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Using Hacked Wiimotes As Scientific Sensors

samzenpus posted more than 4 years ago | from the graduated-joystick dept.

Hardware Hacking 110

garg0yle writes "Scientists are repurposing Wiimotes as scientific sensors to help measure wind speed or evaporation from lakes, among other things. At about $40 per unit, the controller is much cheaper than specialized sensors. The scientists are still considering how to add storage and extend the battery life."

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Is this what the University of East Anglia is usin (2, Funny)

Anonymous Coward | more than 4 years ago | (#30453074)

to detect global warming?

"scientists" (2, Insightful)

Anonymous Coward | more than 4 years ago | (#30453110)

Seems like more of an engineering challenge than a scientific one.

Re:"scientists" (3, Insightful)

fuzzyfuzzyfungus (1223518) | more than 4 years ago | (#30453288)

While you can get a fair amount of science kit off the shelves these days, "science" has always involved a good bit of engineering, if you want your experiments to actually happen.

Sometimes there is an explicit division of labor, sometimes the same person performs both functions.

Re:"scientists" (2, Insightful)

HNS-I (1119771) | more than 4 years ago | (#30455584)

Clifford Stoll:

The first time you do something it's science, the second time it's engineering, the third time it's just being a technician.

Re:"scientists" (1)

JWSmythe (446288) | more than 4 years ago | (#30453614)

    Everything's an engineering challenge, it all depends on how you look at it. :)

    Sometimes that's half the fun.

    The other half is enjoying the result.

    Come on, let your mind sink to the gutter. It's more fun here. :)

Oh Science. (4, Insightful)

Interoperable (1651953) | more than 4 years ago | (#30453144)

“There are probably better ways to measure wind, but it was a day well-spent,” Hut said. “I really felt the need to solder something.”

A day well-spent indeed! There's nothing like spending a day to save a few dollars by not having to buy a specialized sensor. Sounds like my Master's research; why buy good equipment when grad students can spend ages building a poor imitation of it? Still, those days are usually the most fun part of "science" and certainly afford excellent learning opportunities.

Re:Oh Science. (4, Funny)

Shakrai (717556) | more than 4 years ago | (#30453160)

There's nothing like spending a day to save a few dollars by not having to buy a specialized sensor.

They won't be saving any money when they get hit with the DMCA lawsuit ;)

Re:Oh Science. (0, Redundant)

MindlessAutomata (1282944) | more than 4 years ago | (#30453172)

They've done nothing to break the DMCA.

Re:Oh Science. (0)

Anonymous Coward | more than 4 years ago | (#30453190)

whoosh

Re:Oh Science. (1)

MindlessAutomata (1282944) | more than 4 years ago | (#30453254)

Except many other companies have been playing around with using Wiimotes, and software is freely available to use your wiimote on your computer and no DMCA notice has been served. Nintendo typically doesn't serve DMCAs notices like shadier companies do.

Re:Oh Science. (0)

Anonymous Coward | more than 4 years ago | (#30453284)

Whoosh!

Re:Oh Science. (0)

Anonymous Coward | more than 4 years ago | (#30460422)

It's an automata, give it a break.

Re:Oh Science. (1)

TrancePhreak (576593) | more than 4 years ago | (#30453620)

Not for the purpose of using Wiimotes on computers, no. However, Nintendo is quick to attack any and all flash cart manufacturers.

Re:Oh Science. (1)

internettoughguy (1478741) | more than 4 years ago | (#30453304)

They may well have broken the EULA though.

Re:Oh Science. (1)

Thinboy00 (1190815) | more than 4 years ago | (#30453296)

DMCA == software/data
Wiimote == hardware

Re:Oh Science. (1)

Z00L00K (682162) | more than 4 years ago | (#30454794)

It does contain software, but if you don't modify it and just use it "as is" then you are hardly messing things up.

Just download Wiimotelib [brianpeek.com] and you can start hack your application.

And I recently succeeded in interfacing the Wiimote with a Windows Mobile - using the StoneStreet Bluetooth stack, so it's not impossible - even if the general consensus until now has been that it isn't possible.

Re:Oh Science. (0)

Anonymous Coward | more than 4 years ago | (#30453544)

There's nothing protecting copyrighted works here and they are certainly not trying to circumvent anything.

Re:Oh Science. (0)

Anonymous Coward | more than 4 years ago | (#30453228)

except that,
grad students are like 50x cheaper than the specilized sensor, so a day working on this is still cheaper.

Re:Oh Science. (1)

interkin3tic (1469267) | more than 4 years ago | (#30454864)

A day well-spent indeed! There's nothing like spending a day to save a few dollars by not having to buy a specialized sensor.

