Design And Implementation Of Embedded Web Server Monitoring System Based On Cortex-M3

With the substantial increase of the chip integration, embedded chip technology is widely used in the agricultural, industrial, commercial, military and other fields. With the popularity of the Internet network technology, the various embedded products access to the network, shared network resources,be remote measured and controlled by client, make the information transfer from specific embedded products to the other terminal of the network become more and more important. The embedded WEB technology came into being. It is a technology that connect the embedded technology with the Internet technology. Client can use the browser to surveil the embedded device. Construct the embedded WEB platform is one of the key research direction in the surveillance field.There are many problems in the process of achieve the embedded WEB server. One of the problem is that in the industrial control equipment network, people often use the bus of CAN, RS232, RS485for communication. The distance of this method is very short.This method can not adapt the update of itself and also did not connect with the Internet.The other problem is that some embedded devices which connected to the Internet are use the ARM11,ARM9and DSP chip that increase in the cost of equipment. And the operating system on them are often customized with large program which use large memory to running. The system is unstable and difficult to expand its function. Based on the above, the paper use the processor of ARM Cortex-M3as an embedded processor, achieve the embedded devices connecting with the Internet.Considering the development of the embedded Web server as well as the characteristics of the Cortex-M3processor which are low cost, low power consumption, fast processing speed, superior performance, simple structure, short develop cycle and are widely used in the wireless device and embedded platform. Based on above, the paper construct the embedded WEB network hardware platform based on the Cortex-M3of the STM32series of ARM microcontroller. Running the LWIP protocol stack and the application layer program on it. It also resolve the network communication problems on the non-operating system condition.First of all, for the data collection module of the system.The paper analyzes the output data form of the camera and uses the STM32to configure the camera to output the data of YUV type.Secondly, for the automatic focus module of the system.The STM32uses the DMA function to receive and store the data. Then STM32uses the focus evaluation function to judge the definition of the image which are stored just now and control the motor to change the position of lens that make the image clearly through the pole algorithm.Finally, for the data output module of the system.The STM32configure the camera to output the RGB type data and store them in the data block of the HTTP protocol, waiting for the transmission. When the terminal connect signal received, the STM32uses the HTTP protocol to sent the data to the terminal monitor, achieve the monitoring function.We test the server based on the STM32F107VCT6microcontroller on the ARM development board. The results proved that client can use the browser to access embedded WEB equipment through a proprietary IP address, real-time monitor the designated area. So the embedded WEB server metioned in this paper can achieve the require of low-cost and low-power. It can use the LWIP protocol stack and the HTTP protocol to make the embedded devices connect to the Internet through the case of non-operating system, achieve the monitoring function on the browser. It can be used in the monitoring field about classroom and office which have good theoretical value as well as the wind market applications.