The Design Of Embedded Video Monitoring Terminal Based On3G Technology

With the advances in microprocessor technology, computer network technology, the network digital video surveillance system based on embedded Web has gradually get people’s attention. Image acquisition, image compression and Web features to focus on a small device, can be directly connected to the LAN and the Internet. Users do not need to install any hardware equipment can be watching. The3G technology to maturing and the popularization of the Internet let embedded video monitoring system dispense a variety of complex cable, easy to install, extremely flexible and convenient.The system uses the popular embedded microprocessor ARM, and open-source embedded Linux operating system for the development platform, using CMOS camera to capture the images, transmitted to the Web server after compression, through the3G wireless network card dial-up networking can wait for the monitoring requests of the browser, then provide real-time monitoring image for the browser. Customers need only through a common browser will visit the monitoring terminal, can achieve static image viewing, video viewing and video zoom control by the relevant operation to the web page. This thesis is mainly composed of hardware design, design of the software development platform, the realization of function. This thesis firstly analyses hardware modules:the smallest system to monitor terminal system, the camera interface circuit, USB interface circuit. Followed by the design and build of the software development platform, including embedded Linux operating system transplantation, cross-compilation environment set up, the embedded Web server transplantation, the transplantation of the camera and3G network card driver software and PPP dial-up software transplantation. The third part is the specific implementation of the functional modules of the entire terminal system; complete a series of functions including using V412API to achieve image, format conversion, picture transmission through socket programming, web design and compile, and video play back. In addition, to solve the shortcoming of3G dynamic private IP address cannot be accessed by a computer in external network, this paper proposed to build a virtual local area namely VPN, and part of the implementation. We put the monitoring terminal equipment, VPN server with DDNS service, customer PC together to constitute a virtual local area network. The server distribute VPN IP address for terminal equipment and customer, customers can access and control the monitor terminal after getting its IP by querying DDNS.