Design And Implementation Of Low-power Aquaculture Water Quality Monitoring System Based On LoRa

Along with the rapid development of domestic aquaculture industry,the area of aquaculture has increased year by year,which has become one of the major industries for agricultural economic growth in China.However,in the monitoring of aquaculture water quality,most farmers still adopt traditional farming models that rely on artificial experience,which cannot make scientific judgments on water quality and affect the development of the industry.At present,with the rapid development of agricultural modernization and wireless sensor network technology,it provides a scientific solution for aquaculture water quality monitoring.Nowadays,most of the industrial aquaculture water quality monitoring uses Zigbee,Wi Fi,GPRS and other wireless communication technologies to communication,but for the pond aquaculture area with large monitoring area,there are shortcomings such as short communication distance,poor anti-interference and high power consumption.Based on the development needs of aquaculture water quality monitoring,this paper applies low-power WAN Lo Ra wireless communication technology to design a low-power aquaculture water quality monitoring system based on Lo Ra technology.The main contents of this paper are as follows:(1)According to the requirements of the actual application scenario,compare and analyze several common communication technologies of low-power local area network and low-power wide area network,and combine the characteristics of Lo Ra technology,the technology is applied to the design of aquaculture water quality monitoring system to determine the overall architecture of the system.(2)Analyze the system requirements,determine the hardware design part of the system,and include hardware solutions of sensor nodes and aggregation nodes.The sensor module,the main control module,the wireless communication module and the power module together constitute sensor node,the sensor node collects the waterIV temperature and the PH value through the sensor downward,and sends data to the aggregation node upward using the Lo Ra wireless technology.The aggregation node not only needs to communicate with the sensor node,but also needs to aggregate the data and transmit it to the host computer through the serial port.(3)In the aspect of embedded software development,the IAR integrated development environment is used to design applications for sensor nodes and aggregation nodes.According to the requirements of aquaculture and the requirements of controlling production cost,two parameters of water temperature and PH value which have great influence on water quality were selected,the analog signal output by the sensor is converted into digital signal,the data are packaged and the communication function of sending and receiving is completed,at the same time,the communication between the system and the host computer is realized.(4)In the development of PC software,a PC-based monitoring platform with friendly interface is completed by using Visual Studio 2015 development environment and C# language,the data received through the serial port is graphically displayed,the water quality parameter information collected by each sensor node is monitored in real time,the fluctuation of water quality parameters is visually displayed,and the water quality parameter database is established,which can view the past historical data and set the warning value for the operator to view and analyze.(5)Through the analysis of the factors affecting the system power consumption,it is concluded that the purpose of reducing the power consumption of the system can be achieved from the two angles of hardware and software.The hardware part selects the SX1278 RF chip based on Lo Ra communication technology and the STM8 L microprocessor as the main control to ensure the system has low power consumption.The software part first uses the power control technology to select the appropriate transmit power according to the size of the monitored area to reduce the power of the system.Secondly,the Lo Ra MAC communication protocol based on TDAM protocol is designed for the collision of energy consumption caused by the competition channel during system communication,it avoids the conflict between nodes and increases the sleep time of nodes in the working period.(6)The simulation test of the aquaculture water quality monitoring system includes system communication distance test,power consumption test and functional test.The test results of communication distance show that the packet loss rate is less than 10%,and thecommunication quality is good when the monitoring range is within 2 km;The service life of the node can reach 9409 hours when the working period is 10 minutes and the battery capacity is 2800 m Ah;The system uses the star networking mode and Lo Ra MAC communication protocol to build a wireless network.The upper computer interface indicates that the system functions normally and meets the expected design goals.In summary,the system tests meet the design requirements,the system has the characteristics of low power consumption,long-distance transmission,flexible node placement and so on,it has good development prospect in the field of aquaculture water quality monitoring.