Design And Application Of Smart Home System Based On Bluetooth Mesh And NB-IoT

With the rapid development of communication technology in recent years,the 5G era has come,so that the "Internet of Everything" can become a reality,and the Internet of Things technology can be more comprehensive and rapid development.The intelligent devices related to the Internet of Things have become more and more widely used in people's daily life,and smart home devices are increasingly favored by people,bringing further life improvement to human beings.Therefore,this paper designs a smart home system based on Bluetooth Mesh and NB-IoT.Its main work is as follows:First,for the Bluetooth Mesh network,the flooding algorithm is currently used to cause a problem of low transmission efficiency when the number of nodes is large.In this paper,a broadcast algorithm based on signal strength is proposed.The algorithm calculates the node coordinates by signal strength,and then selects the next forwarding target node through the optimal coverage model,which effectively reduces the forwarding node while ensuring the delivery rate.Number and number of forwards,suppressing redundant packets and reducing collision retransmissions as much as possible.Second,for the current wireless Mesh network topology is single,each node is a transit node and requires real-time scanning of message packets from neighboring nodes,resulting in the problem that the Bluetooth device cannot perform low-power networking.This paper proposes an improved Bluetooth Mesh network topology,which adds friend nodes and low power nodes,and solves the problem of limited Bluetooth communication distance and low power consumption networking.Each node in the Mesh network is combined with a Bluetooth 5.0 module with the ultra-low-power SoC chip nRF52832 from Nodic,which forms different Mesh network node types.Third,for the smart home industry standards are not uniform,product incompatibility,networking requires WiFi network and complex network configuration and other issues.This paper firstly designs a smart home controller gateway based on Bluetooth Mesh and NB-IoT.It uses ARMCortex-M3 processor and uses open source uCOS-II operating system to design a StemWin-based GUI interface on the LCD touch display.It is convenient for human-computer interaction and can monitor and control smart home network nodes.The NB-IoT module in the controller gateway can directly interface with the telecom IoT cloud platform,without the need for WiFi network and network access configuration,enabling users to monitor and control different smart home products of different vendors through the IoT cloud platform.Fourth,the function and performance test of the entire smart home system,and analysis of the results,preliminary verification of the feasibility of the program.