Design And Realization Of Mobile Ambient Air Quality Detector

With the deteriorating air quality resulted by gradually intensifying urbanization, China’s air pollution type has transformed from coal-burning pollutions to a mixed and severe type, with coal, vehicle exhaust, and industrial discharges. Air pollution has aroused people’s high-level attention. Although the Internet makes real-time air quality data accessible to the public, this information is limited to several individual monitoring points across the city. The ambient air condition of any person is still unavailable. Therefore it is necessary and pressing to develop a portable device that monitors the concentrations of six air contaminants.This thesis analyses the air quality situation in domestic cities and abroad, and theoretically studies the methods for detecting contaminant concentrations and for calculating AQI. A systematic plan for the design has been then established. Next, the hardware system has been established. Major components of the device, including a MSP430F149SCM, six sensors, an FM12864-12L dot-matrix LED, an LED alarm, a serial communication module and a battery module has been described. Type selection of the components has been discussed. Circuit design has been then completed. Based on IAR Embedded Workbench software development environment, functions including data and processing, user control, digital display, over limit warnings, data storage, history searching, and upper computer communication have been successfully designed. Data communication between modules has been established. Finally, a simulated verification using PROTEUS simulation platform has been run for all functions and detection precision has been checked and calibrated. System stability has been improved.Through repeated testing and calibration, the portable air quality monitoring device has met all design requirements. It is able to display real-time indexes of PM2.5, PM10, O3, CO, NO2and SO2, calculate AQI values, and provide health advices to users. It features portability, USB connection, warning, data storage and transfer. Products based on this design have a sizable market and relatively high values for daily usage.