[getwiththeprog]

You could buy a Bosch BME680 or similar for $20 and add it to a Pi or Arduino.

A commercial model is around $200.

There are a lot of options so decide if you want to build it or buy it and plug it in!

Then you can list your data on a site like https://explore.openaq.org/

[tlavoie]

The BME 680 does temperature, humidity, barometric pressure, and VOC gas sensing. Maybe there's something reasonably-priced that does particulates, but this doesn't seem to be it. What's a good alternative?

[Eisenstein]

https://www.adafruit.com/product/4632

[tlavoie]

That looks awesome, thanks! I already have some ESP32 devices acting as weather sensors that log to a Raspberry Pi over MQTT. I might have to add this too.

[throwaway2037]

Very impressive. I looked up that Bosch device: https://www.bosch-sensortec.com/products/environmental-senso...

Then, I found a board from Adafruit. The chip is so tiny in the Adafruit photo!

https://www.adafruit.com/product/3660