The Design And Implementation Of A Communication Interface For Zigbee Sensor And Smart Phone

With the rapid development of mobile Internet, smart phones have swept around the world. Apple, Android, Windows Phone and other smart phones continue to attract the user’s attention. More and more people’s lives cannot leave this kind of communication tools or computing platforms. At the same time, wireless sensor network has received international attention, and is widely used in many areas:health, environment and smart building monitoring. Unfortunately, the communication between smart phones and wireless sensors generally use wireless communication, such Wi-Fi and Bluetooth, or use server to transfer data. However, with the extensive application of wireless sensor networks, how to make sensor node to be a plug-and-play peripheral for smart phone in order to make it easier to access the wireless sensor networks become an increasing urgent needs of users.After research, we find that there are a variety of communication interfaces of smart phone. Among these interfaces, the headphone jack is the only truly open, universal and compatible interfaces.In this paper, we design and implement duplex data communication interface AudioHTG based on smart phone audio jack.In this way, we success to convert sensor nodes to be a plug-and-play peripherals for smart phone. This paper presents two kinds of coding for audio analog signal:8bits valid data coding and dynamic buffer coding. Dynamic buffer is more flexible that8bits valid data coding and achieves a higher throughput and higher bandwidth utilization.In addition, based on the traditional LZW compression algorithm and Huffman coding, we propose LZW-Huffinan compression algorithm,In this paper, we build an experimental platform consist of some sensor motes GenOS-301whose operate system is TinyOS and a smart phone whose operate system is Windows Phone7. Finally, when the smart phone audio baud rate is1378bps and buffer length is512bits, the throughput of dynamic buffer coding is1355bps and bandwidth utilization exceeds98%. Compared with traditional LZW compression algorithm and Huffman coding, the proposed LZW-Huffinan algorithm achieves much higher compression ratio. When the size of dynamic buffer range from512bits to1024bits, compression ratio is from20%to50%.