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How the Wiimote Works

Zonk posted more than 7 years ago | from the little-tiny-marios dept.

135

The New York Times' 'How it Works' series touches on a remote with a twist: the Nintendo Wiimote. The article describes the micron-sized machines that make it work, displays cut-away graphics of the little white marvel, and rounds out the discussion with a breakdown of where the tech came from. From the article: "The controller's most-talked-about feature is the capacity to track its own relative motion. This enables players to do things like steer a car by twisting the remote in the air or moving a game character by tilting the remote down or up. 'This represents a fabulous example of the consumerization of MEMS,' the tiny devices known as micro-electro-mechanical systems, said Benedetto Vigna, general manager of the MEMS unit at STMicroelectronics, a leading maker of the accelerometers embedded in the controllers. (Nintendo itself declined to talk about the controllers' inner workings.) He said the motion sensors, using the technology that activates vehicle air bags, can accurately sense three axes of acceleration: up and down, left to right, and forward and backward."

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Wait... (5, Funny)

Anonymous Coward | more than 7 years ago | (#17325368)

can accurately sense three axes of acceleration: up and down, left to right, and forward and backward.
Wait, isn't that six axes? Oh, I guess it's just Sony that likes to make shit up.

Re:Wait... (0, Redundant)

cHALiTO (101461) | more than 7 years ago | (#17325428)

No, it's three AXES. What you're talking about are DIRECTIONS.

Re:Wait... (2, Funny)

jizziknight (976750) | more than 7 years ago | (#17325466)

*WHOOSH*

You might want to have your sarcasm detector checked.

Re:Wait... (1)

cHALiTO (101461) | more than 7 years ago | (#17326404)

Damn, I think it broke again.. sorry about that.

Re:Wait... (2, Funny)

Daemonstar (84116) | more than 7 years ago | (#17325476)

But naming the SIXAXIS the SIXDIRECTIONS just doesn't have the same appeal.

Re:Wait... (1)

Total_Wimp (564548) | more than 7 years ago | (#17327310)

Besides motion sensing, both the PS3 and Wii controlers use Bluetooth. I can't help but remember a while back when Slashdot and others were saying Bluetooth is dead [google.com] .

I'm personally hoping this mainstream use and the improvments in version 2, will lead to more mice, keyboards and other devices that use it. It would be nice to have it built right into desktop PCs like it is in some notebooks. Being able to easily use your Wiimote or sixaxis on the PC, or your wireless keyboard and mouse on the consoles, would be great (though I doubt they made it this functional at launch). It could do away with needing to buy two steering wheels to play driving games on your console and your PC and could even let you use your phone's Bluetooth headset in gaming, or your more comfortable gaming headset for your phone around the house.

Can we finally say that the death of bluetooth talk is, well, dead? I hope we will so people can start using it to it's full potential.

TW

Re:Wait... (1)

ectal (949842) | more than 7 years ago | (#17327406)

They should have called it the ++DUALSHOCK2--

Re:Wait... (1)

tprime (673835) | more than 7 years ago | (#17329652)

Yeah, it's extra cool that you can spell it FORWARDS and BACKWARDS. Just the name itself is TWOAXIS

(for those two slow S I X A X I S = S I X A X I S backwards)

Re:Wait... (1)

EnglishTim (9662) | more than 7 years ago | (#17325444)

The six axes I think refers to being able to sense acceleration in each axis plus rotation around each axis.

Re:Wait... (2, Informative)

jizziknight (976750) | more than 7 years ago | (#17325504)

Rotation, however, does not denote an axis. Conventionally, in spatial geometry/physics, an axis represents a dimension.

Re:Wait... (2, Funny)

EnglishTim (9662) | more than 7 years ago | (#17325570)

I agree, but calling it threeaxesandthreedimensions doesn't get you a snappy palindromic name.

Re:Wait... (4, Funny)

blincoln (592401) | more than 7 years ago | (#17326948)

I agree, but calling it threeaxesandthreedimensions doesn't get you a snappy palindromic name.

That's why they should have called it something super-awesome like Axis of Threevil.