Looking at the image, I have to wonder why a lab would need to buy or build a "Toy plastic boat" sensor of any type.

There is a toy plastic boat right there. I saw it. I'm surprised they couldn't find a grad student capable of doing that. Really speaks poorly for the quality of our education system.

Re:Oh Science. (1)

xaxa (988988) | more than 4 years ago | (#30457744)

A day well-spent indeed! There's nothing like spending a day to save a few dollars by not having to buy a specialized sensor.

Looking at the image, I have to wonder why a lab would need to buy or build a "Toy plastic boat" sensor of any type.

There is a toy plastic boat right there. I saw it. I'm surprised they couldn't find a grad student capable of doing that. Really speaks poorly for the quality of our education system.

It floats, cost €2, and they could add an LED really easily. Then they can measure the water level in the tank as the water evaporates, which was the problem they were trying to solve (and the data is better than using the "proper" instruments).

Re:Oh Science. (1)

interkin3tic (1469267) | more than 4 years ago | (#30460500)

Then they can measure the water level in the tank as the water evaporates, which was the problem they were trying to solve (and the data is better than using the "proper" instruments).

But can it measure the WOOSH?

Re:Oh Science. (1)

V!NCENT (1105021) | more than 4 years ago | (#30455484)

Not to mention the fact that with a day worth of salary you can buy a tenfold of these things...

It's like driving ten extra miles to a store where you can get a 5 dollar discount. "Yeah but I save 5 dollers!" -"Yeah and you pay 6 dollar worth of fuel, you complete retard!"

Sorry for the obviousness and the rant, but hey, this is the internet :)

Re:Oh Science. (1)

smooth wombat (796938) | more than 4 years ago | (#30457594)

It's like driving ten extra miles to a store where you can get a 5 dollar discount. "Yeah but I save 5 dollers!" -"Yeah and you pay 6 dollar worth of fuel, you complete retard!"

Let's break out this charge and see how it really works (yes, I'm being a pedantic twit, but it's worth the effort in this case):

The average price per gallon of gas in the U.S. is $2.65. My car, a 1998 Honda, gets, on average, 33 mph doing my normal driving. If I have to drive to an extra ten miles to save $5 on something, that means it costs me, roughly, .89 cents to drive one way. Doubling that, round trip, means I'm spending $1.78 to save $5.

Or, put another way, I'm still saving over $3 on that particular item when fuel costs are calculated in.

Obviously, if you're driving an SUV or truck, then it is not worth your effort to save that $5 since your fuel mileage is substantially worse than mine and any savings in cost is negated by the cost of fuel used to drive that distance.

Re:Oh Science. (1)

j00r0m4nc3r (959816) | more than 4 years ago | (#30459072)

It's like driving ten extra miles to a store where you can get a 5 dollar discount. "Yeah but I save 5 dollers!" -"Yeah and you pay 6 dollar worth of fuel, you complete retard!"

If it costs you $6 in fuel to drive 10 miles, I would say you are the retard.

Re:Oh Science. (1)

CaptDeuce (84529) | more than 4 years ago | (#30458316)

There's nothing like spending a day to save a few dollars by not having to buy a specialized sensor. Sounds like my Master's research; why buy good equipment when grad students can spend ages building a poor imitation of it?

research assistant n. see indentured servant

I know that "why" is a rhetorical question. But... too bad grad students don't work on grant budgets. :-) Having wrestled with said budgets in Excel (before someone with a bussiness degree took over), I can tell you that the amount of money allocated to equipment tends to be rather flexible. Any give in the budget tends to be used for junket... er, travel expenses for attending scientific conferences.

It's not about how much it costs to make (4, Insightful)

Anonymous Coward | more than 4 years ago | (#30453150)

...this equipment can run $500 or more...

The scientific equipment is more expensive because laboratories are willing to pay more, and have the money. Gamers aren't willing to pay $500 for a controller.

Look here: Digikey [digikey.com] has 18000 pressure sensors available. I picked one [digikey.com] at random, and it can measure pressure up to 115 psi, which is about 60 meters deep in water. It only costs $12. I could make you the serial port/USB interface for like 20 bucks.

Scientists only pay that much because they are willing to pay that much.

Re:It's not about how much it costs to make (5, Insightful)

Psaakyrn (838406) | more than 4 years ago | (#30453258)

However, you're underestimating the cost of time. Mass production decreases both the cost and time of making a specific product (or combination of products).

Re:It's not about how much it costs to make (5, Funny)

gmhowell (26755) | more than 4 years ago | (#30453596)

However, the cost of a grad student per hour is asymptotic at $0.

