A Power-Efficient Environmental Monitoring Station for Evaluating Low-Cost Sensors in Uganda

Abstract

Low-cost environmental monitoring devices offer an elegant solution to facilitate wider adoption of environmental monitoring in various fields of application. These devices are majorly based on low-cost sensors whose consistency and reliability needs to be assessed in comparison with the existing industry standards. To address this, a research project was done to establish a framework for data collection and analysis needed to evaluate the accuracy, consistency and reliability of these sensors. As part of this project, an en- vironmental monitoring station for evaluating and comparing these sensors was designed and deployed at the Makerere weather station. This node comprises eighteen individual sensors, categorized into six different types. Among these types, four are temperature and humidity sensors while the other two are air quality sensors. It is planned that this node will be deployed in different areas in Uganda to expose the sensors to different conditions and select the best performing sensors for deployment across the country. However, the current node is powered by a 100Ah battery charged by two 80W solar panels connected in series. This is very power intensive and does not lend itself to wide deployment. In this project, the hardware and software aspects of the existing system were redesigned to reduce power consumption and make it more cost-effective for deployment on wider scale. To achieve this, the existing system was assessed particularly the circuit board and its components, the currently used microcontroller was compared with other microcon- trollers in search of one with more low power features and through the embedded system development process a power-efficient environmental monitoring system was developed. This system is powered by a 5Ah battery charged by a 5W solar panel.