Taking time-lapse video of a construction project?

January 8, 2007 11:32 AM

How can I make a self-contained device to take a time lapse video of a construction project? Better still, how can I turn said device into a webcam?

If all goes well, construction will begin on the house in a couple of months.

I'd love to get it on video. I'm a geek. I love to do things for no other reason than because I can. I love to build stuff.

Primary goal: Upon completion of the project, to have a time-lapse video of the entire thing. Say, take one frame at noon every day.

Secondary goal: To have a webcam on the site that I could view whenever I wanted.

I have some spare hardware I could use, including an old Dell Laptop with Win 98 and Ubuntu on it. I have a Logitec camera that will plug into the laptop, I even have an old Olympus digital camera. I could throw a few bucks towards the project though I'd like to keep the costs down.

I envision some sort of weatherproof container holding the laptop, battery, and camera. The project will take nine months to a year so the device will have to work through all types of New England weather.

Once I get the hardware down I'm sure there's enough OSS out there to do the rest. Ideally if the thing rebooted it would start right up again.

The main problem with achieving goal #1 is the lack of power at the site. Not only will there be no electricity at the site during the early phases of construction, but the camera would be located on a tree or shed at the rear of my back yard, too far to run an extension cord even if there was power at the house. What sort of battery pack would I need to keep this running? I'd be close enough to visit the site once a week or so but I wouldn't want to have to change batteries more often than that. I have one of these but they're only good for 40 hours at most.

I've thought of solar but there are too many trees in the area, I don't think it would be reliable. There might be an hour at most on a good day when a panel got some sun, but that's about it. Also, that would probably cost way too much.

Keep in mind I don't want to involve the contractor in any way. I figure they have enough to deal with I don't want them having to worry about the owner's silly pet projects. I'd tell them about it just so they knew I wasn't trying to spy on them.

I know my neighbors but I'd feel weird asking them if I could run an extension cord from their house for nine+ months. I'm hoping to avoid that.

To turn it into a webcam I'd need the first goal met, plus a net connection. I don't see any way around this beyond asking the neighbors if I can hook up a WAP somewhere. Is there a way to rig up some sort of cell phone modem that called up a dial-up ISP once a day?

I know it seems like I've answered a lot of my own questions but I'm hoping someone out there knows about some device that I haven't yet thought of. How do people build those www.watchabearshitinthewoods.com cams?

posted by bondcliff to computers & internet (7 comments total)

Do you plan to visit the site daily?

If so, you could stick a monopod into the ground and take a single photo with your digicam from it every day.
posted by b1tr0t at 11:39 AM on January 8, 2007

wildlife camera
posted by b1tr0t at 11:47 AM on January 8, 2007

For the container, I've seen some scientific projects put together in Pelican cases; they are water/weatherproof and made of a plastic that's soft enough that you could drill through to run wires, if you needed to. You'd just want to seal the wire outlet well, since it would obviously compromise the integrity of the case. My biggest concern would be overheating of the battery and laptop in the sealed plastic case.

The cheap alternative would be military surplus ammunition boxes; they are generally gasketed and waterproof. The ones used for mortar rounds are typically large and flat. You used to see them in a lot of surplus catalogs, but I'm not sure how easy they are to come by now that the glut of Cold War surplus stuff has mostly passed. Metal would have the advantage of keeping the stuff inside from overheating, if you did your heatsinking right. (Of course, downside is you'd have to worry about rust, but that's a tractable problem.)

For the camera, it depends a lot on how much money you want to spend. I'm not sure that attempting to weatherproof a camera that's not designed for outdoor operation is going to bring you anything but pain. If the hardware is regarded as disposable, I suppose you could try making something out of plexiglass, but every time I've seen someone try to do stuff like that, it's ended with moisture getting trapped inside and condensation and fog.

There are network cameras that are designed for this purpose and are weatherproofed, and would also be easy to interface with the computer, and run off of low-voltage DC (typically 12V, so you could use gel-cells), but you're talking $540 for one. But with one of those the computer side can be very simple.

Alternately you can get just a camera in a weatherproof enclosure, which would only run you a little over $100, but the output wouldn't be digital and thus you'd need to figure out a way to digitize the video so the computer could save it. Getting video encoding hardware to play nice with Linux can be trying under the best of circumstances, so I think you're a sucker for punishment if you go that route.

You mentioned a shed on the property. If you have a shed, and don't need the entire thing to be sealed up and self-contained in weathertight cases, things get much easier in terms of power. I'd get a bunch of big RV/Marine batteries and use them for power, with a DC/DC converter to produce the right voltage for the laptop, but you'd need to swap them out for charged ones every few days. I don't think there's any cheap method of charging the batteries off the grid. Solar panels, etc., are not going to give you enough juice unless you're talking about laying out major cash.
posted by Kadin2048 at 12:20 PM on January 8, 2007

Batteries are rated in Amp-Hours. You need to determine your load (measure the amp draw of all your equipment) and then determine how much battery you need to to support that load.

So for example if your laptop and web cam pull 1 Amp at 120V then you'll need 10A at 12V. Commonly available good size deep cycle batteries are somewhere in the 100-250 AmpHour range so would run your load 10-25 hours. Keep in mind that unless your laptop happens to have a 12 volt power supply you'll need to run an invertor which at best will be 80% efficient. And it takes hours to restore tghe batteries back to full capacity so you'd need two sets.

Unless I could obtain power from a neighbour I'd skip the computer. Instead I'd set up timer (say a vacation light timer or electric clock or even a 7 day wind up clock) to activate the camera. The timer would run for a long time off your battery pack and even longer off of a couple golf cart batteries and an invertor. This would be easy to do with a 35mm manual camera with a motor drive (say a Pentax ME Super) as you could activate the camera mechanically with a cam. And the ME Super features an auto exposure mode. 35mm equipment like this is really cheap on the used market, resale values have been killed by digital.

It's a bit harder to do this with consumer digitals because they insist on shutting themselves off but it would be buck simple with my D70s. If you can set the camera to not shut off you'll be ahead, though you'll need to wire up a big battery (say a deep cycle automotive or golf cart battery). If you can't force the camera to stay on you'll need to rig something up to first turn the camera on then activate the shutter. The guys taking digital pictures with kites might have some ideas on how to do this.
posted by Mitheral at 12:24 PM on January 8, 2007 [1 favorite has favorites]

I'd get a bunch of big RV/Marine batteries and use them for power, with a DC/DC converter to produce the right voltage for the laptop, but you'd need to swap them out for charged ones every few days.

I dont understand. From what I read of the question, the whole setup only needs to wake up once a day, at noon, and snap a picture. The laptop could be setup to sleep, wake-up at the right time and snap the pic. Why would the battery requirements for this be so big?
posted by vacapinta at 12:25 PM on January 8, 2007

Secondary goal: To have a webcam on the site that I could view whenever I wanted.
posted by noloveforned at 12:45 PM on January 8, 2007

Hop over to Pigeon Point Project and shoot a note to Nick about his renovation projectcam. He may have some ideas based upon his experience.
posted by jeanmari at 1:48 PM on January 8, 2007