Build an Air Quality Monitor Using Just Three Components

Air quality has been on a lot of people’s minds since the pandemic started, as the virus attacks the lungs, making it tough to breathe. More so for those living in the western US, where forest fires are filling the air with particulate matter, such as fine ash. Those with lung problems like asthma, COPD (Chronic Obstructive Pulmonary Disease), emphysema, and lung cancer could find themselves in real trouble when the air quality drops.

To help keep tabs on the surrounding air quality, maker Michael Winter designed a wearable air quality monitor that displays particle count and temperature, all in a tiny package. His build uses only three components: an Arduino-compatible board from STMicroelectronics, an LCD screen, and a Honeywell HPMA115S0-XXX sensor. The sensor is the star of the show and comes equipped with a fan that draws air passed a laser that counts particulate matter as it’s drawn through a tiny duct.

The device works by engaging the development board, which transmits a code to the sensors to begin checking for particles with the surrounding air. The sensor then sends the collected data back to the Arduino, which processes the data, and then shows the results on the LCD display. Winter modified a Pelican case to serve as an enclosure for the board, sensor, and power bank, while the LCD is affixed to Velcro straps that can be worn on the wrist.

Winter's air quality monitor is more on the bulky side and could benefit from a more streamlined design. Still, it is useful and very inexpensive to replicate, more so if users already have most of the components on hand. It could also assist those with respiratory illnesses vacate the area before the air quality becomes worse.