Research And Implementation Of Clock Synchronization System Based On LoRa

In modern life,time is an indispensable reference.The main function of the clock synchronization system is to provide accurate time information.It has been widely used in airports,rail transit,universities,hospitals and venues.It provides people with time display services,and provides time synchronization services for many smart devices and informa-tion systems,making them work in unison and orderly.It is an important infrastructure.The current clock synchronization system has disadvantages such as high cost of the wired net-work,inflexibility and difficulty in later modification.The communication distance between Zigbee and WiFi and other technologies is short.It is difficult to meet the needs of long-distance time service.Based on the long-distance and low-power characteristics of LoRa,this paper uses a star topology to design a wireless long-distance clock synchronization system based on LoRa.This system is composed of STM32 series single-chip microcomputers and LoRa,combined with the core idea of sensor network time synchronization algorithm(Timing-Sync Protocol for Sensor Networks,TPSN)and Network Time Protocol(Network Time Protocol,NTP),which recognizes the round-trip time delay of synchronization messages equal.Designed a composite clock synchronization and management algorithm,improved the synchronization process and designed synchronization messages,which greatly im-proved the system timing accuracy.The state information of the clock terminal is added to the synchronization message to realize the management function of the clock source to the clock terminal.The clock source polls the clock terminal to solve the problem that it is difficult to synchronize multiple clock terminals.The clock terminal uses a digital tube to display time information.Aiming at the short circuit and open circuit failure of the digital tube,a digital tube diagnosis algorithm is proposed to realize real-time diagnosis,and a backup digital tube is designed.Once the digital tube fails,the backup digital tube can be activated without affecting normal use.The TLink Internet of Things platform is used to realize remote monitoring of the clock synchronization system.The parameters and alarm information of the clock synchronization system can be viewed in real time on the web and WeChat terminals,which improves the level of intelligence and automation,and achieves the effect of data query,real-time monitoring and automatic alarms.In different environ-ments,the two parameters of LoRa packet loss rate and Received Signal Strength Indicator(RSSI)are carried out experimental research.Analyzing the time synchronization accuracy of the system under long-distance conditions.Comparing the composite clock synchro-nization plus management algorithm with the broadcast clock synchronization algorithm in different environments in urban and suburban areas,the results prove that the composite clock synchronization plus management algorithm has a much higher timing accuracy than the broadcast clock synchronization algorithm.At present,the accuracy of obtaining time information on the Internet is low and unstable,so this article implements a small,flexible and economical NTP server based on the clock source.The synchronization accuracy can reach the microsecond level,which fully meets the requirements of use.This paper implements a LoRa-based clock synchronization system with simple struc-ture,flexible networking,and good operating conditions,which can meet the needs of large geographic companies or unit time synchronization,and has a high promotion value in prac-tical applications.