Re:Wait... (1)

Headcase88 (828620) | more than 7 years ago | (#17329310)

Ironically, the Wii Remote + Nunchuck has six axis (three for each) while the SIXAXIS only has three. But Nintendo didn't call their controller the SIXAXIS because they have some sense. The name is palindromic, but it's not snappy; it's awkward to say, and yet Sony probably spent billions in marketing dollars trying to think of a cool name, ending with one that isn't cool and isn't even technically correct.

But you could (0, Offtopic)

everphilski (877346) | more than 7 years ago | (#17327298)

but you could define three orthornormal axes for the accelerometer and three orthornomal axes for the gyroscope, which would be ... wait for it... sixaxis. We do this all the time in the aerospace world because you don't always mount the accelerometer and the gyroscope in the same manner. Each set of axes can be defined by a 3D vector and related by a 3x3 matrix.

Re:But you could (0)

Anonymous Coward | more than 7 years ago | (#17327332)

There is no gyroscope in either the Wiimote or the sixaxis controller...

Re:Wait... (1)

arodland (127775) | more than 7 years ago | (#17327308)

Actually rotation is exactly what's denoted when you say "axis". It comes from the same root as "axle". Every rotation comes free with an axis and a magnitude. The use of axes as reference points in a coordinate system draws on an analogy with the more concrete axes of rotation or revolution.

That said, there are still only three of them in the case of the PS3 controller, even if it can sense rotation about and motion along those three axes. But nobody would have bought the 6DoF.

Re:Wait... (1)

timcrews (763629) | more than 7 years ago | (#17325528)

Perhaps the phrase you are looking for is "degrees of freedom".

Re:Wait... (1)

EnglishTim (9662) | more than 7 years ago | (#17325594)

True, but it doesn't excite marketing as much :-P

Re:Wait... (1)

AcidLacedPenguiN (835552) | more than 7 years ago | (#17325894)

ouch. . . that burn caused MASSIVE DAMAGE!

Re:Wait... (1)

beckerist (985855) | more than 7 years ago | (#17325708)

Wow...

The only six axes I know about are the kind you buy with a gun!
http://209.85.165.104/search?q=cache:Olqst_zslZgJ: www.gutenberg.org/files/16349/16349.txt+%22six+axe s+and+a+gun%22 [209.85.165.104]

Re:Wait... (0)

Anonymous Coward | more than 7 years ago | (#17326854)

So... do you just not know that axes is the plural of axis? Or are you trying to make a joke that just wasn't funny?

Re:Wait... (1)

Thansal (999464) | more than 7 years ago | (#17325748)

as was pointed out, it is 3 axis, however it tracks movement and twist around each.

Then again, so does the WiiMote.

The article does not add anything new to our knowledge of how the nifty little toy works, and it does leave out the fact that the wiimote track rotation as well as movement.

Re:Wait... (1)

cnelzie (451984) | more than 7 years ago | (#17325866)

It can actually sense (at least) 4-Axis motion, do to the ability of the remote to sense a spin along it's centerline.

    Take a Wiimote, watch the hand pointer on the screen and rotate the Wiimote along it's centerline axis. The pointer hand will rotate on the screen along with the rotation of the Wiimote.

Re:Wait... (1)

webrunner (108849) | more than 7 years ago | (#17325972)

There's an accelerometer and the pointer.

The accelerometer returns acceleration along 3 directions, with relation to the remote. This allows it to detect tilt by figuring out which way gravity is, giving it 3 rotational axises.

The POINTER system can determine a) how far off in what direction the sensor bar is from where the remote is pointing, b) how far away from the sensor bar the remote is and c) The rotation of the remote with respect to the sensor bar.

THis means the wiimote basically has two ways to detect rotation along that one axis, incidentally.

Re:Wait... (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326400)

That doesn't sound right.

The accelerometer returns acceleration along 3 directions, with relation to the remote. This allows it to detect tilt by figuring out which way gravity is, giving it 3 rotational axises.

How can you infer gravity's direction purely from the local linear accelerations? If your acceleration vector is , okay, you know which way gravity is. But what if your acceleration vector is ? Which component is due to me moving the WIimote and which component is gravity?

Also:

The POINTER system can determine ... c) The rotation of the remote with respect to the sensor bar.

