The Research Of Distributed Architecture For Wireless Sensor Networks Nodes

Wireless sensor network (WSN) is composed by a large number of nodes by self-organization, the node is integrated by sensor module, processor module, wireless communication module and power supply module. As the characteristics of the node application environment specificity and the inconvenient of replacing the battery, the energy issue becomes one of the influence and constraint of the spread and development of wireless sensor network bottleneck problems. In addition, WSN nodes are used to collect the information and parameters of the measured environment, as the different application requirements, the node carry different sensor modules, so to make the nodes have versatility and scalability is important issue of today's WSN development.This project aims at improve the traditional structure of node, the distributed architecture program is proposed, so that each module has its own microprocessor, the module can be independently responsible for their own functions, and communicate with the main microprocessor to coordinate work.Through the way of collecting solar energy, research and design the energy collection system with two energy storage: super capacitor energy and iron phosphate lithium battery. The system under the control of MCU MSP430F2122,to achieve the orderly flow of energy from the solar cell to super capacitors, then through DC-DC converter to the iron phosphate battery, and finally to the node load. Apply interference observation to achieve the maximum solar output power control, and use trickle charge mode to maximize the life of lithium battery. Furthermore, energy collection system also has over-current protection and I~2C communication, the node main MCU through the I~2C communication can be configured to the working parameters and get the remaining energy state of system. The solar collection system avoids the one-way attenuation, improves the performance and life of nodes, that conductive to the promotion and application of WSN. In order to achieve nodes versatility and scalability, with the different requirements, can directly replace or add sensor modules at the existing nodes, without having to design new node. Topics introduce the STIM plug and play construction method in the IEEE 1451.2 standard. The sensor modules plug and play in I~2C interface of the main MCU is come true. The node defines the unity and integrity external interface, can be applied in different environments, choose different components to freely configure the system.