茶园信息采集无线传感器网络节点设计

针对茶园中所存在的无线通信障碍问题，该文设计了一款适合茶园信息采集的无线传感器网络节点。节点以ATmega128为核心，nRF905射频芯片及其外围电路作为无线通信模块，SHT11空气温湿度传感器和TDR-3土壤含水量传感器及其外围电路作为传感器模块，并以该节点为硬件平台编写了通信协议、应用程序和后台管理软件。分析、测试了节点的功耗和通信距离，在空旷地带，节点的有效通信距离达到150 m，与Micaz节点对比室内外通信距离分别提高了200%和150%。在广东省英德茶园基地进行了组网试验测试，结果表明：网络平均丢包率为0.84%，传感器感知精度达到98.2%，能够满足茶园信息采集的应用要求。

Design of wireless sensor network node for data transmission in tea plantations

A wireless sensor network (WSN) node was developed for information collection in a tea plantation, aimed at boosting wireless penetrating power through communication barriers. The node uses the ATmega128 as the core, a nRF905 RF chip and its periphery circuits as the wireless communication module, SHT11 temperature and humidity sensors and TDR-3 soil moisture sensor as its sensor module. Communication protocol, application program and background management software were compiled and embedded into the node. Communication distance and energy consumption of the node were tested and analyzed. The effective communication distance was measured up to 150m in broad smooth areas. By comparison with Micaz node of Crossbow, the indoor and outdoor distances of the node increase by 200% and 150% respectively. A WSN of 7 nodes was established for measuring temperature, humidity and soil water content in a tea plantation. Experimental results show that the average packet loss rate is 0.84% and the measurement precision is not less than 98.2%. The node is suitable for and could meet the needs of data acquisition in a tea plantation.