Yes, it *can*, but if you'll notice, the Wiimote knows your tilt, even when not pointed at the screen. I suspect there is a separate tilt sensor, similar to what they have on planes.

Oh, and anyone know why there isn't yet a game that tries to find your wiimote's absolute location at all times by integrating accelerations from the last known data from the sensor bar? Or one that allows you to calibrate to your screen size? (No, Zelda doesn't count, that's just horizontal.)

CORRECTION (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326434)

In my last post, I missed that the vectors were hidden because I used the tag containers.

The first should be [0,0,-9.8] and the second should be [15,15,15].

Re:Wait... (1)

Mr. Hankey (95668) | more than 7 years ago | (#17326834)

FWIW, Red Steel calibrates your screen size by having you point at objects in the beginning. Integrating acceleration information with previously known absolute information is prone to error from what I've seen, even with significantly more expensive systems, but using just the relative information is a reasonable approximation when you're playing a game.

Re:Wait... (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326890)

FWIW, Red Steel calibrates your screen size by having you point at objects in the beginning.

The fish thing? That's not really a calibration. That's just telling you to move *its* assumed pointer location onto *its* objects. That has nothing to do with whether *its* assumed pointer location is where you're really pointing.

Re:Wait... (1)

Eternauta3k (680157) | more than 7 years ago | (#17327566)

Oh, and anyone know why there isn't yet a game that tries to find your wiimote's absolute location at all times by integrating accelerations from the last known data from the sensor bar?
Drift.

Re:Wait... (1)

grumbel (592662) | more than 7 years ago | (#17330712)

### How can you infer gravity's direction purely from the local linear accelerations?

Games that use tilting for anything important don't expect the player to make any motions, so getting gravity in those games is easy since the motion vector is always [0,0,0] and the gravity vector is the only thing you ever see. Combining exact tilt with full motions should however get pretty tricky, might even be pretty much impossible for any real world scenarios.

### I suspect there is a separate tilt sensor, similar to what they have on planes.

Nope, there is just the accelerometer and the sensorbar, no other sensor in the Wiimote. That the sensorbar can detect tilt in one axis is simply the result of having two (or more) IR dots. available, tilt detection in racing games works via the accelerometer, the tilt info from the sensorbar might be used for those funny pointer rotations.

### Oh, and anyone know why there isn't yet a game that tries to find your wiimote's absolute location at all times by integrating accelerations from the last known data from the sensor bar?

Because its pretty much impossible to do, you don't even get exact tilt/motion information with the Wiimote, trying to use that already inexact data to estimate an absolute location would result in a mess. I don't expect to ever see true 1:1 mapping in any Wii game, since its simply impossible with the available sensory, the closest you can get is shown in WarioWare and Elebits.

Re:Wait... (1)

Some_Llama (763766) | more than 7 years ago | (#17327398)

"Take a Wiimote, watch the hand pointer on the screen and rotate the Wiimote along it's centerline axis."

I will do that as soon as I GET ONE!!! sheesh thanks for reminding me that I can't *sobs*

Re:Wait... (1)

LordKronos (470910) | more than 7 years ago | (#17331090)

It can actually sense (at least) 4-Axis motion, do to the ability of the remote to sense a spin along it's centerline.

Ummm...no, that would still be the 3rd axis, running from you to the tv (if you are holding it in a normal remote control orientation), and the movement would be known as roll. The other rotations (and axis) are yaw (around the axis from floor to ceiling) and pitch (along the axis from your left to your right). The other 3 degrees of freedom are the translations along those same 3 axis.

Re:Wait... (1)

miro f (944325) | more than 7 years ago | (#17328824)

I believe sixaxis involves three axes of movement and 3 axes of rotation, making 6 total.

Shhh... don't tell anyone these are the same three axes!

Little low-tech for SlashDot, eh? (2, Insightful)

xxxJonBoyxxx (565205) | more than 7 years ago | (#17325436)

How the Wiimote Works


C'mon, "editors"...this is SlashDot, not Time. Most people here could probably have written that article blindfolded. How about a couple of real tech articles today?