Re:It's not about how much it costs to make (0)

Anonymous Coward | more than 4 years ago | (#30455850)

Arguably, this is an oddity of the US system.

and it's not entirely true (1)

name_already_taken (540581) | more than 4 years ago | (#30456866)

I work with a number of professors at several universities, and they have to pay their grad students for time spent on the projects we fund. I don't know what the hourly rates are but they're enough that when one project temporarily ran out of funding, the grad student took a job waiting tables at a restaurant. This suggests that the pay is in a similar range as what a waiter makes. Not a lot, but not $0 either.

I remember it well because the prof told me that when he got his next funding increment he had to go down to the restaurant and get his grad student to come back.

If you're a grad student and you're doing research work for $0, well, I hope the work will look really good on a resume.

Re:It's not about how much it costs to make (1)

L4t3r4lu5 (1216702) | more than 4 years ago | (#30455892)

I roughly equate the rate for student employment to being one day's work is equal to one night's worth of beer in the Union bar.

So, around £1.50 per hour. £10 will get you a lot of beer at 90p a pint.

Re:It's not about how much it costs to make (1)

2obvious4u (871996) | more than 4 years ago | (#30457336)

Actually grad students pay you to build it. I don't know about you, but I had to pay for my education.

Re:It's not about how much it costs to make (1)

wooferhound (546132) | more than 4 years ago | (#30453678)

>Mass production decreases both the cost and time of making a specific product

Sounds like Nintendo could make some pretty nifty scientific instruments just my making small changes to the Wiimotes and mass producing them.

Re:It's not about how much it costs to make (2, Insightful)

SleazyRidr (1563649) | more than 4 years ago | (#30454388)

Which brings us back to the problem of a market that is too small.

Not enough people are doing high-end research to make it worth Nintendo's (or anyone's) effort to produce them on a mass scale.

Re:It's not about how much it costs to make (4, Informative)

Mr. Freeman (933986) | more than 4 years ago | (#30453592)

That, and the fact that a lot of scientific instruments are of the quality needed to do science. Sure, your bathroom scale is $20, but that won't do you any good when you need to measure masses on the order of one tenth of one milligram. Even a 3-place "precision" balance for $200 won't cut it for a lot of work. You need a 4-place analytical balance, which will run you about $4k.

Cheap sensors work great for things like wind speed and the water level of a lake because any small variation in these readings means absolutely nothing.

Now, as for the wiimote being an amazing tool, it's really not. It's being touted as such by scientists who apparently aren't actually examining how this thing works.

The case in the article mentioned using it to measure water level by using the IR camera on the sensor to record an IR beacon on a floaty thing in the water. You can do the same thing with a cheap ass digital camera and the same laptop that reads the data from the wiimote for about $10-15. They also mention putting wiimotes on a collapsing building to gather data. This is because the wiimote contains a chap accelerometer which you can actually buy on sparkfun.com for much cheaper than an entire wiimote.

Apparently these guys have never heard of embedded devices. The arduino, PIC microcontrollers, and NI DAQ devices have been around for years and would perfectly suit the purpose of data collection. As I'm attending an engineering university currently I've noticed something. Engineers seem to be much more up to date and logical about what's PRACTICAL. Sure, you could use a wiimote, but you could get an arduino, a flash drive, and some cheap accelerometers for about $50 and you could use it to collect AND PROCESS five times the amount of data and use it on orders of magnitude more applications.

Re:It's not about how much it costs to make (4, Interesting)

idolcrash (836925) | more than 4 years ago | (#30453694)

This is because, for the most part, scientists are focused on their research subject and their area of expertise, cost reduction, not so much. You can't really expect everyone everywhere (especially outside of engineering) to know the intricacies of arduinos, NI DAQs, etc. as well as how to best implement them. That's for the engineers, really, and having and extra engineer on the research team most likely costs more than the savings they could help with...plus I'm not sure how many, say electrical engineers, would be interested in that kind of work anyways.

Re:It's not about how much it costs to make (1)

cheesewire (876598) | more than 4 years ago | (#30456424)

Solution: collaborate.

I know, I know. Obviously beyond any real-world scenario in academia.

Join the real world sometime... (1)

name_already_taken (540581) | more than 4 years ago | (#30456912)

Solution: collaborate.

I know, I know. Obviously beyond any real-world scenario in academia.

Actually, collaboration is very strong in US universities. At work we are constantly hearing about some research project or other being helped out by someone from a different department who brings new or unique skills or methodologies to the project.

What is not favored however, is falling behind schedule on your grant-funded research because you're waiting for some weenie to hack together an experimental sensor from scratch when you can go down to Gamestop and buy one for $39.

