System Of Gas Environment Monitor Based On 6LoWPAN Technique

With the increasing air pollution problems, the study of gas environmental monitoring system is imminent. The development of networking technology enables the detection of harmful gases more intelligent, realtime data can be monitored completely under unattended,thus saving a lot of labor costs. In wireless sensor networks, network communication technology, sensor technology, embedded technology, gradually entered into our lives and provided convenience for us.Based on studying a lot of knowledge of existing wireless sensor network,this thesis describes a system of gas environment based on wireless sensor network application architecture which is divided into four main parts: the node, protocol stacks, gateways, remote transmission. This thesis focused on the designation and implementation of environmental monitoring system based on 6Lo WPAN.Also,the 6Lo WPAN protocol stack was applied into the specific air pollution monitoring system.It provides a demonstration of the industry.Firstly, this thesis designs four monitoring nodes to achieve the perception of information and intelligent control. Each node is constructed by STM32 microprocessor as the core and the semiconductor chip AT86RF231 radio transceiver the transmitting and receiving data,while connecting a USB-to-serial circuit, E2 PROM power circuit, oscillator and reset circuit.The data is transmitted by low power wireless communication.They constitute IPv6 communication protocol in the wireless sensor network. Peripherals are connected to four gases simultaneously sensor can detect hydrogen sulfide, ammonia, sulfur dioxide, PM2.5 / PM10.0 five kinds of air pollution gases.Secondly, the design realized a 6Lo WPAN star network. Every PAN was transplanted into a Contiki operating system which supports the nextgeneration communication protocolIPv6 running in a personal wireless network.Constructing the 6Lo WPAN protocol stack with the standard of IEEE802.15.4,the packet data transmit in a lowpower 6Lo WPAN network.Thirdly, using the embedded gateway platform.In addition to aggregating the data of 6Lo WPAN network to construct system gateway,it also provided the client interface applying the upload data.Using CORTEX A8 DB development board equipment as the gateway to transplant Labview into the embedded device.This method can save a lot of time to develop software. The data was transmitted via Ethernet to the remote monitoring terminal after aggregating.After interfacing with the gateway,the remote monitoring system draws the waveforms.Combined with the atmospheric quality standards, the abnormal data can cause alarming via SMS and email to response timely.Finally,after realizing the application platform,this thesis tests the dataaware information and the connectivity of gas data and the control of the remote data transmission and shows the result of test.