Not troll (2, Insightful)

UbuntuDupe (970646) | more than 7 years ago | (#17327078)

I'd M2 that unfair.

Time is very dumbed down, and uses slang my middle school English teacher wouldn't allow. That's for non-technical articles.

The NY Times article doesn't tell us anything we didn't already know.

Re:Not troll (3, Funny)

Lectrik (180902) | more than 7 years ago | (#17328158)


Time is very dumbed down, and uses slang my middle school English teacher wouldn't allow. That's for non-technical articles.


That's not very nice. I mean they named you as "Person of the Year" after all, didn't they?

Re:Not troll (2, Funny)

UbuntuDupe (970646) | more than 7 years ago | (#17328182)

Me? I thought they named you!

Re:Little low-tech for SlashDot, eh? (1)

MrBandersnatch (544818) | more than 7 years ago | (#17328856)

Ill bite Wii Internals [sparkfun.com] .
Have a good luck arounnd WiiLi [wiili.org] for more Wii goodness.

Air bags? Perfect! (5, Funny)

Zero Degrez (1039938) | more than 7 years ago | (#17325452)

This just in.

Nintendo is using their wiimote technology to determine when the wiimote flies from the users hand, and will now deploy an airbag before striking your HDTV.

Please return your wiimote for the new version with the wiirbag.

Re:Air bags? Perfect! (1, Funny)

Anonymous Coward | more than 7 years ago | (#17325898)

You mean "Wiibag", surely. Or "ColostoMii Bag".

only three axis? (4, Funny)

abigsmurf (919188) | more than 7 years ago | (#17325462)

The sixaxis must be twice as good! Either that or Sony failed geometry...

Eightaxis (1)

gregtron (1009171) | more than 7 years ago | (#17325842)

Someone should tell Sony that thier controllers are also moving through time. Maybe they'll release a clock upgrade to make it an EightAxis.

Re:Eightaxis (1)

ectal (949842) | more than 7 years ago | (#17327624)

Wow. If the controllers could move backward and forward in time, I'd finally be interested in a PS3.

Re:only three axis? (1)

Derekloffin (741455) | more than 7 years ago | (#17327560)

I might find this funny... IF you had got it right. There are 6 axis: 3 rotational, 3 directional. Is this so hard to understand?

Re:only three axis? (1)

LKM (227954) | more than 7 years ago | (#17330750)

You listed the same three axes twice. Is that so hard to understand?

Re:only three axis? (1)

bunbuntheminilop (935594) | more than 7 years ago | (#17329010)

SIXAXIS rolls off the tounge a lot better than SIXDEGREESOFFREEDOM

Re:only three axis? (2, Funny)

Jesus_666 (702802) | more than 7 years ago | (#17330854)

SIXAXIS rolls off the tounge a lot better than SIXDEGREESOFFREEDOM

But the latter might be more appealing to people whom like to watch FOX News etc. "The Wii gives you motion tracking, but does it give you FREEDOM?"

Then again, Americans might object to getting their freedom from Japan...

I heard... (0)

Anonymous Coward | more than 7 years ago | (#17325464)

I heard that the lifespan of a MEMS accelerometer is usually on the range of 10^15 oscillations, which disappoints me GREATLY.

Re:I heard... (1)

MuChild (656741) | more than 7 years ago | (#17326032)

Yeah, cause when you become an immortal cyborg you're going to want to take your wii with you as you travel into the inter-galactic void.

Re:I heard... (1)

Bill Wong (583178) | more than 7 years ago | (#17327146)

Assuming ten thousands oscillations a second, that's a life span of 3171 years or so. A million oscillations a second gives 31 years. I'm pretty sure it doesn't need to oscillate any much faster then a few kHz though...

Analogies rule!!! (5, Interesting)

jibster (223164) | more than 7 years ago | (#17325474)

These accelerometers are so sensitive, Mr. Vigna said, because electrons -- those subatomic particles that whirl around the nucleus of atoms like a video game in the making -- can sense the subtle atomic-level movement of the silicon structures.
Even for /. that's a messed up analogy. How is an electron like a video game in the making? Or is it the whirling around the nucleus that resembles the video game creation process?

