The Design And Implementation Of Wireless Transport Station Based On Campus Card Data Acquisition System

With the constant development of information technology, the development of embedded system has become increasingly complex. Some embedded systems have implemented TCP/IP protocol stack, making it possible for some electronic devices connect to the Internet. Some embedded systems have implemented graphic user interface enhancing interactivity with users. As function of embedded system has continually strengthened, its application is widely used in security monitoring, industrial control, access control, attendance and many other areas.A typical application of campus card is in the working staff attendance. In this application, the attendance information is acquired by a campus card reader on the school bus, but the data is transferred to the database manually. In order to facilitate the collection and management of data, we have introduced a campus card data acquisition system based on wireless network. In this system, the data acquisition terminal transmits data to the wireless base station by the wireless network, then the wireless base station transmits data to the back-end database by wired network. This paper discusses the design and implementation of the wireless base station.Based on the features of the embedded system application, and by using key technologies related to embedded system, such as hardware platforms, operating systems, drivers, file system, network etc, this paper designs and implements an embedded wireless base station with serial-Ethernet transform function, making wireless station transfers received data to the database correctly and timely.Firstly, a new system architecture using the wireless theory is designed. According to its workflow, the whole system is divided into four parts, that is card read terminal, wireless base station, the wireless protocol between the terminal and the station, the WPKI architecture base on the whole system. This paper focuses on the wireless base station.Secondly, in the whole, the analysis and design of the wireless base station is made. According to the characteristics of the combination of embedded software and hardware, detailed analysis about wireless base station is made in hardware and software respectively, and the hardware component modules,software workflow and function modules,software development environment are determined.Then, the construction of hardware and the build of software system are implemented. In the part of hardware, Microprocessor and Flash,SDRAM,RS232,Ethernet interface circuits,the wireless module are analyzed. In the part of software, the main task is to build the system and create the development environment. In this part, the vivi start workflow,the function and composition of the embedded Linux operating system,CS8900A-driven principle and the characteristics of file system are deeply studied. The implementations of porting these parts are detailed analyzed.Finally, it is the implementation of the applications. Applications based on the wireless station includes serial,Ethernet and the transform between above two. Applications in the server are the management and operation of the database. In the debugging part, the way in debugging is illustrated by an example.The wireless base station has already been completed, and its practical value is verified in the usage. Some targeted expansions can be carried out in accordance with the actual needs. For other similar embedded development, it is also a good guidance.