Design Of Indoor Environment Monitoring System Base On Multiple Sensors

Nowadays,indoor air quality is directly related to people's health.Therefore,the equipment of indoor air quality testing has gained a great market in recent years.At present,the traditional indoor environment monitoring instruments commonly exist many shortcomings.Such as single-function,bulky and single objectives detection which can not fully measure the indoor environmental quality.At the same time,most indoor gas detection instruments ignore the problem that the gas sensor is vulnerable to cross-interference caused by other gases,which greatly reduces the detection accuracy of detection equipment.In order to solve the current lack of indoor environmental testing equipment,this paper developed a set of indoor environment monitoring system based on multiple sensors.Indoor environment monitoring system choose the 32-bit microcontroller STM32F407ZGT6 as the system's core controller based on the Cortex-M4 core architecture of.The sensor array consisting of PM2.5 sensor,formaldehyde sensor,carbon monoxide,carbon dioxide,oxygen,temperature and humidity sensors is used as the data acquisition node of the system.Liquid crystal display module,voice alarm module,real-time clock module are regarded as a secondary function of the system.The main control chip STM32F407ZGT6 controls the operation of each peripheral module and analyzes,processes,stores,displays and wirelessly transmits the data uploaded by each sensor node.The added remote monitoring function enables communication between the mon itor and the host system software.The design of the software includes embedded software development and PC software development.Embedded software development mainly compiles the communication drive between the sensor array and the master chip,the displa y driver of the liquid crystal display,the data transmission driver of the Wi-Fi module,and the interrupt handling functions.PC software development mainly realized Socket network programming based on TCP protocol,which enabled the host computer software to acquire the factor concentration which from the indoor monitoring transmitted by the Wi-Fi module.At the same time,the interface of the system software is designed based on the Qt interface development framework,and the data reception and data display are synchronized through multi-thread task scheduling and synchronization mechanism.Users are able to log on the software to remotely view the air quality of their environment in real time so that they can timely make measures to make room clean.In order to solve the problem of low measurement accuracy because of cross gas interference,this paper uses BP neural network algorithm and multivariate function fitting algorithm to improve the accuracy of measurement data of monitoring system.Finally,the paper tests the stability of the system and the data measurement accuracy.The results show that the indoor environment monitoring system developed in this paper has achieved the aims of multi-factor monitoring,remote monitoring,multi-function and establishing portable monitor.