[alvern]

For the hackers out there, you can record CO2 with a K33 sensor. The [0] Livpi uses this chip.

EDIT: it appears the Livpi uses a K30 chip. The K33 [1] is the version sold on industrial sites.

[0] http://www.livpi.com/ [1] https://www.co2meter.com/products/k-33-icb-co2-sensor