Development And Implementation Of A Field Monitoring System Based On AVR Microcontroller

With the development of computer and microelectronics technology, embedded system which composed of variety of single chips or microcontrollers has been widely applied in the fields of industry automation, office automation, building automation and so on. Network has become an important trend for the development of new generation embedded system to achieve the function of long-distance data-collection, romote control, ect.. Ethernet technology combinated with rapid developing embedded technology at present composes Embedded Ethernet technology.The remote monitoring system based on Embedded Ethernet technology completes monitoring and controling tasks through network, extends the monitoring range into a large scale and promotes the control technology to be more networked, more distributed and more opened.The key point of the Embedded Ethernet technology is an embedded network server that offers a protocal transformation tools for traditional nonstandard equipments and offers software and hardware support for users to manage them. A theory is proposed that the low price MCU can be used as a server, which gives a feasible scheme on the connection of monitored equipments and Ethernet. Besides some 32-bit processor in the embedded system at present, there are a large number of 8-bit processors. The 8-bit processors are less cost and used extensively in all kinds of intelligent devices. If we could implement the Embedded Ethernet technology over them, it will bring great economic interest.This paper works on the remote monitoring system based on Embedded Ethernet and constructs an Embedded Web Server monitoring system which is based on AVR single chip. Firstly, several schemes of Embedded Ethernet implementation in domestic and abroad are analyzed to come out a holistic scheme for Web Server remote monitoring system. Then Construct an Embedded Web Server hardware platform based on ATmegal28 as a server and RTL8019 as a network controller, a software platform based on Nut/OS real-time operating system and Nut/Net, acheive the function of Web Server remote monitoring system with the Socket mechanism on the basis of HTTP protocol and CGI technology. Programming the web page of remote monitoring system with HTML, the user can monitor the states of the field equipment via web page. Secondly, wireless sensor network technology are syncretized to bring forward a wireless data collecting scheme based on embedded Web Server, which means adding wireless transceiver units base on nRF905 on embedded Web Server.ATmega128 collects data by a wireless method and transmit data to Network, thus users could monitor equipment state in wireless sensor network.