| In recent years,with the continuous advancement of China’s industrialization,the demand for energy is increasing day by day,but the huge energy consumption has also brought serious air pollution problems,among which the problems of dust,particulate matter and toxic and harmful gas pollution are particularly prominent.Excessive concentration of dust and particulate matter will cause haze and affect people’s production and life.All kinds of poisonous and harmful gases can cause a variety of respiratory tract and cardiovascular and cerebrovascular diseases,which have an impact on human health.In order to deal with the prevention and control of air pollution,it is necessary to monitor air pollutants.At present,local environmental monitoring mainly relies on the air quality data released by the state-controlled monitoring stations.Monitoring sites in different countries are far away from each other,so they can only detect the overall environmental quality within the monitoring area,which cannot meet the outdoor detection requirements for specific scenes at the present stage.At the same time,the construction cost of national monitoring sites is high,and the selection factors are complicated.In this case,the development of a high precision,high portability,low cost,miniaturization and easy to install the micro outdoor air quality testing equipment has practical value and economic value.This paper designs based on multi-sensor air quality testing equipment,hardware design with NXP MK64FN1M0VLQ12 chip as the processing core,design related peripheral circuit,including power management circuits,minimum system circuit,temperature and humidity detection circuit,gas detection circuit,wireless transmission circuit,LCD display circuit,as well as other auxiliary circuit.In terms of software design,the corresponding software system design and algorithm are given according to the design objectives.This system can comprehensively detect CO,SO2,temperature and humidity and particulate matter in the outdoor air.The relevant information is stored in SD card and displayed on LCD screen.This system uses Bluetooth to send the information to the intelligent terminal,which is convenient for people to know the current outdoor air quality in real time.In addition,the design of voice alarm module,can be in the environment information value exceeds the set value when the alarm.In this paper,an independent gas chamber unit is designed,which can effectively reduce the cross gas sensitivity between gas sensors and improve the detection accuracy.After the software and hardware design of the system is completed,the hardware and software testing of the equipment and the output performance analysis of the sensor are carried out.Then,the air quality testing equipment is tested and analyzed by comparing the data with the test value of the state-owned testing station to verify that the equipment can achieve the design goal. |
