Large Building Indoor Environment Monitoring System Based On LoRa

With the continuous improvement of living standards,people are increasingly demanding the intelligence of living environment and workplace,and intelligent buildings have gradually become the development direction of future buildings.In order to meet the needs of intelligent building and indoor environmental monitoring technology development,this paper uses LoRa communication as carrier,combined with GPRS communication technology,sensor technology and embedded technology to design a large building indoor environment monitoring system based on LoRa,which realizes large-scale Real-time monitoring of building temperature,humidity,flammable gas concentration and control of indoor electrical equipment.The overall architecture of LoRa-based large building indoor environment monitoring system consists of business layer,network layer and application layer.As the business layer of the system,the collection node is equipped with DHT11 temperature and humidity sensor,BH1750 FVI light intensity sensor and MQ-2 smoke sensor to measure the indoor temperature and humidity,light intensity and flammable gas concentration.Stepper motor and relay are also installed.Used to control curtains and lighting.The network layer includes the aggregation node and the relay node,and both use STM32 as the main controller,and the LoRa module is used to implement data forwarding,packing,and aggregation.In addition,the convergence node hardware circuit also includes a GPRS module interface circuit and a serial communication circuit to implement data package uploading,and the application layer adopts a dual mode display mode,including a computer host computer display and a mobile APP display.The computer host computer display program is developed by LabVIEW software,and the data of temperature,humidity,light intensity and flammable gas concentration in the field are displayed by means of digital direct display and graph.The sound and light alarm can be exceeded beyond the preset threshold to realize real-time monitoring and alarm.The function.In order to detect the environment inside the building by using portable devices such as mobile phones,the system develops the mobile client APP software by using Android Studio development software,and communicates with the server by using TCP/IP protocol to realize real-time display of monitoring parameters,and can also be used for buildings.Users can also use the mobile APP to control the curtains and lighting in the building.Tests and data analysis of system functions,communication distances,and power consumption of communication modules were carried out in large buildings.The experimental results verified the integrity of the system functions,the friendliness of the interface,and the stability of communication.