules division are introduced. The system actualization process and related key techniques are stated.Secondly, the paper analyses and designs the three parts: data acquisition, data processing and data transmitting. The communication of Smart Card was developed, based on the analysis of ISO/IEC15693 protocol, including hardware design and software flow; then, the data will been transferred for data processing part, completing the processing functions including storage, demonstration, keyboard control and so on; then, through the connection card of converting 232 into CAN, data was transmitted to monitoring PC through CAN bus. Monitoring software and DLL's program needed by embedded system was developed on PC. The design of all kinds of connections and communication protocols combined the three parts into a complete system. The parts have used the modular design. They can not only operate independently, but also been used as a whole. Working in the different movement pattern, the system is easy to promote and the expansion. Redundant measure is designed by hardware and software and minimizes the system disturbance.In data acquisition system, ISO/IEC 15693 protocol was introduced in details, including physical characteristics, radio frequency, signal interface, Initialization, anticollision and transmission protocols with emphasis on anticollision principle and sequence. Discussion on hardware of data acquisition system, hardware schematic diagram and software flow. Monitoring software on PC was programmed by VB6.0, realizing connection with PC and completing demonstration and control function; DLL was programmed by Windows API, enable data acquisition system embeddedinto other systems.In data processing system, the data acquisition was processed. The hardware involves main control module, storage module, displaying modules, keyboard inputting module and simply introduces the design of hardware circuit and selection of the hardware circuit chip. The hardware schematics are put forward .The software aspect is emphasis on the plan of the chip initialization program and the realization of the function of the outer operation, which makes the disposal function transfer to the local equipment as a modularization. Consequently, the local equipment can implement a majority of functions by itself, such as data collection, data management and essential setting prepared for data transmission.In data transmitting system, we designed connection card of converting 232 into CAN, through which realizing monitor between PC and CAN bus. At the same time, hardware circuit realizing this converting function is introduced in detail.In addition, communication modules about CAN bus, such? as initialization module, interrupt module, transmit and receive module, are also programmed.The experiment shows that the Smart Card system based on CAN intelligent nodes can operate stably, reliably and real-timely.