Wapsi Square Forum

Okay, so the Raspberry PI computer costs $35, and, except for keyboard and display (a TV will do) is a fully-functional Linux computer.



Well, here, courtesy of InfoWorld are a few - more (some of them Rather Silly) are in the article.

Supercomputer



World's Smallest Arcade-style game console (runs MAME, so it could, in theory, run almost any arcade game)



DSLR with embedded computer



20-inch boat that will cross the Atlantic, taking scientific measurements.



High-altitude sounding balloon

I see your mame arcade and raise a space invader
http://nootropicdesign.com/hackvision/

Not a rasberry pi but an arduino micro controller which is even cheaper (2$$) and smaller

I'm partial to that one


the flame thrower jack o lantern is not bad either
http://www.instructables.com/id/Flameth ... O-Lantern/

The Raspberry Pi is an actual, complete computer. And MAME lets you play Space Invaders. Or Donkey Kong. Or Street Fighter. Or Millipede. Or Spy Hunter. Or Xevious. Or Crazy Climber. Or Bank Panic. Or pretty much any game that's ever been out in arcades.

Precisely AS they were in the arcades.

Find a (legal, of course) place to download the ROM image, and ...

I must admit to some skepticism about the cross-ocean boat.

Not that I doubt the Pi's ability to act as a control module and manager... it looks as if it should have plenty of cyberpower to handle a job like that... run a GPS, maintain a map, etc.

But... a "130 watt solar panel" on a boat less than 2' long and perhaps 6-8" wide? This strikes me as unbelievably optimistic. Seems to me that a panel of that size would have to be sitting at the focal point of a rather large concentrator to develop 130 watts of output power. Peak solar energy delivery seems to be on the order of 1 kilowatt per square meter, panel efficiencies of above 20% are rather hard to come by, and there's no way that they'll be able to put a sun-tracker on a small model boat like this.

If they average 10 watts during the day, out on the Atlantic, I'd be surprised. That's plenty to run the Pi and drive a small motor and maintain some forward motion, but they probably won't be getting up near hydroplaning speed

Or, am I completely whacked out in my calculations? Or maybe they're planning on towing a solar raft behind the boat?

Dave wrote:I must admit to some skepticism about the cross-ocean boat.

Not that I doubt the Pi's ability to act as a control module and manager... it looks as if it should have plenty of cyberpower to handle a job like that... run a GPS, maintain a map, etc.

But... a "130 watt solar panel" on a boat less than 2' long and perhaps 6-8" wide? This strikes me as unbelievably optimistic. Seems to me that a panel of that size would have to be sitting at the focal point of a rather large concentrator to develop 130 watts of output power. Peak solar energy delivery seems to be on the order of 1 kilowatt per square meter, panel efficiencies of above 20% are rather hard to come by, and there's no way that they'll be able to put a sun-tracker on a small model boat like this.

If they average 10 watts during the day, out on the Atlantic, I'd be surprised. That's plenty to run the Pi and drive a small motor and maintain some forward motion, but they probably won't be getting up near hydroplaning speed

Or, am I completely whacked out in my calculations? Or maybe they're planning on towing a solar raft behind the boat?

Well model A without a display can get by with 300 mA at 5V, with a load ratio quite low. So while 10W for a full day may not be enough it is in that ballpark imho.
Model B needs 700 mA

However, in a marine environement, the rather shaky connector for the SD card may not cut it

Dave wrote:I must admit to some skepticism about the cross-ocean boat.

Not that I doubt the Pi's ability to act as a control module and manager... it looks as if it should have plenty of cyberpower to handle a job like that... run a GPS, maintain a map, etc.

But... a "130 watt solar panel" on a boat less than 2' long and perhaps 6-8" wide? This strikes me as unbelievably optimistic. Seems to me that a panel of that size would have to be sitting at the focal point of a rather large concentrator to develop 130 watts of output power.

Looking up panels online, all of the 130-watt panels i can find are a tad less that 30" x 60".

OTOH, it looks as if the report was a little garbled - the 20" boat seems to the the Proof Of Concept Vehicle (POCV); i can't find any info on the final version's size, but i'd bet a minimum of six feet long, possibly even larger if they're using that panel. A photo of the POCV hull (a commercial model kit hull) before paint and/or assembly (note measure below the hull):

Fairportfan wrote:World's Smallest Arcade-style game console (runs MAME, so it could, in theory, run almost any arcade game)

NEAT!!

