Indoor Environmental Quality Detection And Alarm System

Since the reform and opening up,China's economy has been developing at a rapid pace,but the ensuing environmental damage and pollution problems have become increasingly prominent.Although the state attaches great importance to environmental issues and has invested a lot of manpower,material resources and financial resources to manage it,the environmental problems are still grim.At the same time,today's technological development has made people spend more time indoors,so it is increasingly important to effectively monitor and warn indoor sanitation.Therefore,it is of great significance to design an indoor environmental quality inspection and alarm system that is flexible,convenient,practical and comprehensive.This thesis designs indoor quality inspection and alarm system through analysis and research on existing environmental quality inspection technology and embedded server technology.The system design is divided into two parts: sensor data acquisition and its alarm part and remote query part of the embedded server system.Detection objects of the sensors include temperature,humidity,atmospheric pressure,light intensity,particulate matter concentration,carbon dioxide concentration and formaldehyde concentration.The real-time operating system technology is applied to the STM32F103ZET6 microcontroller,which can realize the multi-task parallel operation function of transmitting data to the server through nRF24L01+ while detecting multiple detection objects.When the detected object exceeds the system threshold,it will use SIM800 C to send an message to remind users to improve the indoor environment quality in time.In order to improve the practicability of the system,this article uses the S3C2440 A application processor to build the Linux operating system and run the thttpd server.The server system drives the underlying hardware through the Common Gateway Interface(CGI)technology,and the data transmitted through the nRF24L01+ module is converted and fed back to the web browser in real time.The server system uses asynchronous JavaScript and XML(AJAX)technology,so that the server system and the web browser can realize the automatic refreshing of the web page data only by performing a small amount of data exchange,thereby ensuring the real-time performance of the server system data.The experimental results show that the system design can collect temperature,humidity,atmospheric pressure,light intensity,particle concentration,carbon dioxide concentration and formaldehyde concentration data in real time and display it on the LCD screen.The data is transmitted to the server system through the wireless radio frequency technology.The user can access the homepage of the server system through the web browser to see the dynamic data trend graphs related to indoor environmental quality.The system has the advantages of high reliability,long transmission distance,flexible use,etc.The system design meets the requirements of indoor environmental quality detection and alarm,and has good practical application value.