The first outdoor sensor

A project log for Particulate Matter Sensor Network

Gathering more data on PM in our environment

tiefpunkttiefpunkt 11/20/2016 at 17:440 Comments

Our maker space had a booth at a local street faire, so we decided to show off our project there as well. Since the aim is to place sensors outside, and we only had some indoor sensing units so far, it was time to build an outdoor version.

The case is built using plant coasters. We lasercut a big hole in the middle, and some small mounting holes on the rim of each coaster, and assembled them using some threaded rods. There's an acrylic strip on the inside, onto which the sensors and the electronics are mounted. The whole thing is connected to an aluminium tube, which is used as a stand, and through which a cable for power runs.

We used one of those WeMos mini ESP boards, and connected the sensors using standard connectors, so we could later reuse them once we got proper PCBs. Some testing showed that we were having some power issues, probably because the cable was too long. We were able to address them for now with a big capacitor, that we pretty much just jammed into one of the connectors. Good enough for now, and we actually got quite a few people interested in our project at the fair.