Research On Wireless E-Nose Sensor Network Nodes Based On TinyOS

Wireless sensor networks (WSN) consists of a large number of low-cost micro-sensor nodes,which make up of a muliti-hop self-organizing network through wireless communication.Its purpose is to send sampling data in the network coverage region to observers.The paper has summarized the development of wireless sensor networks,E-nose at home and abroad and discussed the related theories and key technologies,sensor nodes and IEEE 802.15.4/ZigBe Protocol standards,and mainly done the intensive study of wireless sensor nodes in the network hardware,software development tools TinyOS,software design aspects,and according to actual needs E-nose wireless sensor nodes are realized based on the gas sensors.The paper carried out modular design in the sensor node's hardware design.It put emphasis on processor module design based on the MSP430F149,ATmega128L processors,wireless communications module design based on CC2420 chip,and detailed the CC2420 pin interface between the processor used.Against Sink node access interface design with twoRS232 and USB interface which uses FT2232C chip to convert uart to USB interface.and compendiumed the design of power module and sensor board module. Utimately using ATmega128L+CC2420 design proposal to PCB, achieved node's hardware design.Before node's software design,the paper in aspect of node's software design firstly researched micro- embedded TinyOS operating system which is an open source code operating system specialed for wireless sensor network.It has explored TinyOS's system components model,communication model, event-driven scheduling mechanisms, as well as the core mechanism and strategies. TinyOS is a thorough understanding of good design procedures based nodes.Next it did detailed analysis of the data structure TinyOS node information,and carried out wireless transceivers, serial communication module and ADC module program design and at last did the tatal analysis of TinyOS's multi-hop communications components,recounted minimum hop routing algorithm,as well as link quality estimate and neighborhood table management,and father selection,cycles,duplicate packet elimination,queue management in achieve specific Multi-hop communication framework process.On this basis, finish the multi-hop communications based on minimum hop routing algorithm.At last,the paper achieved the design of E-nose sensor nodes based on gas sensors,and the test results were analyzed. By the test, the sensor nodes in the hardware modules work stability, and in this sensor node hardware platform software modules operating normally.