It's not about how much it learns me. (0)

Anonymous Coward | more than 4 years ago | (#30460248)

"That's for the engineers, really, and having and extra engineer on the research team most likely costs more than the savings they could help with...plus I'm not sure how many, say electrical engineers, would be interested in that kind of work anyways."

Quite a few. Some of the same things that drive scientists drives engineers. A quest for knowledge and solve problems.

Re:It's not about how much it costs to make (1)

confused one (671304) | more than 4 years ago | (#30453878)

Turns out people are interested in real-time tracking of small variations in environmental data. USGS and NOAA, to name two, pay for 0.1% accuracy or better in their instruments. I have an 0.01% barometer sitting in my desk drawer.

Re:It's not about how much it costs to make (3, Insightful)

hairykrishna (740240) | more than 4 years ago | (#30455468)

So the accelerometer set up you propose would cost about the same as the wiimote only they'd have to build it from scratch and write some software for it? Plus, why would you want to process the data on board? You're not doing anything with it immediately. I see your point about the camera though. What res are wiimote cameras?

Re:It's not about how much it costs to make (1)

Spatial (1235392) | more than 4 years ago | (#30458932)

What res are wiimote cameras?

128x96 @ 100hz.

Re:It's not about how much it costs to make (1)

ctmurray (1475885) | more than 4 years ago | (#30453670)

In industry we are willing to trade money (which we have sometimes) for time (which we are always short of). Since I don't know how to take the sensor and wire it up to a USB port (nor do I know anyone in my lab who can do this) it would take me well over $500 in hourly wages to learn this skill and produce this sensor. As mentioned in another post, academic situations allow for undergrad and grad volunteer (or slightly paid) to spend the time and learn some valuable skills. If anyone at my work needs help with neutron scattering, I can draw upon my grad school experience.

Now I do appreciate others hacking things like the Wii and providing instructions and software to create new sensors.

Re:It's not about how much it costs to make (2, Informative)

confused one (671304) | more than 4 years ago | (#30453844)

You got your units wrong. That's a 115 kPa sensor, or 16.7 PSIA. It's a barometer; a baro of 1.5% accuracy. A waterproof UL / IS / FM approved water level transducer in a rugged welded stainlesss steel casing in roughly the same accuracy range (1%) will cost you a few hundred dollars.

Re:It's not about how much it costs to make (1)

willy_me (212994) | more than 4 years ago | (#30458036)

Scientists only pay that much because they are willing to pay that much.

No, that is not the reason. It is essential that scientific experiments can be repeated by scientists at other universities. Because different sensors can take readings differently, that means the equipment used must be readily available to all. It also requires that a listing of equipment used must be included in any publications that result from the acquired data. Saying that you captured measurement 'x' with some custom hardware is only acceptable if you had a really good reason for requiring custom hardware. And in that case, full schematics and firmware code must be provided.

At the end of the day, it is simply much easier to take readings with tools made by established manufacturers. It is less expensive to buy the horribly overpriced equipment then to develop your own and prove to the scientific community that the results are valid. Even a simple temperature measurement can be made horribly complex when you have to detail the accuracy and account for external factors such as humidity. Too much is invested in research to have a year of work questioned as a result of trying to save a couple hundred dollars.

So scientist would love to save money on equipment. But they are not simply purchasing devices that take measurements - they are purchasing devices that take measurements with known amounts of error.

As it stands, you are probably like me. It pains me to see people in my office (biologists) spend ridiculous amounts of money on sensors. I know it would take me less then a day to whip up sensors that perform the same task as the $500 sensors they purchase. It was only after talking to them about their sensors that I started to understand the reasons why they do it. They do not pay lots of money simply because they are willing to - it is actually required.

Other Sensor Platforms (5, Interesting)

Tisha_AH (600987) | more than 4 years ago | (#30453162)

I think the pricing of scientific instrumentation is based largely upon the limited number of devices produced. The folks who make sensors really do not care too much about the price and are looking at recovering their development, manufacturing and marketing costs off of very small sales quantities.

A case in point; I work with AMI (SmartGrid) systems for measuring water and electricity consumption. These devices have a surprising level of sophistication, very long battery lives (10-20 years off of a Li-Ion battery) and can store a data-point every fifteen minutes and report it back across a radio network. I "know" the manufacturing costs are down in the $30-60 range for each device. The manufacturers are all anxious to get customers (utilities) to spend their millions on projects to put SmartGrid technologies into cities so the more you buy, the cheaper they get. The data is frequently coming from "absolute encoders" on water meters and less frequently, from pulse encoders that generate a certain number of pulses per 1000's of gallons (the device counts them up, multiplies them by a K factor and gives you a corrected value for gallons of water consumed).

