Design Of Farmland Environment Monitoring System Based On LoRaWAN Internet Of Things Technology

With the development of the Internet of Things in all areas of the world,it is especially important to study the communication technology that is more in line with the Internet of Things and to realize it in the product of the Internet of Things.In the agricultural internet of things,in order to monitor the environmental parameters of farmland in various locations in real time,traditional agricultural internet of things generally uses ZigBee,WiFi and other communication protocols.However,with the increase of farmland area and access nodes,it is needed to meet the requirements of large access volume,low power consumption,and long distance at the same time.In order to solve the problems above,the adoption of LoRaWAN(low power long range WAN)communication protocol and LoRa spread spectrum modulation technology can achieve the effect of stronger anti-jamming capability,longer communication distance,lower power consumption,and multiple access volume.According to the application requirements of farmland monitoring,analyzed the key technologies and difficulties of the farmland monitoring system based on LoRaWAN Internet of Things technology,also designed and implemented the structural composition and overall plan of the entire farmland monitoring system.Aimed at the actual situation of large-scale outdoor farmland,a high-gain antenna with a longer communication distance and a more power-efficient LoRa working mode have been designed.It was determined that the operating frequency of LoRa communication is a free public 433 MHz-470 MHz and 868 MHz frequency band.The gateway and node hardware circuits for farmland environment were designed,and the working principle and key technologies of the whole system were analyzed.Combines the LoRa communication system with the sensor network and the farmland environmental monitoring system,and uses different bus communication methods for different sensors to transmit data.The gateway uses Raspberry Pi3 as a computation module,four or eight channels of SX1278 as the LoRa communication chip,and 4G,Ethernet,and Wi-Fi as the gateway and server communication scoring methods.Node uses low-power MCU-EFM32G222F128 as the main control,the ordinary lithium-sulfur battery for power supply and SX1278 as a communications chip,linked to sensors through the bus such as IIC,SPI,one-wire and etc.The database adopts MySQL and the data display part and the system management platform are realized by WEB.The designed and debugged of hardware of the farmland monitoring system and the code preparation of the software,and the hardware was made to build the entire farmland monitoring system.System stability test,communication distance test and power consumption test were also carried out.The reliability and applicability of the farmland monitoring system with LoRa technology was verified,and the effectively improve measures were put forward to solve existing problems.In combination with the farmland environment monitoring system based on the traditional wireless network,the advantage and the general trend of the future development of the application of LoRa IOT technology in the farmland environment monitoring system was analyzed.