Public Lab Research note


Mobius TrapCam Housing

by tonyc | July 01, 2016 23:22 | 48 views | 7 comments | #13254 | 48 views | 7 comments | #13254 01 Jul 23:22

Read more: stable.publiclab.org/n/13254


Make a low-cost housing for Mobius camera for outdoor deployments.

I wanted to create a low-cost housing using widely available materials to allow for field deployment of a mobius camera, under the widest possible conditions.

Ideally, this would allow for urban as well as natural environments, meaning some level of camoflauge is built in.

Also, allows for connection of external battery via cable port access, should we want to have Li batteries that can be swapped.

My attempt and results

I went with the exterior light fixture I'd mentioned in my previous research note, and a standard exterior, gasketed junction box cover. IMG_4016.JPG

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The key to this was whether or not the Mobius exernal lens ribbon cable would be able to snake through the joint of the head on this thing.

It JUST makes it! Amazing.

The other lucky piece was that the gasket that comes with these things fits excatly onto the glass flashlight lens we purchased for building the first version of these housings. You could make do with no adhesive or caulking, but we but some barge cement on for good measure.

IMG_4021.JPG

For urban camouflage, I thought it would be good to have the shiny, threaded socket in place, as a verification for anyone who looked up there to say, "yup, that's just a bare socket. Nothing to see here..." and not yoink the camera.

The best available method for removing ceramic socket form the metal:

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And then the next happy accident: The mobius CCD module fits friction tight in the metal socket base!

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You can simply shove the ccd unit into the base of the socket, and it holds tightly. Then i simply wrapped the socket in a piece of fuzzy velcro, then friction fit the whole thing into the metal head. Pop in the foam gasket, and you are set!

Questions and next steps

Should the hole on the bottom of the junction box be left wide open? Or should it be closed tightly? Or should we put a simple vapor barrier there?

How waterproof is this as it sits? Would we need to caulk up any of the seams or joints to ensure it's good?

What are some good ways to deploy this outdoors? J-box gives you many options, since it has tabs and holes built in. Simple to wire it up, or just mount the whole thing to a board and mount with rope or ratcheting straps, on a post, etc.

I found one trick of putting a hard drive magnet the box. It is strong enough to hold the thing up, and the Solid state flash memory should survive the magnet just fine.

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How to connect additional batteries? you could just dangle a USB cable out the bottom, and have it attach to an external Li battery, which would have to be made resistant to the elements in another way.

Why I'm interested

Photos are hugely beneficial in building a case. Long term deployment of a simple and affordable camera is something we've been asked to deliver, and I think this may be it...we'll see.


7 Comments

I should note this thing relies on using an extension to allow you to separate the lens module from the camera body. These are widely available for use as dashcam or for drones, etc.

Places like this

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@gretchengehrke

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Haha cool! Reminds me of the "rock camera" from the movie The Cove.

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Here's a bit more detailed image of how the CCD sensor unit is secured by the sheet metal of the socket. Just a happy coincidence the sizes on the "jaw" and the size of the sensor board make for a very snug fit. Then it is easy to mount the socket as a unit into the lamp head part.

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D

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Good stuff, Tony! Can you post information about sizes so people would know which box would have the lucky, snug fit? That's exciting! What else is in the box attached to the cone head of the old light? Could a micro-computer fit in there and control turning the camera on and off? Can the Mobius be controlled by a micro-computer?

Is this a question? Click here to post it to the Questions page.

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No need for a computer. The mobius has a power saving mode that puts it into hibernate between shots as long as interval is greater than 5minutes.

I will write up BOM as soon as I have a stable version of this. Right now the important piece is this one: https://www.thriftcat.org/upc/009326507187/do-it-weatherproof-lampholder-gray

basic, generic lampholder, with the two happy coincidences built in.

the specifics on the lens I used are here: https://www.fasttech.com/p/1088101

I plan on bulk ordering these. They take forever to arrive from China.

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Tony's deployment just came back from the roof, I thought i'd share some details. The weatherproofing appears to have held.

The external battery is drained, but I'm not sure if it re-charged the Mobius. The mobius was set for 5 minute intervals, and ran for . The camera ran for 11 days. Previously Tony had stated the camera could run for approximately 10 days on its internal battery. Given that the external battery is supposed to be 10,000mAh and the internal battery is 820mAh, I'd say that the external battery had a negligible effect.

Images of the deployment:

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