Recently I came across Sensor community, a contributor driven global sensor network that creates Open Environmental Data.
Why I just discovered the project recently is beyond me, but it probably had to do with my interest in the maker community in general and searching for a useful project to take part in.
Although not being a maker myself, heavily interested nevertheless, I ordered and built the sensor from several necessary parts, that all could be ordered locally.
It was quite fun to solder some minor parts and being able to easily flash the firmware on the board, all using a simple but readily available manual. Although not everything was quite up-to-date and exactly one on one applicable, I could still figure out how to connect the different parts. This made it all even more engaging and exiting to be able to boot up a working particle sensor. 🎉
Projects like these should deserve more attention, even better, more contributors.