The Groovik’s Cube project has a web site now. It is still a big ambitious engineering project with significant unknowns, but we continue to make progress and the design looks increasingly solid. All we need are more money for parts and more people to help assemble them.
I am working on a project for the silent auction at next week’s fundraiser: a new microcontroller-equipped light-water-pack, running the same dimmer board software used in the Groovik’s Cube. The dimmers have a demo mode which runs until the central computer takes control; the backpack will simply run the demo forever, fading in and out through slowly evolving color cycles, on four independent channels. I like the idea that someone can help support the cube project by bidding on an object built around a piece of its technology.
Do you have any pictures of said water pack in action?
Comment by Aaron Ballman — June 9, 2009 @ 7:15 am
I have a prototype board running the dimmer code, but none of the actual production parts have arrived yet. I had to redesign the power supply this weekend after running some actual power-consumption tests, and battery choice has a big impact on the physical design. I typically hide the batteries and circuitry away in an electronics box, but this time I want to put the microcontroller board front and center, since it contains the dimmer code and thus represents the link to the cube project. Also, it is tiny and sleek and just plain looks cool.
The batteries have been a challenge. The controller runs on 5V, the system draws ~400 milliamps, I want the smallest form factor possible, and I need to either build in a charging system or use a common battery someone can replace in a supermarket at 9 PM on a Saturday night. One bit of new tech per project is enough of a challenge, so scratch the charging circuit. 9V is out – only 500 mAh, barely over an hour. CR2032 are flat and awesome but capacity is even worse – at 3V and 225 mAh I’d need to use at least a dozen. AAAs have about 1200 mAh, three hours at best. AAs are better – 2500-3000 mAh ought to be enough! But each cell only pushes 1.5V, so I’ll need four, which is a pretty chunky battery pack.
I’ve ordered a boost converter chip which claims 600 milliamp at 5V; if that works out I can use a pair of AAs, much easier to fit. Again, though, with the new tech, so I’m not counting on it. I could attach a fully-enclosed 4-cell holder to the bottom of the bottle, maybe with some rubber feet; but square box on cylinder sounds mismatched and clunky. Better idea: enclosed holder again, screw it onto the centerline against the wearer’s back, glue some dense foam onto the cover, and call it a lumbar pad. Then the fact that it doesn’t lay flat against the bottle doesn’t matter. Might be some strain issues, though.
Comment by Mars Saxman — June 9, 2009 @ 8:57 am
Rofl, that’s an awfully long “no.” :-D The reason I ask is: I might be interested in bidding on said water pack!
Comment by Aaron Ballman — June 10, 2009 @ 7:50 am