Research Of Embedded Remote Monitoring And Control System Based On HTTP Protocol

The way of monitoring and controlling local area or global area with network is the primary trend of information and control system. Embedded system has many advantages, such as small size, strong function, high reliability and flexibility etc. It has been penetrated into industry, agriculture, national defense, education, scientific research, consumption and so on, it's playing an important role in promoting the various fields to upgrade technology and product, accelerate the automation process and improve production efficiency.As a representative of network control, embedded remote monitoring technology combining with traditional industry has resolved the problem of heterogeneous network interconnection in industrial measurement and control field. It retains the advantages of embedded devices, and extends the control of field devices to any corner of the earth through internet, so that we can truly realize the device's remote management and control.The main research purpose of this thesis is researching and designing a solution on remote monitoring and control system using embedded microprocessor and network technology, it is also making foundation for integrating between network control and information network in future. In order to take fully use of the advantages of embedded device and network control, based on profoundly study of TCP/IP protocol and embedded Linux operation system, this thesis design and implement an embedded remote monitoring and control system based on HTTP protocol, using B/S(Browser/Server) architecture, which feature is designing embedded web server sub-system using microprocessor--STM32F103RB owing Cortex-M3 core and embedded browse sub-system using microprocessor—S3C2410A owing ARM9 core, they could build a LAN or WAN, via such network, the server could response for the access request of browser, after validating the validity of user's info, it will generate and post a web page which contains the current status and parameters'data of the device controlled by server to network, and user will receive this web page and control the status of the remote devices by the control button on web page, besides, the data on web page will keep updating.To implement the previous purpose, the main contributions in this dissertation are as follows:1,According to the development station and foreground of current remote monitoring and control system, analyzing the features of embedded remote monitoring and control system, and summarizing four ways to enable embedded system to support TCP/IP protocol.2,To implement parsing HTTP protocol based on STM32F103RB, firstly, analyzing data packet structure, connection management, flow control and reliability of TCP protocol. Learning HTML based on WWW theory and designing web page program of monitoring and control system. Besides, analyzing work mode, features and message format of HTTP protocol.3,According to the different design demands on embedded web server and browser to chooses suitable processor chip and different suitable ways for supporting TCP/IP protocol stack. Embedded browser adopts Linux OS with TCP/IP protocol stack and embedded server adopts W5100 which realize TCP/IP protocol stack with fully hardware.4,Building embedded browser system platform using the 5-lyer structure on embedded system development based on Linux. Analyzing the startup process and realization theory of Bootloader--vivi, and learn the common commands of vivi. Analyzing the core structure and device management of Linux OS, and transplanting Linux-2.6 core and root file system into S3C2410A,based on these building an embedded GUI, and transplanting Konqueror/E successful which provide a fine visual interface for remote monitoring and control.5,Basing on STM32F103RB design the hardware circuit of embedded web server, and implement W5100's driver according to it's network state transition of TCP server mode. Implementing web server program based on the hardware, which mainly includes HTTP protocol parsing program, web page data updating program, Base64 decode program and web page program.6,Designing network communication demo software to validate the network transmission speed of the server system, by testing, it has proved that the server completely satisfy the demand of monitoring and control system which has little data and real-time transmission. Testing the whole remote system by building one network and it's result satisfy expected purpose, this also settles the foundation for the future complicated application. Besides, providing one actual application blue print.