The Nintendo Wi is a good example. How many millions of the Wi devices are made? If they were $250 each there would not be many consumers buying them so they mass-produce and keep the prices low. You see the same effect when you hear about banks of PlayStation 3's being used in clusters for supercomputing.

Re:Other Sensor Platforms (3, Informative)

Attila Dimedici (1036002) | more than 4 years ago | (#30453472)

The pricing of scientific equipment also reflects several other factors (not to say that some scientific equipment isn't overpriced): first, there is very high quality control. Scientific equipment generally goes through fairly rigorous quality testing. Second, and more importantly, any device that is used to capture scientific data for electronic storage must comply with 21 CFR part 11 if that data will be submitted to a regulatory agency in the U.S. (and similar regulations if it will be submitted to regulatory agencies in the E.U., Canada, Japan or several additional countries which I don't know the identity of off the top of my head).

Re:Other Sensor Platforms (4, Interesting)

tlhIngan (30335) | more than 4 years ago | (#30454350)

And the flipside happens too - scientific instruments are used for cooking. In this case, it's for cooking delicate foods using a thermal immersion circulator to cook sous-vide.

http://gizmodo.com/5346014/what-is-this [gizmodo.com]

It's used because it's the best way to do precision temperature control.

Re:Other Sensor Platforms (1)

drinkypoo (153816) | more than 4 years ago | (#30456490)

It seems like Arduino+XBee is the answer for stuff like this, at about $100/3pk of ATM328+Xbee boards; you get a repeating mesh-network and yes, very good battery life. I have a hard time believing that using Wiimotes and then adding battery to them and so on is going to be any cheaper, especially if you're calculating for the cost of development time.

Scientific Value of Wii, PS3, XBox 360? (2, Funny)

Psaakyrn (838406) | more than 4 years ago | (#30453234)

I'm curious on the non-game advances the Wii, PS3, and XBox 360 has provided for the community.

The Wii advances via it's mass-produced controller, the PS3 advances via mass-produced mini-computer, the XBox 360... um... (need some help here).

Re:Scientific Value of Wii, PS3, XBox 360? (0, Offtopic)

BradleyUffner (103496) | more than 4 years ago | (#30453274)

the XBox 360... um... (need some help here).

The fact that its a good gaming system.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

PitaBred (632671) | more than 4 years ago | (#30453468)

For certain values of "good" that don't include banning for playing a non-hacked game and exploiting a bug in the software, as well as locking out 3rd party peripheral storage... yeah, that's a GREAT gaming system.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

TrancePhreak (576593) | more than 4 years ago | (#30453672)

"that don't include banning for playing a non-hacked game and exploiting a bug in the software" [citation needed]

Of course you don't seem to realize that many of those third party storage units were being used to create exploits for games, or that not all 3rd party storage units were affected by the update.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

PitaBred (632671) | more than 4 years ago | (#30456694)

Non-hacked game banning [arstechnica.com]

The 3rd party peripherals, those are just a pure money grab. There's no reason for the drives to cost as much as they do other than Microsoft wanting to exploit lock-in.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

Thinboy00 (1190815) | more than 4 years ago | (#30453312)

Xbox 360 is pretty well DRM locked down, so no help is forthcoming.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

TrancePhreak (576593) | more than 4 years ago | (#30453656)

Says the person who doesn't know about XNA and the Creator's club.

Re:Scientific Value of Wii, PS3, XBox 360? (3, Funny)

Megane (129182) | more than 4 years ago | (#30453626)

The 360 advances via its mass-produced red LEDs.

Re:Scientific Value of Wii, PS3, XBox 360? (1)

GameboyRMH (1153867) | more than 4 years ago | (#30458710)

the XBox 360... um... (need some help here).

Provides endless comedy with its RRODs, massive overheating power brick, and user-phobic online gaming service.

details on the wind sensor (1, Interesting)

Anonymous Coward | more than 4 years ago | (#30453278)

are there any details for the wind sensor? It's only mentioned in the story but not linked to any additional information.

Anything goes... (2, Insightful)

MindPrison (864299) | more than 4 years ago | (#30453282)

...thats the beauty of science, we're not limited to "have to", but more what we could do - "because we can".

In amateur science circles, we also used commercially available TV-tuners as spectrum analyzers, instead of purchasing a commercial test-instrument that cost up to a 100.000 dollars, it could be made to perform pretty close and pretty well with some external circuitry for a few hundred bucks, made it affordable for the radio-amateur, science amateurs, and science students everywhere.

Absolutely LOVE to see people use the resources like the Wiimote like that, excellent!

So yeah - sky's the limit!

