Making and Breaking

Things are finally starting to warm up around here. If we can get a few days in a row of warm temperatures, I think I'll be able to take AMOS across the road to the stream and beaver pond for a field test. First though I'll need to finish some repairs for a couple of minor mishaps that took place recently.

Thankfully I was able to sort out the remaining Bluetooth Low Energy issues for the Android version of the Boat Captain software. It now can send and receive data and download images from AMOS. I needed to lower the quality of the jpeg pictures though to allow them to download in a semi-reasonable length of time. Next up will be the iOS version. In testing things out though, I happened to notice that the stem of the camera housing had snapped off, near where it entered the front electronics enclosure. The stem was a 3-D printed part, and the interior of it was only partially solid, with a sort of honey-comb-like structure for half of its wall thickness. I suspect this camera housing was not quite water-proof anyway, so this became a good opportunity to re-design it into something smaller, lighter, and more water-proof.

Here is the result after a few 3-D print attempts:

It was a bit smaller than the old one, and the screw holes for the Plexiglas window worked better with this design, so that the window had a nice amount of compression on the o-ring underneath. But the overall design was still not waterproof. Once I had it actually mounted into the hole on the electronics box, it became totally obvious that water would just leak down through the gap between the lower ring and the vertical tube and then run down the tube onto the electronics below. This prompted an idea to close the gap by melting some extra PLA filament with a heat gun into the crack, effectively creating a permanent bond between the lower ring and the vertical tube (both also made of PLA). This actually seemed to work pretty well, but unfortunately, the heat gun also melted the nice circular hole of the electronics box, so that it became much larger, and now looks like this:

So this required ordering a new box (~ $30) from Amazon. It will probably require a few hours to drill new holes into it, de-solder wires, install new cable glands and then re-solder wires. Argh.