Hey Community! I’m a long-time lurker and HA user. As winter season approaches quickly again, I have once again started looking into a CO2 Sensor that fulfills all my (nerdy) needs. Something simple, reliable, non-cloud, can generate statistics and can also output some form of status. Also many projects just come with some kind of cheap sensor that tries to estimate the CO2 value from other measurements… not really what I want
Now hear me out on the display topic. I decided that I wanted something that is simple and does not include any traditional e-ink display, but rather a traffic light style with individual RGB LEDs. This is enough to display the current status and can also allow individual LEDs to be used for secondary information, but it doesn’t cost a fortune and is a much more “minimal” approach.
Now, couldn’t you just easily put all of that on a breadboard? Yes, you could! But wouldn’t it be much nicer if there was a device that you can simply flash through it’s USB type-c port?
For the sensors, I chose an SCD41 (high accuracy even for higher CO2 values) and a BME280, which allows us to provide pressure compensation data to the SCD41 locally. Additionally, I added an illuminance sensor that you could use to control the brightness of the 8 SK6812 LEDs. There is also a small buzzer that I personally won’t use but could become handy for some kind of CO2 “alarm” or just playing subtle notifications.
Now, please provide your thoughts including your views on sensors, LEDs vs. display, power etc! I currently run a prototype with the v1 prototype being ready shortly. Please note the “for ESPHome” is still pending!
Some sort of edit: I already sell electronics within the EU and now about the regulatory requirements. EMC testing will be performed and I plan to sell the PCB fully assembled as “product”.
I was just searching for a simple CO2 + humidity sensor.
I need that to integrate into HA so that I can use the data to display on the esphome modded wall displays (nspanels with esphome) I use in every room (and sell, btw ). Currently I’m using aquara humidity and temp sensors but co2 sensing is a desired feature and I couldn’t find a simple solution, yet.
My partner and I were waking up tired with headaches fairly often, and putting it down to sinus congestion and (i believe) undiagnosed sleep apnoea. I while back I happened across an article about CO2 levels and have since got into the habit of leaving the bedroom door open, as well as trying to open windows more (easy as we come into summer).
It seems to have helped - but I would also like to get a couple of CO2 monitors if not too expensive.
I agree that a traffic light indicator would be appropriate on the box - as long as a more accurate figure is supplied to Home Assistant. Come to think of it, maybe skip the green when within normal range to save battery life and make the warning colours stand out more ?
Can you give an indication of what ballpark the price is likely to be ? I do realise there are lots of factors to be taken into account.
Thanks for your feedback! That’s exactly what I built this one for. I don’t want another display (already have enough) and rather needed something to really know when to open a window. Skipping the green is super easy - with ESPhome you can just remove the line of config. I will most likely provide a config where you can just control the light from home assistant entirely.
Ballpark will most likely be ~100 € after all. I can only produce small series right now, as my brand isn’t really established for any smart home (yet) So this will be some sort of experiment.
Sounds like the sort of product that kickstarter.com (and other crowdfunder) is designed for … though you may also benefit from wider publicity, mentioning your product in more maker forums.
For me 100 Euros sounds a bit expensive - but I have noticed that the CO2 detection chips are quite expensive by themselves,
). Currently I’m using aquara humidity and temp sensors but co2 sensing is a desired feature and I couldn’t find a simple solution, yet.