DIY Environmental Monitor

Early on in the pandemic, there was a good amount of discussion on Twitter about indoor CO2 levels as more people were spending time exclusively at home, often in a single, small room for hours on end. Since I was one of those people spending nearly the entire day in a single room, I decided to look around for a CO2 monitoring system. While a simple “alert after levels rise above x ppm” is sufficient, I was really looking for one that would be able to log data to a remote system so that I could monitor it throughout the day and/or look back on historical data from any computer. After being thoroughly disappointed with what was on Amazon (nothing at a reasonable price point seemed to be able to send data to a remote server), I decided it would be a nice little project to build my own.