Power Glove (0)

Anonymous Coward | more than 4 years ago | (#30453306)

I am absolutely dying for someone (nintendo maybe even) to make a glove with a wii remote on each finger and thumb. Imagine the possibilities for interaction with a 3D environment with this. You'd be able to grasp things in the 3D space of your game, and your hands position could be tracked more accurately than any other device of a similar type has before. It would be an expensive piece of hardware, but I'd buy it if I could grasp a ball and throw it to another player in a networked game of... something where you throw balls at other players. It doesn't matter! It'd be great.

Re:Power Glove (1)

dikdik (1696426) | more than 4 years ago | (#30453360)

That could be cool, but keep in mind that the WiiMote has two modes -- accellerometer mode and infrared pointing mode.

Accellerometer mode is useful for things like shaking, tilting, and swinging. Sadly, it has almost nil information for determining where in space something actually is -- only how it's moving, and to back-extrapolate position from motion data is highly inaccurate.

The way Wiimotes get highly sensitive positioning data for things like aiming and driving is by using the secomd mode, whihc is the infrared sensor mode. This only works when the Wiimote is pointing at a dual infrared source (the "sensor bar" that hangs out by your TV). So if you point the Wiimote at the floor, the Wii has very little idea of how your Wiimote is actually oriented.

So what all this mumbo jumbo means for your PowerWiiGlove is that you would have to use accellerometer mode, and that it would make your glove highly inaccurate for detecting sensitive motion (such as manipulating VR objects). Your idea is highly feasible (especially with the advancements in small accellerometers that the Wiimote uses), but just not with the accellerometer configuration present in the existing Wiimote. In other words, your idea is good, but sit on it until Wii 2.0 comes out.

Re:Power Glove (1)

chuckymonkey (1059244) | more than 4 years ago | (#30453430)

If I remember correctly there is a cheap ($20) addon for the wiimote that has a gyroscope in it. I would imagine that it would give a better representation of its location in space. I'm not sure though if it is an actual gyro or if it's another set of accelerometers, either way I do know that it is much more accurate with relation to its position in a three dimensional space.

Re:Power Glove (1, Informative)

Anonymous Coward | more than 4 years ago | (#30453462)

It's a gyro. Really cool tech actually, in that it's completely solid state (like the accelerometers)

Re:Power Glove (2, Informative)

Zerth (26112) | more than 4 years ago | (#30453556)

More specifically, a tuning fork gyroscope [wikipedia.org] .

Apparently it is easy to read with i2c as a standalone part, too.

Re:Power Glove (2, Informative)

'nother poster (700681) | more than 4 years ago | (#30454434)

Yep. That socket in the bottom of a Wiimote is nothing but a proprietary i2c interface connector. You can get accelerometer, button, and joystick input from a nunchuck with a $2.50 Atmel microcontroller. I don't know if they still have them, but sparkfun used to have a little adapter board to let you connect a Wiimote accessory to a .1" pitch 4 pin header.

Re:Power Glove (3, Informative)

Nyeerrmm (940927) | more than 4 years ago | (#30454660)

While a gyro is necessary to actually do full 6-DOF position tracking (otherwise you must assume that you're holding a specific orientation... this can still be good for something like an in-the-air mouse), the Wii system still wouldn't be good for detecting absolute motion without the sensor bar as well.

The problem is that while the sensors are fairly precise as far as measuring the accelerations (if they're anything like the iPhone sensors they're around 0.02g precise), when you try and integrate them twice to get the position, things start to fall apart. Imagine you do a simple up-and-down motion. You get a sinusoidal acceleration curve that when you integrate it once gives you an offset sinusoid to represent your velocity, and a second integration gives a third one to represent your position. However, at the end, your integration to the velocity level comes out to be not quite zero, because those small acceleration errors will mostly cancel out, but not perfectly. This is still a pretty good velocity estimate, since its close to zero. However, as far as your position is concerned, close to zero and actually zero are very different, so you get a constant, growing drift in your position from a small velocity error. The same things apply to gyros, although the math is a little more complex.

Basically if you want to use a sensor as a double integrator it has to be extraordinarily precise, and even then you're going to get some drift that you have to remove every once in a while, or have an absolute position value to keep it in check (kalman filters do a great job of interpreting data from multiple sensors). What the sensor bar and IR sensors do is give you an incomplete but useful reference on position and orientation that you can use to keep that drift in check. Adding the gyros definitely helps a lot too, but you still need the sensor bar to keep drift in check.

Re:Power Glove (1)

c6gunner (950153) | more than 4 years ago | (#30453470)

So what all this mumbo jumbo means for your PowerWiiGlove is that you would have to use accellerometer mode, and that it would make your glove highly inaccurate for detecting sensitive motion (such as manipulating VR objects).

