Research On Air Quality Monitoring Wireless Sensor Network Terminal Integration Technology

In recent years,China's environmental damage has become increasingly severe,especially in northern industrial cities in China,where the proportion of winter haze is increasing.At present,China's air pollution situation is relatively serious around the world,and the treatment of environmental air quality problems must be urgently resolved.The first step in the protection and management of ambient air quality is to achieve air quality monitoring.Only by accurately monitoring and understanding the air quality can the corresponding governance measures be effectively carried out.Therefore,this paper analyzes the development and research status of air quality monitoring systems at home and abroad,synthesizes the existing atmospheric air quality monitoring systems,and designs a multi-sensor integrated air quality monitoring system based on this.The system adopts the master-slave design mode,and the data acquisition terminal polls the integrated multi-sensor design scheme through the ModBus-RTU protocol,which increases the number of sensor accesses and has both analog signal sensors and digital signal sensor interfaces.The sensor data processing uses a combination of limiting filtering and sliding window filtering to perform compound filtering on the sensor collected data to filter out high-frequency outliers and low-frequency outliers of the sensor data in real time.It ensures the smoothness of the sensor data without changing the volatility of the data.The data acquisition terminal uses NOR Flash as the data cache unit.According to the read and write characteristics of NOR Flash and the business requirements of the data cache of the acquisition terminal,the idea of a circular buffer is integrated into the design of the flash read and write driver to achieve the first-in-first-out data cache characteristics and optimize the flash memory driver.Effectively improve the service life of the memory.In combination with this caching scheme,a service quality guarantee mechanism for data upload is implemented,ensuring that the server receives the data uploaded by the terminal at least once.Reduce data loss caused by irresistible factors such as network anomalies or server failures.The system takes STM32 monitoring terminal as the core,completes the design of multi-sensor integration,and realizes the collection of air quality data of integrated sensors,including15 sensors such as temperature and humidity,CO₂,SO₂,NO,O₃,CO and so on.And upload the data to the cloud server through the 4G wireless communication module in real time.