[scottlamb]

> Unfortunately, when I last looked, I couldn't find any consumer-grade sensors which used dual-NDIR sensors, only more expensive and less aesthetic commercial sensors. In the end I built my own using a CDM7160 sensor connected via I2C to a ESP8266, which reports over MQTT.

Looks like that's been discontinued. [1] Any advice for folks trying to build one now?

[1] https://www.figarosensor.com/topic/2020/11/Discontinuance-of...

[abirkill]

That's a shame, they've worked well for me. Unfortunately I can't recommend any others without doing some research, I found quite a few dual-NDIR sensor modules when I was looking and chose this one primarily based on availability and a reasonable datasheet.

A sibling post[1] mentioned a sensor that is listed as being dual-NDIR so should give reliable readings, and has a USB interface, so that sounds like one possibility.

[1] https://news.ycombinator.com/item?id=32122301

[alins]

Manual for this unit is at https://cdn.shopify.com/s/files/1/0019/5952/files/Manual-RAD...

I assume 'dual-beam' is the same as dual-channel? Does the calibration technique mentioned in the manual indicate dual channel operation?