Public Lab Research note

Raspberry Pi-in-the-sky

by donblair | September 20, 2012 13:54 | 8,215 views | 5 comments | #3908 | 8,215 views | 5 comments | #3908 20 Sep 13:54

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In preparing for the PLOTS LEAFFEST this weekend, Craig Versek of PVOS has just achieved something pretty cool -- a live WiFi webcam feed from a battery-powered Raspberry Pi! As long as this little baby is within range of a WiFi signal, any web-enabled device (laptop, smart phone) will be able to navigate to a web page and see what the on-board camera is seeing. Here's a little schematic of how the device is connected up:


Cost. The Raspberry Pi itself is $35; still waiting for details on the webcam, battery pack, and wireless dongle (the same type of dongle used to get e.g. a laptop online), but they're pretty inexpensive, too.

Weight. The entire device (including the 5 hour battery pack) weighs around 300 grams, and should be light enough to, e.g., include on a balloon or kite imaging payload as a way of making sure that a higher-resolution camera on board is looking at what you're hoping it's looking at.

Testing. Craig is still working out some bugs -- the live video is a bit choppy, and he's thinking he might tweak the setup to simply capture a sequence of still images, instead -- but we're hoping to test the device out on a kite- or balloon-based camera rig this weekend at LEAFFEST.

How he did it: To get the R-Pi transmitting images wirelessly, Craig said he followed the instructions here and here, and provided the following caveat: "Compiling large source packages like ffmpeg on the RPi is not for the impatient - though easy to set up, it took over 6 hours to compile - but is well worth the investment."

Below is a demo video:



I'd love to see an exploded view so I can see what's what. I guess the web cam is underneath?

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Wow, awesome!!! that's fabulous. I'd love to see the code when it's available; it'd be great if it also locally caches the video on the sd card.

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Hi Chris -- yep, the webcam is underneath (can't see it in the static pic I posted) -- it's all sort of a Pi + battery pack + webcam sandwich -- the Pi is unbelievably thin (lighter than an Arduino Uno, I think) ... the configuration is probably a little easier to understand in the video (and I also posted a little exploded schematic above). The webcam in the diagram is the same shape-ish as the one Craig used.

Jeff -- we really ought to post the code asap, yes! After LEAFFEST, we're hoping to post a brief tutorial / code here on PLOTS ... I think caching video / images on the sd card should be pretty straightforward (...? Craig?), as it's really all just Debian Linux, and I'm guessing that someone has already figured out a pretty slick way of storing video from a webcam in Linux. Craig has been pointing out that with the R-Pi, you have all of a standard Linux distribution at your disposal ... we've been trying to wrap our minds around all the possibilities!

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Fantastic work! I'd be happy to help add some other sensors to this project if you are interested. I've created an Arduino clone that plugs in to Raspberry Pi, that our group could probably donate for experimentation.

It can: Easily integrate analog or digital sensors (temperature, air quality, altitude, etc.) interface servos directly so if you have a tilt platform it could be used for that as well.

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What's the nominal output voltage of the battery pack? If you're powering it without some sort of power regulation, I'm rather surprised that it's working as well as it is.

I'm building a battery pack for my Pi out of 8 AA rechargeables in series (~9.6V) regulated down to 5V using one of these:

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