ADPD188BI - Application for CO2 Measurement

A lot of effort went into this Circuit Note on CO2 sensing:

https://www.analog.com/media/en/reference-design-documentation/reference-designs/cn0338.pdf

which is based on IR irradiation, but which uses thermopiles instead of photodetectors to sense

the IR (and thus, isn't directly applicable to a smoke-detector module like the ADOD188BI). 

But the Circuit Note does explain the sensing physics in detail, so it could be good background

reading to evaluate doing a design that senses the IR using photodetectors. Good luck,

Thank you john-lazzaro for this resource. I will check it out.

No, CO2 detection with the ADPD188BI is not possible.  C02 absorbs primarily at an IR wavelength with peaks at 2um 2.7um and 4.3um.  The IR used in the smoke detector is 880nm or 0.88 microns.  the ADPD188BI uses a silicon detector.  Silicon becomes transparent above 1um.