hackaday, If elevated CO2 levels have you worried, this friendly face might be just what you need.
https://hackaday.com/2024/03/19/cute-co2-gauge-tells-you-when-to-crack-a-window/
hackaday, If elevated CO2 levels have you worried, this friendly face might be just what you need.
https://hackaday.com/2024/03/19/cute-co2-gauge-tells-you-when-to-crack-a-window/