Design And Fabrication Of A Microcontroller Based Carbon Monoxide Monitoring And Mapping System Using Gps Technology

ABSTRACT

Air pollution is a major factor of consideration in the evaluation of quality of life and as an environmental issue in urban areas. Among the urban air pollutants, carbon monoxide (CO) is one of the most prevalent and having serious health as well as environmental effects. The availability of accurate information about its concentrations, variations and location is vital in the determination of urban air pollution. A number of devices for carbon monoxide monitoring have been designed. The devices measure CO concentrations and energize a visual and audio alarm when the levels exceed safe limits. However they only give data points of CO levels but do not provide information about the when and where it was measured. They also lack mechanism for data transmission. To address this shortcomings this research has designed a portable microcontroller based CO monitoring system which incorporates a GPS receiver to provide location information where the data is collected. The system is made up of sensors, interfacing circuits, a GPS receiver, a GSM modem, the software and the PIC18F45K22 microcontroller. The input part has the TGS2442 sensor for measuring CO and DHT11 sensor for humidity and temperature. The TGS2442 has been interfaced to the microcontroller through an analogue to digital converter module. A GPS receiver has also been interfaced to PIC18F45K22 to provide time, longitude and latitude where the data has been collected. The output comprises of the LCD for local display while the GSM modem for transmission of the collected data as a short text message. The GPS receiver and GSM modem have been interfaced to PIC18F45K22 through the EUSART module. The controlling software has been designed in C programming language in conjunction with attention (AT) commands. Finally the system has been tested by monitoring CO levels in different environments. At a rural place in Erusui village, Vihiga County CO levels ranged between 2.5 – 4.0 ppm while in a site in an urban area at Kenyatta University, Kiambu County it was between 5.5 – 6.0 ppm at different times. In a room with burning charcoal CO in the range of 35 – 46 ppm were recorded. The GPS receiver provided the latitude, longitude and time when the data was collected.Therefore the designed system is able to monitor carbon monoxide concentrations, give the time and location information where the data was collected.