The Design And Implementation Of Wireless Multimedia Sensor Nodes

With the feature of multimedia sentience, wireless multimedia sensor networks can be used in the military, civil and commercial fields with promising prospects. As one of the hot research areas in wireless multimedia sensor networks, wireless multimedia sensor nodes have attracted great attention in research institutions at home and abroad. Combining with embedded technology, this thesis introduces a solution of wireless multimedia sensor nodes based on 802.11b protocol and H.264 video encoding.The thesis mainly focuses on the design of hardware platform for wireless multimedia sensor nodes, the kernel customization of Linux operating system, the driver development for the system and the application program development. The thesis firstly discusses the status of WMSN research in world-wide area, and introduces the structure of the wireless multimedia sensor node. The hardware of the wireless multimedia sensor node consists of Hi3512 multimedia processor, and other peripheral apparatuses such as data acquisition module, common interface module and wireless communication module. Secondly, the thesis elaborates the approaches and flow of developing device driver based on Linux. Finally, the thesis details the software design approaches of audio processing module, video processing module, system control module and network communication module.Through the system schematic design, PCB design, hardware and software debugging stage, this thesis has developed a wireless multimedia sensor node, which has audio, video, temperature acquisition function, capable of 25fps VGA format H.264 encoding in realtime and has 2.7Mpbs wireless data transmission rate and so on. According to the test, the node can operate stably, be able to achieve multimedia data acquisition, compression coding and wireless transmission capabilities to meet the design requirements.