The Software Design Of Wireless Sensor Network Node Based On GAINZ Hardware Platform

With rapid improvement of sensor, embedded system,network, wireless communications and distributed computing technology,wireless sensor network has become one of the hottest spots in recent years. By virtue of the functions of information sensoring,data processing,data transmission and receiving,wireless sensor network has a glorious future in its potential of various applications. The hardware and software design of sensor node is one of the most important part of WSN technology research. With ATmegal28L and CC2420,GAINZ provides a low-cost sensor node hardware platform. The IEEE802.15.4 standards,which define the specification of PHY(Physical) layer and MAC(Media Access Control) layer,provide a solution reference for software development of sensor node.Since wireless sensor network can be used in various application environment,dififerent sensor node software designs are practicable. Therefore,network layer and upper OSI(Open System Interconnection) layer protocols should be used based on specific application. Although some research institutions have made capability comprisons of different network layer and upper OSI layer protocols by theoretic analysis and network simulation,the results could not be as believable as that are estimated from real network.Meanwile,sensor nodes are needed for the implementation of wireless sensor network. The PHY layer and MAC layer software of the sensor node must be carefully designed,which needs knowledge and experience of hardware drive development. For resolving this problem,the paper completes the sensor node software design based on IEEE802.15.4 standards by function modularization and procedure oriented.Sensoring, wireless transmission and receiving, CSMA/CA(Sense Multiple Access with Collision Avoidance) and frame format are four elementary function modules of the sensor node software system. The designs and specific implement steps of these modules are presented in the paper. Based on this design scheme,sensor nodes can send their own sensor-data packets to sink node.Thus,a star topology WSN is obtained.Then,for checking the status of the sink node,a RS232 line is used for the serial connection from PC(Personal Computer) to GAINZ. A specific software running in Windows operating system is developed for monitoring the real-time received packet of sink node. A output text file which stores the data information and frame ID(Identifier) is generated by the software at the same time. A task assign software is also developed for controlling the working status of WSN.In conclusion, a new software design method has been brought forword in the paper.The software design containing functions of PHY layer and MAC layer based on GAINZ hardware platform is accomplished. A PC monitoring tool and a task assign tool have been developed and added into the implementation scheme. A wireless sensor network environment has been constructed.