The goal of this project is to create air pollution sensors that are powered by the magnetic fields emitted from power lines. This energy will be collected using a magnetic energy harvester being designed in Professor Olsson’s laboratory. These low maintenance sensors can be deployed on telephone poles all around a city so that anyone can have an accurate idea of the air quality around them. We begin by targeting carbon monoxide, as it is a harmful gas emitted from vehicles, smokestacks, and factories.
The sensor measures carbon monoxide in the air once every five minutes and transmits the data once per day over LoRa, a low powered transmission protocol, if there is any change in air quality. As the power harvested from magnetic fields is in the order of hundreds of micro-watts, the main challenge of this project is to design the system to efficiently use the energy we have available. All our components, including the sensor, MCU, LoRa chip, and energy harvester, are chosen to stay within this power budget and therefore extend the life of the project.
We designed and soldered a custom PCB that connects all the separate components together and wrote firmware that dictates sensor data collection and LoRa communication to our MQTT server at the Aexonis base station in Pennovation. Although we were not able to integrate all the parts of the final project together in time, we have each subsystem tested and working.