Good exercise but FYI ESPHome is probably the way to go for most people.

All the sensors you mentioned are likely already supported and just need to be added to a yaml file.

I didn't know about this. I'll definitely check it out. Thanks!

Also look at the failure time and make sure you are sleeping correctly when not reading. esphome has this implemented and it is really great, it wakes up 10 seconds early, starts the fan/airflow, then takes the reading, then sleeps (for 50 seconds) in my case where I want to sample every 1 minute. Without this the lifetime of the sensor is around 1 or 1.5 years of continuous use if I recall correctly.

Even as an experiment with the sole purpose of learning stuff and having fun I find Arduino libs tend to hide all the fun stuff effectively diminishing the learning experience. Sometimes it's good to reinvent the wheel (like writing the driver yourself with the sdk) if your goal is to understand how why it works.

I love it! Great roadmap too. In a previous discussion of DIY indoor air quality sensors[1] MQTT+Zigbee was brought up as a good standard interface.

1. https://news.ycombinator.com/item?id=33773786#33775308

Maybe it's a stupid question but for the verification bytes you're adding the different constants, commands and options. For the sleep that comes out to 0x173 (as you also wrote down). Why is the higher verification byte then 0x73 and not 0x173? Or is it a typo?

[Note: I'm not the author]

0x173 doesn't fit in a byte. As the text explains, there are two validation bytes; the first one gets the high 8 bits ("the high byte") of 0x173 (which is 0x01) and the second one gets the low eight bits (0x73).

Ah! Ok got it. Thought it meant some kind of lower and upper "limits". But that makes more sense. Thank you! Just getting into embedded / MC stuff.