This short tutorial shows how to build simple CO2 meter using CJMCU-8118 board and Raspberry Pi 3. This board uses CCS811 sensor. This sensor supports intelligent algorithms to process raw sensor measurements to output a TVOC value or equivalent CO2 (eCO2) levels, where the main cause of VOCs is from humans.
CJMCU-8118 includes HDC1080 sensor. There is also list of available alternative boards with CCS811 sensor on the end of this video.
An interesting link found among my daily reading