Research And Implementation Of Wireless Sensor Network In Agricultural Greenhouse

With development of microelectronics and computer technology,manufacturing a large quantity of miniature and low-cost sensor and building wireless sensor network has become a mature technology and applied in industry,agriculture,medical treatment and military fields.The miniature and low cost of sensor means that sensor only has limited data storage,operation and communication ability.Moreover,it only takes along limited electricity and needs regular charging.It is also basic conditions to be considered when applying wireless sensor network.Wireless sensor network is applied to environment monitoring of agricultural greenhouse to study the routing protocol among sensors so that it can make full use of remaining electricity of sensor effectively and prolong the life cycle of network.Hierarchical routing protocol is applied to the wireless sensor network of agricultural greenhouse,which is determined by analyzing and comparing various routing protocols in the wireless sensor network.To solve node energy consumption disequilibrium problem caused by hierarchical routing protocol LEACH in selecting cluster head at random,the remaining energy of each node is proposed to be deemed as the indicator of selecting cluster head.The higher the remaining energy of the node is,the greater the probability of becoming cluster head is,and node with high enough remaining energy becomes cluster head in turn.When the node that is selected as the cluster head sends message to other periphery nodes,other nodes select the cluster they want to join according to the intensity of the received message and notify the corresponding cluster head nodes,then the cluster head node distributes TDMA timetable for member nodes in the cluster.At the stable data transmission stage,the nodes in the cluster sends data to cluster head nodes after redundancy processing.At the end of each round,the cluster head is selected and clusters are divided again according to the above method to realize dynamic load balancing of nodes in the network and prolong the life cycle of network.NS2 simulation experiment indicates that new protocol saves energy and prolongs network service life,compared with LEATH protocol.At last,wireless sensor network nodes are designed using CC2430,which realizes real-time monitoring of temperature,humidity and illumination intensity in the greenhouse.