Cheap CO2 Sensor?

Anyone know of any cheap CO2 sensors that are compatible with HE?
Looking to control a solenoid for my CO2 tank. Thanks!

There are probably others, but the only one I know of is this one from ecowitt. And while it isn't cheap, the ecowitt gateway, which costs about $30, does work locally with Hubitat.

Ecowitt sensors, gateway and the Hubitat integration are all very reliable.

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Just found this one which is much cheaper:

@kkossev -do you have a driver for this sensor?

I read that these are not that great when it comes to accuracy. Have they since improved?

I have no idea. But I can vouch for the ecowitt sensor being very accurate and responsive. It also does active sampling - especially useful for PM2.5.

I just thrown one right into trash.
You will get what you paid for.

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You can also do AIRgradient DIY presoldered kit. CO2 is one of the sensors it has. It can also add others sensors you can add ifnyou want to.

I wrote abpost on how to directly integrate it. I have one running on my dev hub right now.

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I can confirm that these cheap Tuya air quality sensors are absolute garbage, don't buy them!

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Looking at that - looks cool but it's not "cheap" and involves some tinkering for which I lack time. I was hoping for something in the $20-30 range but that might be wishful thinking. I've seen CO2 sensors going up because people are using them now to monitor indoor venues due to the pandemic.

I did come across a couple people hacking the Vindriktning Air Quality Sensor from Ikea. One guy attached a iAQ Core CO2 sensor and wifi module to it. But again, it suddenly becomes a cool, yet pricier sensor one has to have time to tinker with:

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The reason I mentioned the Air Gradient DIY Pre-Soldered kit is that most if not all of the tinkering is done for you. The main PCB is all pre-soldered and all of the standard sensors are included have the pins headers soldered on. You can literally have that sensor up and running in less than 5 min. All you have to do when it arrives is push the pin headers for the sensors into the board, Screw it all together and power it up with USB-C. When it boots up it will give you a Hotspot to connect to complete the setup and attach to your wifi. After that it just runs and reports to Air Gradients servers. If you then want that kit to attach to HE you have a few additional i outlined [here](Air Gradient integration with Maker API. Those steps are pretty straight forward but do require a little bit of setup.

The nice thing about the AirGradient DIY sensors is that if you don't mind a little bit of soldering you can get just the sensors you want and attach them. The two most expensive sensors in the device are the PM2.5 sensor and the S8 CO2 sensor. Even on aliexpress those two can be fairly pricy. The Air Gradient kits also come in a variety of setup based on if you mind doing a bit of soldering. You can get the basic version for $1+shipping if you want and then just get the S8 sensor and a microcontroller.

If your hope is to stay under 30 that will likely be quite difficult.

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I read quite a bit after you posted it originally and it seems like a great device and a reasonable price point. Problem is, my wife is curbing what gadgets I buy.

When you start getting up into this pre-soldered $100 range I'm back at "should I just buy another Velux with Netatmo Sensor" which I already have (granted, having some difficulties connecting them to HE atm.)

I might at some point revisit this device.

I was hoping someone would have a much simpler and less costly solution just to control a level.
For greenhouses, they also sell switches with built-in CO2 meters in them which are also in this price range.

If all you need is CO2 you could do this by getting the DIY QA Kit. Then the Sensair S8 Sensor and Lolin Wemo D1 Mini.

  1. DIY AQ Kit $24
  2. SenSair S8 from AliExpress $15-35$
  3. Lolin Wemos D1 Mini from Ali Express. 3.70

The best part about this is that if you decide you want more sensors you can just purchase them and add them at any time.

I think the Sensair S8 is getting it's price raised because of parts shortages.

If this is for a green house you could even get this sensor to easily add Temp and Humidity monitoring for just a few bucks. This would also need the cable to connect the Temp/Humidity sensor for 50 cents.

That can keep the price down a bit but would require you to solder the headers on the Wemos D1 Mini. Since this is all of the same stuff that is part of the pre-soldered kit you can use the same sketch and it would just work and not report the values for the missing sensors.

Unfortunately the most expensive part other the then AQ DIY kit is the CO2 Sensor. with the best pricefor the Sensiar S8 sensor this is all about 45.50 + Shipping so probably still close to 65-70 bucks. Not sure if that gets closer to your price range. but if you are soldering for the IKEA option not sure why this wouldn't work well for you.

any other idea about CO2 or/abd PM2.5 sensor z-wave/zigbee?

CO2 and PM2.5. But I don't know if there's a Hubitat driver.

https://store.zwavecenter.com/index.php?route=product/product&product_id=338

this i know but is not cheap if you need more than 5 pcs.

Download the Hubitat app