国内外土壤湿度传感器通信协议对比研究  

Comparative study on communication protocols of soil moisture sensors made in China and abroad

作　　者：刘勇[1] 杨娟[1] 王运圣[1] 徐识溥[1] 郑秀国[1] LIU Yong;YANG Juan;WANG Yunsheng;XU Shipu;ZHENG Xiuguo(Institute of Agricultural Science and Technology Information,Shanghai Academy of Agricultural Sciences,Shanghai Engineering and Technology Research Center for Digital Agriculture,Shanghai 201403,China)

机构地区：[1]上海市农业科学院农业科技信息研究所,上海数字农业工程与技术研究中心,上海201403

出　　处：《上海农业学报》2022年第3期121-127,共7页Acta Agriculturae Shanghai

基　　金：上海市科技兴农创新项目[沪农科创字(2019)第2-3号]。

摘　　要：针对农业物联网感知层对传感器接入的需求,选取农业生产中国内外常见的12种土壤湿度传感器,以传感器直接接入物联网为目的,对其通信接口和通信协议进行对比研究。所选取的12种土壤湿度传感器按接口类型可分为RS485接口、SDI-12接口和模拟接口三大类,分别对这3类接口进行了信号采集和通信协议研究,并以STM32微控制器为平台按照各自的通信协议编程实现了对这3类接口传感器的数据采集和转化,获取到了相应的土壤湿度数据。结果表明:Modbus接口协议的传感器是国内主流,协议复杂度最为简单;SDI-12接口协议的传感器国外使用较多,协议复杂度次之;模拟接口作为一种国内外厂商都保留的接口类型,其获取的数据需经过复杂换算才能得到湿度值,且测量数据的准确性取决于厂商提供的校准公式,或需自行校准,协议复杂度最高。Aiming at the demand of sensor access in the sensing layer of Agricultural Internet of Things,12 kinds of soil moisture sensors made in China and abroad and commonly used in agricultural production were selected.For the purpose of sensor direct access to the Internet of Things,their communication interfaces and communication protocols were compared.The selected 12 kinds of soil moisture sensors could be divided into RS485 interface,SDI-12 interface and analog interface according to the interface type.The signal acquisition and communication protocol of these 3 kinds of interfaces were studied respectively.The data acquisition and transformation of these 3 kinds of interface sensors were realized on the platform of STM32 microcontroller according to their communication protocols,and the corresponding soil moisture data were obtained.The results showed that the sensor of Modbus interface protocol was the mainstream in China,and the complexity of the protocol was the most simple.The sensors of SDI-12 interface protocol were widely used abroad,and the protocol complexity was the second.Analog interface was an interface type reserved by manufacturers at home and abroad.The humidity value could be obtained only after complex conversion,and the accuracy of the measured data depended on the calibration formula provided by the manufacturer or self-calibration.The protocol complexity of analog interface was the highest.

关 键 词：土壤湿度传感器 通信协议 RS485 SDI-12 模拟接口 物联网 

分 类 号：S126[农业科学—农业基础科学]