Design And Implementation Of Greenhouse Wireless Sensor Networks

In recent years, the technology of wireless sensor network has been a hot research field in the world. As the increasing requirements of wireless communication and data transfering in industrial automation field, ZigBee technology emerges as the times require. Due to its low cost, low power consumption and high safety, Zigbee quickly becomes the mainstream technology of wireless communication. It is widely used in industry, home automation, agricultural automation and so on.Based on the research of wireless sensor network and ZigBee technology, this dissertation presents a system for the measurement of the temperature, humidity and illumination of the greenhouse. A specific wireless sensor node module was desighed and developed for this system. STM32F103series micro-processors form STMicroelectronics and wireless chips from Zhejiang Rui Ying Company are used in this system to build a wireless sensor network based on ZigBee technology.First, this dissertation is an overall design according to the demand of field work in greenhouse condition. The sensor nodes are designed for the real-time sensation of the temperature, humidity and the quality of the illumination in the greenhouse. The gateway nodes are designed for the management of the data uploaded by the sensor nodes, and they transfer the data collected to the higher server via GPRS.Second, the needs-analysis about the function of sensor nodes and gateway nodes, the selection of suitable hardware module and the hardware design are all involved.Third, according to the hardware design of sensor nodes and gateway nodes, the design of the software module and the hardware module function is realized.Fourth, because the amount of the data transferred between nodes is huge, and the working status of the gateway node needs to be considered, so a user-defined communication protocol must be established. All the sensor nodes and gateway nodes communicate with each other following the user-defined transmission protocol, and the stability of the data transmission is also tested.Fifth, power consumption of this system is deeply studied from both two aspects-hardware and software in order to reduce it. The battery life of the nodes was estimated and the actual power consumption is also tested. Finally, the ground work of this dissertation is summarized, the deficiencies of the work and study are analyzed, and the prospection of the further development of this dissertation is given.