Open Source Outdoor Air Quality Monitor
airgradient.com
airgradient.com
Our outdoor monitor Open Air has been designed from the start as an open hardware project with a beautiful plastic injected enclosure to demonstrate that open source hardware can look and perform on the same level like traditional products.
We do also work intensively with research institutions around the world to test the monitor and ensure that the monitors are as accurate as possible [1].
Happy to answer any question that might come up.
This version we currently only sell as a pre-soldered kit [1] but it is very easy to assemble (no need to solder anything) and you just need to plug a few modules together and close the enclosure with a few screws.
I particularly love the open source nature of them that allows me to redirect their data reporting to my own homebrew data systems.
About to buy some more of them, in fact.
The PRO comes with a nice plastic enclosure, has a larger display and due to its larger size measures temperature and humidity more accurately (since there is more space, the temperature sensor has more distance to active components that heat up).
I run a similar open source app specifically for my little community in Gary, IN https://millerbeach.community and run a RAMP monitor provided by a local company Sensit Technologies, and a PurpleAir II and have about ~4 years worth of data in 15 min intervals. I've been meaning to swap out the PurpleAir with another, but I'll swap it out with this instead!
There are others with 6 in 1 with app control for less.
Aren't there other sensors that would be more useful providing better insights on pollutants and health you could provide at a premium that these cheaper monitors can't.
I'm absolutely miffed by the poor-quality sensors that are off by 10% humidity and 2-3C of temperature. I bought several sensors to try and find the best ones, and now like a man with two watches I'm never sure what the actual time is.
...5 degrees diff. Damnit.
If you write it, people will read it!
I am one of those many people who will read it.
"Sharing is caring"
1. Design
Starting from a set of requirements and what has to go into the enclosure you start working on the design. Here you are often working with other teams that influence the design. These could be other mechanical designers working on interior components, electrical designers working on PCBAs, industrial designers that want to make the exterior aesthetically pleasing and nice to interact with.
The parts is designed with many factors in mind. What material will you be using? How does the part take into account good injection molding design practices (consistent wall thickness, avoiding undercuts, drafts to enable release from the mold, etc.)? How do the parts mechanically fit together? Normally you will be making prototypes at this point (e.g. 3D prints).
Once you are happy with the design you create drawings and send a 3D database and the drawing to vendors for quote.
2. Design For Manufacture (DFM)
Once you get the quotes back and choose a vendor you start the DFM process with your supplier. Their tooling engineers take a look at your design and provide a document with their feedback telling you where your design needs changes in order to be manufacturable. Part of this is running the part through simulations where they simulate how the plastic fills the mold to identify potential issues. You go back and forth until both parties are satisfied with the design before giving approval to start tooling.
3. Samples/Testing
About 6-8 weeks later the vendor has finished the tool and done some tooling trials to dial in their process before sending you the first off tool (T0/FOT) samples. At this point the parts are generally not textured and may have some defects. You inspect the parts and provide feedback about what needs to be improved. At the same time the parts will be tested to see if there are any design issues, if something needs to be changed there you issue the vendor a tool mod report and they quote the costs to make the changes in the tool before sending updated samples for inspection/testing (usually called T1, T2, etc.). Once you are satisfied you have the vendor send the tool for texturing and get samples that are hopefully the final design and appearance.
4. Production
Once the design is done approval is given to start buying the parts in high volumes for production.
How does your approach differ from theirs? Will both interoperate?
A little-known fact about these air quality sensors is that they don't actually measure three different particle sizes, they typically measure the smallest one and then return some statistically determined value for the larger ones.
[1] https://www.digikey.jp/htmldatasheets/production/2903006/0/0...
a) Data quality: You can detect if one sensor fails as the two readings will start to deviate and then replace the faulty one
b) Extend the life of the monitor: The PM sensors with the laser and optics have a limited life. By having two inside, you can alternate the measurement and put them in sleep mode inbetween. Thus extending the life of the monitor.
Instead of 50%/50% time split, can you do something like 40%/60%? This reduces the risk of both sensors failing at once because they have approximately the same duty time.
But how do you know which one is the faulty one?
In the theoretical limit of all mathematically possible failure modes and all possible environmental conditions, this would be impossible of course. But we live in a fairly predictable environment and the nature of the failures is not unlimited. As such, it is pragmatically pretty easy to see the difference.
Air gradient has been extensively discussed here multiple times already.
My own position on this is that there is difference.
If, like today's post, we're talking about what in forum-slang would be a "bump" post, then as far as I'm concerned it has near-zero value. Its basically just attention seeking if we're being honest.
Meanwhile if it's re-posting a link but in the context of a significant change, for example a new version with major new features, then obviously it's a different kettle of fish altogether. That's obviously perfectly fine.
