| Agriculture is the basic industry of the national economy.Agricultural Internet of Things is one of the important ways to develop modern agriculture.It has a profound and positive impact on the development of our country’s agricultural economy.It uses various sensing devices to measure the environmental parameters of crop growth,the environment parameters are sent to the server using communication technology,and processed through the gateway on the way,in order to monitor the growing environment of crops in real time.However,in the face of the complex situation of different agricultural production terrains,various types,and different scales,the existing gateways cannot flexibly adjust various parameters such as communication mode,data transmission rates,transmission distances,etc.Communication protocols are also different from each other.In order to solve the above problems,this paper selects STM32 with high performance,low power consumption and abundant resources as the development platform to design and implement the agricultural Internet of Things gateway,which can flexibly select communication methods and communication protocols according to actual agricultural production scenarios and functional requirements,and also provide users with a platform that supports multi-communication access,multi-protocol conversion and communication module configuration.This gateway has strong applicability and practical application value.According to the characteristics of the three-layer architecture of the Internet of Things,the gateway design is divided into three layers: the agricultural environment data collected by the perception layer is uploaded to the network layer through Zig Bee,Lo Ra,Bluetooth,and RS485 communication.In the network layer,the user-defined Kframe structure is used as an intermediate bridge to realize the conversion between the four communication protocols: Modbus,Zig Bee,GSXY,and LWXY,and use Wi Fi or GPRS wireless communication to upload the converted data to server.The user selects the communication mode and communication protocol at the application layer,and configures the parameters of the communication module.The results of the gateway function test show that the agricultural Io T gateway has achieved the expected goal of the design.The main research results of this paper:(1)In order to adapt to the characteristics of complex agricultural production scenarios and changing environments,this gateway provides support for Zig Bee,Bluetooth,Lo Ra and RS485 downlink communication methods,as well as Wi Fi and GPRS uplink communication methods.It can be pre-configured to meet the needs of users to flexibly select communication methods,and it has better versatility while ensuring the wide access requirements of gateways.(2)Aiming at the problem of complex adaptation protocols of agricultural Internet of Things gateways,a Kframe structure model is proposed as a bridge for the conversion between Modbus,Zig Bee,GSXY and LWXY protocols,and realizes the exchange of most gateway communication protocols on the market.After testing,it was found that the Kframe structure has excellent potential value compatible with new gateway communication protocols.(3)In order to ensure the security of the data transmitted by the gateway,an improved RSA encryption algorithm is used in the design of the agricultural Internet of Things gateway to encrypt the transmitted agricultural data,thereby further improving the security of the agricultural Internet of Things gateway. |
