prototype two - how should I proceed?

[morrowwm]

Thank you for the very nice, polished, exciting software. I would make more progress if I didn't spend so much time on the map, looking at everyone else's beautiful images and videos.

I'm on my second prototype. It's an RPi3 with Arducam 16MP Autofocus camera, in a used peanut butter jar. The camera is looking through a hole in the jar with an SLR skylight filter hot glued on it. I'm waiting for an acrylic dome to arrive.

This should be very waterproof, but:
Question 1: How big a concern is overheating in the summer? Do I need active cooling with an RPi3?

I have it sitting on our deck, pointed roughly at Polaris. The camera lens doesn't have a very big field of view. Our yard is heavily treed, so a full 180° fisheye lens is only going to image trees around the perimeter. I could put it on the roof, to at least get above some of the trees.

Question 2: Any innovative solutions to see more sky?

• special mounting?
• black out constant light sources by painting part of the lens cover?
• point at north, or straight up to the zenith
• what focal length / FOV lens makes sense?

I also have an RPi4 outside, listening to ambient sound and detecting bird calls using BirdNET. The RPi4 is reasonably busy, running a TensorFlow ML model to identify bird songs. But only in bursts. It has a PHP-based web site which by default assumes it's the only web software.

Question 3: How well does allsky cooperate with other web software? Could I run allsky and BirdNET-Pi on the same Rpi4?

[EricClaeys]

@morrowwm,

1. Is the Pi in the peanut butter jar? If so, then unless you live where the summer isn't very warm you'll probably want to consider some type of cooling - at a minimum filtered holes in the case to let air circulate. And paint it white or silver. A lot of people, myself included, have a fan that sucks in air, blows it over the Pi and into the dome (to reduce dew), then out some holes. As far as I know the RPi cameras don't get very hot but the Pi will, and when it does it throttles its speed.
2. mounting: Mount above as many trees as possible, but keep in mind you'll occasionally need to take the unit down.
   paint: some people have painted parts of their dome to block neighbor's lights, etc. I assume it works since I never heard anyone say anything bad about it. Keep in mind that black paint will fade if it's in the Sun so you'll need to repaint every couple (?) years. Not a big deal though. I suggest using black tape initially to make sure you don't cover too much. Tape will be easier to remove than paint.
   direction: Most people point straight up with North either at the top or bottom of the picture. If pointing somewhere else works better with your trees, go for it.
   lens: This depends on your sensor size, how much sky you can see (the more sky, the wide FOV you probably want), and whether or not you mind seeing a circular picture, a picture with just the top and bottom cut off, or a full rectangle. See the documentation page on picking a lens for more info.
3. Allsky uses lighttpd for the web server and won't work with any other webserver. You could probably run two web servers but you'd have to change the other server to use a different port, then use that port number in all URLs.

[morrowwm]

Thanks for the suggestions, Eric.

1. I'm in Atlantic Canada, so only really hot for a few weeks in the summer. Yes, Pi is in the jar. I'm considering switching to my RPi4, which will need cooling.
2. All good information, thank you!
3. Ah, I the Birdnet system uses caddy (https://caddyserver.com/), which I believe I can have listen on a different port. caddy is weird though. Might be too much hassle trying to integrate it all.

P.S. Got a good image or two of a moonbow, and some decent time lapse last night. So much fun.

[morrowwm]

Update: I switched to RPi 4, still using the peanut butter jar concept for enclosure. The Pi does throttle itself on sunny days. With warmer weather coming, it was getting to be too much. I was worried about drastically lowering the lifetime of all the components. So I hacked a small laptop fan onto the case.

Youtube short

I'm not sold on this case concept, so I haven't painted it to keep heat out, or added bug shields to the new forced cooling holes. I'm now thinking of moving the camera into a smaller enclosure, and keeping the Pi indoors, up in the attic. Connect the two with a long flex cable. This will improve the viewing area (above trees), weather proofing and make cooling a lot easier. Before I made today's modification, it ran without problems for 28 days.

[EricClaeys]

I enjoy seeing how creative people are with their cases and cameras. Especially when people use spare parts.

I think there's a limit on the camera-to-Pi flat cable length, like 1 meter?

If you get a PoE (Power over Ethernet) HAT you can run a single Ethernet cable to the Pi so won't need the (I assume) power supply in the enclosure. That should also reduce the heat.

[morrowwm]

I think there's a limit on the camera-to-Pi flat cable length, like 1 meter?

Right, I have a 1 meter flex cable. It's working OK on my desk. Will be interesting to see once it's higher up in free air. Especially during lightning storms. I'm a bit worried about how good an antenna it might be. Should go inside a metal conduit? Or stick aluminum tape on it to act as a shield?

[EricClaeys]

@morrowwm, Good question about lighting. I have no idea. May I suggest asking on the Allsky Facebook page? A lot more people are there.
My observatory camera is at the top of an 18' metal pole which is in a concrete base that has a grounding wire. That pole probably acts as an antenna more than the shielded Cat 6 cable that's in a PVC pipe.

I ordered an Ethernet extender for my RPi HQ camera. It uses a Cat 6 cable to overcome the 1 meter limit of the flat cable. @Alex-developer has one.