A coupld years ago we had horrible air quality in San Francisco. I got tired of checking the PurpleAir site and instead wanted a passive way to just see the air quality outside. So I sat down and designed and built a PCB to show it. It pulls data from my PurpleAir on my roof (via their API).
I wanted to share this to see if anyone is interested in this – here is my write-up and a demo video: