Development of low power consumption manhole cover monitoring device using LoRa

Aiming at the problems of damage, loss and displacement of municipal manhole cover, an on-line monitoring device of manhole cover condition using LoRa wireless communication technology is designed and developed. The ADXL345 accelerometer sensor is used to monitor the manhole cover condition and Lora is used for long-distance wireless transmission. First, the working principle and overall structure of the system are introduced. Then, considering the communication distance and low power design of the equipment, the hardware design and software design of the field-end monitoring device are mainly introduced, including RF enhancement, antenna optimization, low power IO configuration and adaptive power algorithm. According to testing and analysis, the reliable communication distance of the monitoring device is 600 meters, and the battery life is over 3 years, which fully meets the requirements of high efficiency and low cost of digital municipal manhole cover supervision.