Research On Greenhouse Environment Monitoring System Based On LoRa

With the rapid development of Internet of Things(Io T)technology,greenhouse monitoring technology has been given new power by Io T technology.Greenhouse greenhouse has the feature that it is not easily restricted by season and climate,and can be used for agricultural production under severe cold and heat,providing people with a large amount of anti-seasonal food.Therefore,greenhouse greenhouse monitoring technology is increasingly becoming an important direction for agricultural production research.At present,a large number of greenhouse monitoring systems use wired communication methods or traditional wireless communication methods such as Wi Fi(Wireless Fidelity)and Zig Bee,which have problems such as complex networking,difficulty in power supply,high power consumption and cost.In this paper,we propose a LoRa-based greenhouse monitoring system based on the advantages of LoRa(Long Range)technology which can be self-organizing network,low power consumption and low cost.The main research contents are as follows.(1)According to the requirements of the subject,this paper researches the low-power design strategy of microcontroller and designs the monitoring node,wireless communication node and concentrator in the greenhouse monitoring system.The greenhouse monitoring module completes the development of LoRa communication-based greenhouse environment monitoring node and concentrator.The monitoring node is powered by lithium battery and equipped with photovoltaic power generation circuit,which solves the problems of difficult wiring for greenhouse deployment and inconvenient battery replacement for wireless sensors.In order to ensure the low power consumption performance of the monitoring node,the method to reduce the power consumption of the monitoring node is proposed in the hardware design and software design of the microcontroller.(2)According to the requirements of the topic,this paper designs a greenhouse monitoring software based on EMQ message middleware and Spring Boot and Vue framework.The software realizes the real-time query and historical data display of monitoring data and remote monitoring of greenhouse controller.(3)According to the demand of the subject,this paper designs a wireless communication node based on LoRa spread spectrum communication,which connects the water and fertilizer machine that does not have wireless communication capability to the monitoring platform,and then realizes the remote control of greenhouse environment.(4)According to the above design objectives,this paper designs a LoRa low-power networking method combining TDMA(Time Dicision Multiple Access)protocol with mixed distribution and LBT(Listen Before Talk).The communication time slots of monitoring nodes are allocated in a fixed way,and the communication time slots of wireless communication nodes are allocated in a dynamic way,detecting the channel state at the beginning of each communication time slot,backing off when the channel is busy,and sending data when the channel is idle,realizing the time-sharing of uplink and downlink in LoRa network,and also allocating different time slots for each node’s data uplink,and ensuring the nodes to operate at a low-power level when they are not The low-power wake-up function ensures that the nodes operate with low power consumption in non-self time slots,which effectively avoids the problem of co-channel interference in LoRa networks and reduces the power consumption of the nodes.Finally,the system performance is tested,and the tests include LoRa communication distance,LoRa networking and monitoring the low-power consumption level of nodes.The experimental results show that this system has high reliability of LoRa networking and 4G communication,accurate data collection,low power consumption level,and can operate stably for a long time,which is a reference value for LoRa technology applied to smart agriculture.