I reposted it because I thought this could be quite interesting for the hn crowd. On the 4th time it got more than 200 comments. Since then I did not repost it again.
Weird, in all seriousness, I never noticed.
The founder reads this.
Founder: What's held me back from buying this is a lack of github links and instructions. EVERY place you say "open source" should link to the repo. The repo should have CLEAR instructions for how to hack this.
There's a lot of copy like "We provide detailed instructions and videos" but NO hyperlink to said detailed instructions or videos. Any place you mention specs should link to ACTUAL specs. What's your BOM? What microcontroller are you using? Do I rewrite the firmware in Python? Rust? MakeCode? Etc.
Those are the tires I want to kick. If my child can program this in MakeCode and it's designed for tinkering, it's a no-brainer. If it's on github, and easy to set up to work from my desktop, it's reasonable. If it involves setting up docker containers and proprietary environments for hacking C code, it's not as obvious a buy. If I can't figure out how to get started in 30 seconds, I assume it's the last one. I have a lot of projects around the house I wish I'd done, and I'm not buying more until a few of those finish.
Also, I will never pay for your service. The whole point of open everything is I control my data.
The other piece I'd like is a dirt-cheap set of temperature / humidity tools. I bought an 8-channel weather station, so I can monitor temperature indoors and in each room. I'd love to switch to something more open.
Again, a lot of this comes down to how easy it is to get started. If I can make dashboards in 5 minutes with numpy / plotly / pylab / etc., I'm delighted. If I can't, but it's not bad, I'm grumpier. etc.
So in conclusion, I'd do user studies and think-aloud protocols with customers.
Build instructions: https://www.airgradient.com/open-airgradient/instructions/di...
BoM, schematics etc: https://www.airgradient.com/open-airgradient/instructions/di...
The supplier answers all your questions on their website (and as you can see, the founder is taking your suggestions)
Also, their software is just as hackable as you seem to want. I was able to create my own dashboard in a very short time using numpy and plotly. I query my archive using duckdb.
There’s nothing new under the sun.
https://www.epa.gov/arp/arp-enhanced-air-quality-monitoring-...
(My city is using QuantAQ sensors, which weren't cheap)
will your data be publicly available in near real-time? as far as I can tell, airnow.gov only has data from airports. will you share this data with the epa somehow?
I currently have TuYa TS0601 Zigbee air quality sensors in every room of my house. I don't think the data is very accurate, but I just use it to automatically turn on the rangehood fan when the PM25 spikes in the kitchen, and an extractor fan in the workshop. Also to monitor CO2 in the bedroom and our offices and turn on the nearby bathroom fans. So I use them more as a boolean sensor and don't really need precise measurements.
I live in New Zealand and fortunately our outdoor air quality is very good all year. If I lived somewhere with frequent wildfires (e.g. Sydney or Melbourne), then I'd probably upgrade to the airgradient indoor sensors.
New Zealand is small and we have a lot of problems (cost of living, housing crisis, low salaries, etc.) so we've been thinking about moving somewhere else, but I don't know if I can give up the clean air. It's actually a pretty nice place to live.
[1] https://www.airgradient.com/open-airgradient/instructions/di...
Doing geophysical air surveys back in the day we'd record distance to ground, temp, humidity, and air pressure in order to have a running estimated mass between craft and ground to correctly scale readings such as radiometric spectrums from ground decay which weaken with mass between source (ground) and detector (craft).
It probably makes sense to put it on a separate WiFi network (or a guest network) if access to the monitor is possible for unauthorized persons.
A huge problem with ZigBee is that it's not OpenSource-friendly. The tools are proprietary and devkits are pretty pricey.
It needs a wired data connection. For crying out loud. Don't screw this up like PurpleAir did.
You already have a micro-usb (or maybe usb-c) plug for the power. You're not adding an extra wire.
The amount of nightmarish grief the wifi in purpleairs causes makes me want to scream.
Even if you manage to magically fix all the reliability problems, it's a safety issue. A town near me whose economy is supported by a paper mill hunted down the person who was running a purpleair and pressured their landlord into cancelling their lease. The town then set up indoor stations at the school and library -- where they report on filtered, air-conditioned air.
You can wardrive for these things using their MAC address. They have to be outdoors.
Stop it.
Wouldn’t data over usb-c require a computer to drive it?
If any of you can recommend a module I would be very interested to hear.
Radon concentration is not a transient state, and you need to measure it for a fairly long time to get a good idea of the true concentration.
It helped me identify patterns, such as CO2 settling in my large living room.
Knowing that the CO2 levels are healthy throughout the day really helps me feel better about living in a new sealed home.
All I need to add is moister meter and CO2 controller to be complete
The simplest format is to send JSON data like the system does anyway, just change the URL it sends to. From there, you can accumulate the data and present it any way you like. I keep my historical data in parquet format on a Pi4. YMMV.