Or you could stick some LED's on the fingertips of the glove and point the wiimote at them. In fact, I could have sworn someone already did something like that.

Re:Power Glove (2, Interesting)

inode_buddha (576844) | more than 4 years ago | (#30453432)

it would sell if you had interactive pr0n games...

Re:Power Glove (1)

Cryacin (657549) | more than 4 years ago | (#30453436)

Like this one? http://en.wikipedia.org/wiki/Powerglove [wikipedia.org]

I remember hacking one of these as a kid when "Virtual Reality" first came out, and we did the same thing. Bucketloads of fun. Nintendo should probably review one of their previous commercial failures. At least they won't have any patenting issues. ;)

Re:Power Glove (1)

gmhowell (26755) | more than 4 years ago | (#30453612)

Like this one? http://en.wikipedia.org/wiki/Powerglove [wikipedia.org]

Did you miss the subject line of the post you are replying to?

fun but probably not that accurate (1)

the stapler (658635) | more than 4 years ago | (#30453322)

From my hours of research (read play) with a Wiimote, I'd question how accurate the data you'd get from a Wiimote would really be. Real scientific instruments can gather incredibly detailed data, and tons of it. I guess you get what you pay for.

Re:fun but probably not that accurate (1)

Nyeerrmm (940927) | more than 4 years ago | (#30453510)

In my experience, doing some sensor systems with cheap sensors and expensive sensors, the difference is that cheap ones can be fast or accurate, while good ones can be both. Because you can average data and apply statistical methods to eliminate noise, a long integration time can get you very good precision (as long as your not doing an integrator... using an iPhone as a position sensor won't work, since you can't average the acceleration to get it).

In this case, a cheap sensor is going to work quite well unless your trying to collect usable data faster than about 1 Hz. Its really a matter of knowing what you need. In many cases a cheap sensor works really well.

Re:fun but probably not that accurate (1)

Nyeerrmm (940927) | more than 4 years ago | (#30453524)

And forgetting my high school science classes, averaging gives you precision, not accuracy. Accuracy is a whole other issue, but its not very different between cheap and expensive sensors, and calibration can eliminate the issues.

Re:fun but probably not that accurate (2, Interesting)

pbrooks100 (778828) | more than 4 years ago | (#30456092)

In my experience, doing some sensor systems with cheap sensors and expensive sensors, the difference is that cheap ones can be fast or accurate, while good ones can be both. ... Its really a matter of knowing what you need. In many cases a cheap sensor works really well.

Using cheap sensors can allow you to validate your hypothesis. This can in turn help you justify the additional expense of calibrated and more precise sensors to accurately describe the relationship observed. (You can also use spares of the cheap sensor equipment to play games and blow off steam while the experiment is running; Mario Kart anyone? :)

Re:fun but probably not that accurate (1)

SleazyRidr (1563649) | more than 4 years ago | (#30454368)

Exactly, you do get what you pay for, so why pay for more than you need. I haven't RTFA but the type of science they are doing probably doesn't need to be all that accurate to get meaningful conclusions.

Funny coincidence (5, Interesting)

idolcrash (836925) | more than 4 years ago | (#30453350)

The lab I work in uses hacked Wiimotes to study visual pecerption in autism, Alzheimer's, and Parkinson's. They can be programmed with C#, which our PI and another undergrad learned to work with the Wiimotes...the ease of use and the hackability are pretty good selling points besides the price.

Re:Funny coincidence (1)

CraftyJack (1031736) | more than 4 years ago | (#30453858)

Plus, the Wiimotes are already safe for use around the general public, which must make your safety review a little smoother.

Re:Funny coincidence (1)

acohen1 (1454445) | more than 4 years ago | (#30459828)

This sounds very interesting. Do have any published work on that project or maybe a webpage?

Re:Funny coincidence (1)

idolcrash (836925) | more than 4 years ago | (#30460728)

I'll have to dig a bit, it is a pet project of one of the grad students.

TU1BGIRL (-1, Troll)

Anonymous Coward | more than 4 years ago | (#30453368)

the public eye: GNAA on slashdoT, I won't bore you

Extend the battery life (4, Informative)

Craig Davison (37723) | more than 4 years ago | (#30453388)

There's a few Wii battery packs out there that allow the controller to be powered over USB with a standard A to mini-B cable. Here's one:
http://www.dealextreme.com/details.dx/sku.4978 [dealextreme.com]
Of course, if you drain the battery pack faster than you can recharge it, you might have a problem.

