Seems similar to the SCD40 photoacoustic approach.
I used that for an open-source CO2 monitor I designed:
I used that for an open-source CO2 monitor I designed:
We at AirGradient open sourced our monitors around 2 years ago and this has been the best decision for our company.
BTW Your "Advanced ESP32 development with ESP-IDF" guide [1] is the best "getting started" guide I've seen so far. Up to now no guide has been so clear and complete, and I've spent one week being very frustrated by how confusing the official ones are.
So thank you again. You made me rekindle the spark of creativeness that got buried by age and daily grind.