Comments on: Measuring power consumption – the MacGyver way

By: guijemont

guijemont — Tue, 24 May 2011 18:30:04 +0000

Thanks for the links, will have a look at these projects.

Regarding the jack, I tried that on my camera (not a jack, but a proprietary mini-usb-like camera). Indeed the screen goes black, but the power consumption remains the same as when the screen is on…

For the wind, I had seen that, but the site is quite far from the Zaragoza airport (some 70 km iirc) and in-between hills, so I believe our mileage will vary quite a bit…

By: KickMe

KickMe — Tue, 24 May 2011 18:20:50 +0000

On some cameras plugging a jack into the video output is enough to turn off the screen, saving precious power. If you use arduino you might find useful stuff http://photocerfvolant.free.fr/phpBB2/viewtopic.php?f=6&t=423&st=0&sk=t&sd=a" here or there, in french.

On average wind is 3-4 Beaufort according to http://www.windfinder.com/windstats/windstatistic_zaragoza_aeropuerto.htm . Your mileage may vary. You can design the rig and attach it to either a balloon or a kite depending on the weather.

A kite requires monitoring, especially when there’s ~1kg dangling from its line and people around.

By: guijemont

guijemont — Tue, 17 May 2011 14:11:35 +0000

Regarding CHDK: we think of using it, but I haven’t found a way to make the camera go in “low power” mode, so we might fall back to triggering through the arduino that we’ll have onboard for monitoring anyway (should be doable with the usb host shield over ptp), that way, I think we can rely on the automatic “go in low power mode after 10s of inactivity” mode, which for some reason is disabled with CHDK (even without running a script).
Regarding wind and kite: from what we’ve been told, we can expect a wide range of conditions over the wind, going from “no wind at all for several days” to “sand storm”. To be versatile, we are thinking of making a balloon-kite hybrid. One thing to consider is that we would like to be able to have the camera up for a long time while being able to forget about it and enjoy the event. I’m afraid a kite-only solution would require permanent monitoring.

By: KickMe

KickMe — Tue, 17 May 2011 13:33:51 +0000

Or, you know, put fresh batteries, load up CHDK (you did look into CHDK, right?), fire an intervalometer script and let it take pics till death ensues. That seems simpler and more accurate. Did you check if the festival location is usually windy ? If it is, a kite would be better suited than a balloon. Good luck!