The application of LoRa technology to realize the long-distance wireless transmission scheme of water meter reading

LoRa is one of the LPWAN communication technologies, and it is an ultra-long-distance wireless transmission scheme based on spread spectrum technology adopted and promoted by Semtech in the United States. This solution changes the previous compromise between transmission distance and power consumption, and provides users with a simple system that can achieve long distance, long battery life, and large capacity, thereby modbus tcp gateway expanding the sensor network. At present, LoRa mainly operates in free frequency bands around the world, including 433, 470, 868, 915MHz, etc.

The above three pictures are all LoRa modules from Chengdu Ebyte Electronic Technology Co., Ltd. The LoRa module is an ultra-long-distance wireless transmission scheme based on spread spectrum technology. This solution changes the previous compromise between transmission distance and power consumption, and provides users with a simple system that can achieve long distance, long battery life, and large capacity, thereby expanding the sensor network. LoRa technology has the characteristics of long distance, low power consumption, multi-node, and low cost. LoRaWAN-based network can provide secure data transmission and long-distance two-way communication, and cover urban areas with the least network infrastructure. LoRa technology is used in smart agriculture, It will be widely used in various application scenarios such as smart buildings and smart logistics.

This paper designs a wireless water meter reading system based on LoRa communication, which has high accuracy, wide adaptability and practicability. The wireless water meter reading system designed in this paper can be divided into three parts: water meter, repeater and concentrator according to the different functions realized by each device. The main functions of the water meter are forward flow statistics, reverse flow statistics, magnetic interference detection, emergency shutdown Valves and wireless data transmission; the main function of the repeater is to transmit and receive signals to distant water meters; the main function of the concentrator is to receive workstation instructions, manage the water meters, and collect and upload data.

The LoRa module of Chengdu Ebyte is used in the design, which is embedded with high-speed and low-power single-chip microcomputer and high-performance LoRa spread spectrum chip SX1278 SX1276. The LoRa communication technology of SX1278 SX1276 chip can solve the problem that the signal of ordinary wireless communication technology cannot be solved in modern buildings. The problem of penetrating the floor and copying to the water meter in the high building, and SX1278 and SX1276 have low power consumption mode and sleep wake-up technology, combined with the design of hardware and software, so that the battery-powered water meter and repeater can maintain ultra-low power consumption, solving It solves the problem of short standby time in wireless meter reading. The communication protocol in the design is improved on the basis of the wired meter reading protocol combined with the functional requirements of wireless meter reading.

LoRa communication is used between the water meter, the repeater and the concentrator, which is mainly used for the concentrator to read the data in the water meter. When the concentrator receives workstation commands and uploads data, it adopts GPRS communication. When the workstation needs to read the meter, it sends the meter reading instruction through GPRS, the concentrator sends the meter reading instruction to the water meter through LoRa communication after receiving the instruction, the water meter returns the ethernet to rs485 adapter data to the concentrator after receiving the instruction, and the concentrator then returns the received data to the water meter. Workstation, so as to realize the process of wireless meter reading.

Compared with traditional water meters, smart water meters using LoRa technology can accurately and quickly collect and record real-time water consumption data of residents, improve work efficiency and ensure service quality. During the peak period of water consumption, the user's water consumption information system can comprehensively monitor and balance the water consumption in the region, thereby effectively guaranteeing the production and living water of enterprises.