Skip to main content


Showing posts from September, 2019

Arduino air quality sensor

After some facade renovations, some of the air vents in some residents in the condominium I live in have complained about bad air quality. I have not noticed any changes but thought that it would be good to check if the air quality in my apartment is acceptable. The commercial CO2 monitors are rather expensive, so I decided to build my own with the Arduino I already own and with an inexpensive analog gas sensor MQ-135. With a few lines of code, the monitoring was set-up by getting an average reading of the air quality sensor in one-minute intervals. The Arduino sends the measurements via serial port to my computer, which then creates a CSV file of the result with a python script.