Wednesday, May 31, 2023

Stream Logger

 Last month I thought it would be cool to position AMOS in the stream in our backyard, where it could take still pictures during daylight hours to make a time lapse video of snow melting, leaves budding, and stuff turning green. It would also be a good opportunity to test out the long term resilience of the boat to the elements. I put it in the stream with an anchor, on April 15, so there wasn't much snow left by then. In fact, it melted in just a day or two, so wasn't too impressive as a video. Also, the first few weeks were fairly uniform in terms of foliage coming out (i.e. there wasn't any, spring comes late to New Brunswick!).

Here is a still picture taken by AMOS on May 07:


You can just barely make out that there are tiny red buds on the leaves. At this point, the SD card on AMOS had filled up, taking a picture every 5 minutes for 12 hours per day. I removed the pictures from the card, and set AMOS to just take a picture every hour for the next 3 weeks. I also configured AMOS to go to sleep between pictures, which saved a lot of power and prevented the occasional loss of battery charge when the weather was cloudy for 3 or 4 days in a row. 

The following video was created from just those 3 weeks:


Around May 20, Kelly noticed a mother bear and two cubs playing around in the stream in the vicinity of AMOS. I didn't check on the boat until the 28th, but noticed that it had moved (or been moved?) from the middle of the stream to sitting atop a small dam structure constructed last year by a beaver:



 It's possible that a few days of rain after the 20th floated the boat up onto the dam, but I prefer to think that the bears relocated it. Muddy streaks on the top of the solar panel seem to support that theory. Unfortunately, the AMOS camera was only configured to take a picture at the top of every hour, and no bear pictures got saved. 

Desiccant was placed in both AMOS electronics boxes, but over time, humidity within the boxes did increase, and the front electronics box contained a small quantity of water at the bottom of it when I opened it up on the 28th. The following graphs show the measured humidity levels in both boxes over the entire time that AMOS was out there:



When AMOS was powered continuously during daylight hours for the first 2 weeks, it probably had a beneficial effect on keeping humidity levels in check. 

I have recently ordered some soft iron rods, magnet wire, and small permanent magnets, to try some experiments on a novel type of robot joint. If it works, it will have two degrees of bend freedom, but won't require conventional electronic motors to work, so should be smaller and lighter than most other robotic arm joints. An evening spent searching the idea on the Internet revealed a number of theoretical papers on the subject, but little hard evidence (i.e. YouTube videos of real robots working), so it sounds like a pretty good challenge. :-) 



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