Re:Extend the battery life (1)

bronney (638318) | more than 4 years ago | (#30453418)

Well then don't drain it. Get the 5V off the USB and give 3V to the terminals directly.

Re:Extend the battery life (2, Insightful)

nametaken (610866) | more than 4 years ago | (#30454446)

What I found interesting was that they were able to figure out the relatively complicated parts of performing the measurements and recording them in a way they can use later, and yet they still haven't worked out a larger battery?

Re:Extend the battery life (1)

Gordonjcp (186804) | more than 4 years ago | (#30454850)

Many many years ago, my dad got annoyed with constantly replacing the little coin cells in process timers at work - about one a week on average. So with the aid of a couple of short bits of wire and some hot-melt glue he stuck alkaline D cells on the back of each one. Over twenty years later (and some 16 years after he went silent key himself) most of the timers are still on their original D cells...

as long as you don't care about accuracy (1, Troll)

timmarhy (659436) | more than 4 years ago | (#30453580)

because why would scientists care about how accurate their data is when you can just accuse anyone questioning your study of being paid by big oil/monsanto/big pharma.

Re:as long as you don't care about accuracy (1)

Idiomatick (976696) | more than 4 years ago | (#30453776)

Different experiments require different levels of accuracy. The rest of your post is just a troll... Seriously, who disses scientific pursuit in general?

Re:as long as you don't care about accuracy (0)

Anonymous Coward | more than 4 years ago | (#30453854)

From what I've seen some republican religious conservatives do. I think they're afraid we might discover more facts which show their bible is false.

Re:as long as you don't care about accuracy (1)

timmarhy (659436) | more than 4 years ago | (#30454452)

i'm not republican, i have no religous affiliation what so ever and i support gay marriage so i'm hardly conservative.

your as bad as the people you accuse.

Re:as long as you don't care about accuracy (1)

SleazyRidr (1563649) | more than 4 years ago | (#30454354)

Anyone with any brains can clearly see that scientific pursuit is the work of the Devil. Everything we could ever need to know is in the Bible, which is completely correct, so much so that we don't even have to verify it.

Science what the Devil uses to undermine our faith in the one true Lord by implanting false assumptions into the heads of scientists, which they then go on to 'prove' via their 'scientific method'. Renounce science and save your soul before it's too late!

Re:as long as you don't care about accuracy (1)

evanbd (210358) | more than 4 years ago | (#30454046)

Making your own instrumentation is common. I've done it in an industry setting, though not in a lab; but I've heard about plenty of labs that build their own special-purpose instruments. The end result is that you have to calibrate it. Obviously you can't use something like this without at least verifying the calibration, but that can be very easy.

Once you've calibrated it, what's not to like about a piece of consumer electronics that does the job?

Re:as long as you don't care about accuracy (1)

Monkeedude1212 (1560403) | more than 4 years ago | (#30454142)

Clearly you don't know how accurate the Wii Sensor is. Any difficulties you have problems with the Wii mote on the Wii are part of poor setups and user error.

The Wii Mote itself has an excellent sensor built into it, It's just that the sensor bar is terribly concieved. All it does is emit 2 Infrared signals at either end. Generally, this does just fine, but your TV is also emitting heat, the room is warm, etc etc. There are people who do it with 2 candles a foot from both sides of their television screen and get alot more sensativity out of it.

You make that sensor track 1 item, pretty close to it,and you have an excellent sensor for $40.

Re:as long as you don't care about accuracy (1)

wvmarle (1070040) | more than 4 years ago | (#30454418)

There is accuracy.

Then there is reproducibility.

Those two are not the same.

The Wiimote measurements must be accurate for a proper gaming experience, but not necessarily reproducible.

This kind of measurements are nice if you wish to measure changes (change in water level), not if you wish to measure something absolute (the actual water level).

Re:as long as you don't care about accuracy (0)

Anonymous Coward | more than 4 years ago | (#30455142)

Anyone questioning your study can just get off their lazy asses, and go measure it themselves. That's how science has always worked.

Doesn't surprise me. We use them to Teach. (1)

The Infamous TommyD (21616) | more than 4 years ago | (#30453972)

I've been using them in my Computer Eng. Problem Solving class for 3 years.

Here's a vid where freshmen measure a drop (accounting for air resistance) using a wiimote.
http://www.youtube.com/watch?v=tPCBfyQP4eE [youtube.com]
I'd say they make a great instrument as long as you quantify your error.

Heres a power idea (1)

tengeta (1594989) | more than 4 years ago | (#30454420)

Two wires, solar panel. Bang.

That will teach Sony. (0)

Anonymous Coward | more than 4 years ago | (#30455304)

I'd bet they're thinking now that closing the PS3 wasn't such a great idea after all...

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