We are developing an open-source outdoor monitor

I am happy to let you know that we have started developing an open-source, open-hardware outdoor air quality monitor. On the development of this unit, we are working closely together with universities as well as NGO’s in order to design a highly accurate product that also works well as a citizen-science monitor.

Here are the first pictures of the functional design:

As you can see, the sensor compartments will allow flexible configurations of either redundant sensors or different sensor modules in the future.

Above is a purely functional design and we currently work with visual designers to get the outside look right.

At the moment we are running a survey to better understand the hardware features and air parameters that people are interested in. If you have 5min time, please fill in our survey:

I also would like to invite a discussion here.

So if you have any questions or comment please post it here!

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This is great. I am highly interested in putting this outside my house.

What will be the approximate size of this unit? It looks like you plan to use the same PM modules as in the indoor DIY kit, is that correct. Are these modules good for outside use?

Footprint will probably be around 18 x 8 x 8 cm.

The redundant slots will allow for a very accurate PM measurement and also extended lifetime of the PM modules (as they can be put into sleep). It also allows to detect drifts in one PM module easier.

Yes, we plan to use the same PMS5003 modules which are suitable for outdoor.

This is great and I will be buying one or two.

My big issue / desire is around power - please can we integrate the ability for power to be supplied by genuine 802.11af / at POE, LIPO and or solar?

As another thought, and it is moving somewhat away from air quality, but could a rain bucket be integrated into the design, or at least an option to connect a rain bucket and wind vane / speed such that we could build a complete weather station on the same ESP32.


Jon, great suggestions.

The enclosure will most likely have mounts on the outside where you could add additional items e.g. for rain, wind, solar etc. We will also ensure we have enough empty space inside to accomodate batteries and additional electronics.

Since it will be a completely open design it should be easy for people to integrate add-ons.

Having said that, each component that is added increases complexity, so we will probably come out first with a relatively simple version but maybe an eco-system around the sensor will evolve with additional integrations for different purposes.

The MCU’s we currently use support 802. 11 b/g/n.

I would be strong tempted by such a beast.

For me, powering an outdoor sensor is the biggest issue. I have trouble running cables safely from indoors to outdoors and don’t want to use an exterior power outlet on a long term basis. Thus, powering this device with a solar panel is likely the only reasonable option.

Almost every other feature (other than basic functionality and ability to retarget the data collection to my own system) is secondary.

This sounds amazing.

The survey asked about PoE support… I would be very in favor of standard PoE. As the necessary components drive up cost/heat/bulk, could they be optional? Like on the Raspberry Pi?

Most of the items in the survey will probably be optional but we need to plan for these options and they might impact the design of the enclosure and layout of the pcb.

The other thing that I would request is that only standard screws are used to hold the enclosure and internal components together…
The only problem I have with the ‘indoor’ pro unit is those pesky M6 Torx. I find that certain cross-head phillips drivers will turn some of them, but not all. Dam annoying when you have to order a new screw-driver to put the unit together!


The torx screws are actually a lot better -especially if you need to open the enclosure a few times so we are planning to fully move to torx and include a torx screwdriver in the kits.

Dont get me wrong, as a professional Engineer, Im a big fan of Torx. I just think all DIY items should be able to be put together with tools that most would have, and if not, provide the tool in the kit.

One of the things I love about the ‘indoor’ pro kit is the attention to detail and thought that has gone into it. Looks like the outdoor version will be the same:)


Yes we will provide a torx screwdriver in the kits.

Did my duty. Answered the survey.
I left a comment regarding solar power. In my experience if solar power is to be incorporated, the panel should be decoupled from the main device. This is because you need to have the solar panel exposed to direct sunlight while the weather station would need to be shadowed for accurate readings.

I’d actually like the integrated option personally, as the panel would help shield the device from the sun