Neat. How many of them to control my amateur rocket into LEO? Or, heck I've always wanted my own lunar probe mission.

NOTDilbert wrote:Neat. How many of them to control my amateur rocket into LEO? Or, heck I've always wanted my own lunar probe mission.

Well, at 512 MB RAM and a processor some ten times more powerful than early Pentium models, it sure beats the pants off of anything we had back in the 80's, much less anything they had back in 1969...

So in theory... it's quite possible. Depending on how you do it, I could see a single one of these being able to run your LEO Rocket, with enough groundside support.

After all, it's going to HAVE to be private industry or citizens who will get us into space, considering the government has all but abandoned the project. I about punched my monitor when Obama shut down Apollo project, then had the brass balls to state, when asked what NASA will do, 'monitor global warming'.

Heck, I could see independent engineers releasing economical rocket blueprints under the GNU to go with the motherboard and chipset. Mind you, fabrication would still be exceedingly expensive, but every little bit helps.

Well, the electronics were never the real problem; fabricating the spaceframe, fitting the transat motor and trying to scale up the reactionless thrusters have been problems 2, 3, and 4.

Problem one? Budget, of course.

NOTDilbert wrote:Well, the electronics were never the real problem; fabricating the spaceframe, fitting the transat motor and trying to scale up the reactionless thrusters have been problems 2, 3, and 4.

Problem one? Budget, of course.

Fabrication can be outsourced to aerospace manufacturing companies. That might also take care of the transat motor, depending on what kind of parts they keep in stock. Scaling up the reactionless thrusters... is a more difficult problem.

Of course, that will likely trade off Problems 2 and 3 for an even bigger problem 1, but hey... thems the breaks, right?

Actually... now that I think about it, the less mass a rocket has, the easier it is to get it higher. This computer has extremely low mass, and more importantly, is physically quite small. It would be easier to get a 2 foot tall rocket into orbit than a 2 meter tall rocket, assuming you can shoehorn in fuel. And that's plenty big enough for a camera taking pictures from LEO

What kind of reactionless thruster are you planning on using? This might not be so impossible after all... I mean, fiberglass molding isn't *that* expensive, although it weighs more than, say, carbon fiber (which would be expensive)...

A few years ago on Quantum Cavorite (a science article website, now defunct) there was a paper published about a Mach's Principle propellantless propulsion (Similar papers can be found thru Wiki). Basically the desktop prototype consisted of two capacitors and a piezo-electric vibrating crystal. A sine wave current was fed into the two caps 180 degrees out of phase; this was synced to the frequency the crystal vibrated, 90 degrees out of phase.

The upshot: when the caps were moving thataway, they were full of electrons - moving thisaway, they were empty of electrons.

That's all - electricity in, mass change during oscillation equals movement.

And according to the math - the thrust increases by the forth power of the frequency. Double the frequency, SIXTEEN TIMES more thrust.

Yes, this needs to be scaled up. it would open the solar system to us.

I've heard of that, but I didn't investigate further because it sounded like a hoax.

I think it has to do with the difference in mass of an electron traveling relativistically and one (nearly) at rest. In the wire, it has low mass, traveling near SOL. In the capacitors, even vibrating at several thousand htz, electrons are practically at rest, and heavier. It's kind of a 'cheat' around the closed-loop dynamics.

Or not. Math more complex than quadratics gives me migraines.

Sounds like an electronic version of the Dean Device to me.

NOTDilbert wrote:I think it has to do with the difference in mass of an electron traveling relativistically and one (nearly) at rest. In the wire, it has low mass, traveling near SOL. In the capacitors, even vibrating at several thousand htz, electrons are practically at rest, and heavier. It's kind of a 'cheat' around the closed-loop dynamics.

Or not. Math more complex than quadratics gives me migraines.

For every force, there is an equal force applied in the opposite direction.

Oscillation isn't going to give you thrust, because each cycle is going to balance the previous one out.

Unless they produce actual vector generation formulae, I'm smelling 'Hoax'.