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I was thinking about getting a SAF Aranet4 recently but looks like you're tied to their app to viewing the data. This article helped me second guess my choice.

I would much rather such a nice looking device have a simple API that some docker container can query and present a UI for, and/or would integrate with HomeKit or HomeBridge which it looks like it does not.

Does HN have any recommendations? Should I even bother with optimizing another metric beyond "open the windows every couple hours", assuming outdoor AQI is OK?

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These Airgradient blog posts are great marketing because they give people like me a chance to talk about how good their devices are :)

I put together an Airgradient Basic based on their PCB design, a slightly more accurate temp/humidity sensor (in retrospect probably not worth it), and the USB-C version of the microcontroller they recommended at the time. Soldering everything took an hour or so, and I also 3d printer a case. IMO the display doesn't look as nice as an Eink would (a la the Aranet), but it probably wouldn't be too difficult to mod one in.

However I don't actually look at the display much, I have it hooked up into Home Assistant so I can check everything on my phone. Granted, the main lesson I've learned is the one you mentioned: open the windows every once in a while, especially if the oven or stove are on. It was also cool to validate that my air purifier actually works.

That validation does sound very worthwhile. Thanks for the reply and suggestion!

You're not limited to the Aranet4 app. The device speaks Bluetooth and there are Python and Go libraries for parsing the protocol. There is also a Prometheus exporter for it.

Home Assistant already has an integration to read from it as well.

You will need a BT -> HA relay, but you can do that with any ESP32 board and ESPHome.

I'm running hass on a raspberry pi 4 and its built-in bluetooth works fine, no extra setup needed.

Only for huge distances. I have mine connected directly to the BT of the mini pc I use to host HA.

Yeah, I'm running HA on the server that I use for all home services, so I needed the BT relay.

I have no affiliation with Air Gradient (who wrote TFA) but I recently assembled one of their DIY devices (the Pro Pre-soldered version) and I'm quite happy with it.

> Since the AirGradient DIY Pro Kits are fully open-cource [sic] you can send the data to any server, i.e. Home Assistant

If you can put lego together you can assemble this device, and the price is right IMO, especially compared to competitors. I don't think it's as compact or good looking as an Aranet 4, and it's not portable unless you use a battery bank, but's it half the price.

https://www.airgradient.com/kits/

I got an IKEA air quality sensor for $50. It reports readings over Zigbee (PM 2.5 and tVOC, along with temperature and humidity), which is great. The PM2.5 reading is within 2-3 μm/m3 of my laser sensor that I got off of Ali, so quite accurate.

>within 2-3 μm/m3 of

.. had me confused for longer than I like to admit, I assume you meant μg/m3?

Oops, yes, thank you.

My Aranet4 has been great, the original batteries lasted well over a year with even with Bluetooth transmissions enabled, which can be read by any BLE application (I use Home Assistant). You only "need" the app for firmware updates, speaking of which, the most recent firmware update seems to have thrown my calibration out of whack as outdoor air now reads 600ppm. Hopefully they fix it soon.

Achim from AirGradient here.

The open source nature of our air quality monitor kits give you a number of choices for data transfer. You can use the monitor and send the data directly to your end point, e.g. through ESPHome or just change our default firmware and change the http post endpoint to your own server.

Alternatively, if you want to use the AirGradient dashboard, we do also have an API that you can access your own data.

Achim not sure if you'll see this but an idea to really make AirGradient take off in the USA nationally on your https://map.airgradient.com/

You should contact the national public WeatherSTEM program!

They have a great open-data network in all kinds of public community places like universities and firehouses and such.

But WeatherSTEM does not have air quality sensors! That is a huge oversight.

If your hardware can be paired with all their rigs nationally, you'd blow away all other services like purpleair overnight.

https://www.weatherstem.com/dashboard?public_access_token=e7...

Thanks. This looks interesting. I would loved to learn more about it. Could you please contact me? https://www.airgradient.com/support/

I have a Aranet4 linked with home assistant. For quick glances at trends though their app is perfectly fine in my opinion.

i have the aranet4. it can be used with HomeAssistant (https://www.home-assistant.io/integrations/aranet/) and can be tracked using ESPHome bluetooth proxy(https://esphome.io/components/bluetooth_proxy.html) if you don't have bluetooth on your HA machine. using this, i can view CO2, humidity, pressure and temperature in HA.

I have never connected my Aranet4 to anything. I just look at the screen.

ecowitt wh45. you can read data from it with rtlsdr usb dongle and rtl_433 program

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