Re:Analogies rule!!! (2, Insightful)

eln (21727) | more than 7 years ago | (#17325624)

Endlessly spinning in circles, never actually getting anywhere? Sounds like a pretty typical development environment to me.

Re:Analogies rule!!! (1)

Thansal (999464) | more than 7 years ago | (#17325822)

Only if you follow games like Dikatana and Duke3D.....

and zelda, and Valve games....

and..

oh alright, you win.

Re:Analogies rule!!! (1)

camperdave (969942) | more than 7 years ago | (#17326018)

... and the more you try to peg something down, the more uncertain the rest of the thing is.

Re:Analogies rule!!! (1)

steveo777 (183629) | more than 7 years ago | (#17327004)

I'm still wondering what the electron is doing whirling around in the nucleus.. How the hell did it get in there?!

Re:Analogies rule!!! (2)

ThinkWeak (958195) | more than 7 years ago | (#17325640)

So that's how they do it? I always thought video games were made with magic.

Re:Analogies rule!!! (1)

7Prime (871679) | more than 7 years ago | (#17326712)

Fairy dust and female pheromones... I believe.

simplified "how it works" (5, Funny)

Speare (84249) | more than 7 years ago | (#17325482)

I thought the Wiimote worked like this:

If you see a monster, throw the Wiimote directly at the monster. Depending on your aim, the monster will die in a shower of bright sparks and crackly noises, or the monster will hurl various objects back at you such as books, chunks of plaster, ceiling fan blades, or your little brother's eyeball.

Re:simplified "how it works" or why U dodge (1)

WillAffleckUW (858324) | more than 7 years ago | (#17326956)

If you see a monster, throw the Wiimote directly at the monster. Depending on your aim, the monster will die in a shower of bright sparks and crackly noises, or the monster will hurl various objects back at you such as books, chunks of plaster, ceiling fan blades, or your little brother's eyeball.
--


I always use a +2 Wiimote for my games.

Re:simplified "how it works" (0)

Anonymous Coward | more than 7 years ago | (#17328788)

Wiimote, apply directly to monster.
Wiimote, apply directly to monster.
Wiimote, apply directly to monster.

Imagine the possibilities (2, Funny)

Rosco P. Coltrane (209368) | more than 7 years ago | (#17325484)

independent researchers have shown that there is a strong link between very high voltages coming from the accelerometers and the state of inebriation (and perhaps low IQ) of the player...

No disassemble!! (1, Funny)

Rob T Firefly (844560) | more than 7 years ago | (#17325486)

So did they actually use tools to open the Wiimote up carefully? Or did they fling it with all their strength at an HDTV to get both an article, and piece of the class-action? [slashdot.org]

Didn't Live Up To The Hype (2, Informative)

Anonymous Coward | more than 7 years ago | (#17325526)

After having used my Wii and the controller for a couple weeks now I've been somewhat disappointed with the technology.

First, the Wiimote isn't an absolute pointing device. It's all relative to the Wiimote bar you place near your TV. Everything is relative to that device, so you are never actually pointing accurately at anything on your screen.

Second, the Wiimote has accuracy/responsiveness issues. Not sure if it is interference from bright lights or some other type of wireless/electronic devices. There are times where you are having to repeat the same motions over again because the Wiimote isn't registering.

Nothing fatal, but the hype certainly has worn off. Hopefully Nintendo will be coming out with updates to make the Wiimote more consistent in registering input over the next year.

Re:Didn't Live Up To The Hype (4, Informative)

Daemonstar (84116) | more than 7 years ago | (#17325602)

It's all relative to the Wiimote bar you place near your TV. Everything is relative to that device, so you are never actually pointing accurately at anything on your screen.
That's because the bar provides the infared source so the Wiimote has a frame of reference for the TV screen. Since it provides the infared source, anything that may alter the source will interfere with the Wiimote (i.e.: shiny surfaces like a coffee table, glass, mirrors, etc.). Of course, it is also why you can substitute the bar for 2 candles [wiihaveaproblem.com] .

Not informative (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326592)

That's true, but that's not what he was talking about. (Well, he was, but not in the part you quoted.) He was talking about how the place where you're really pointing is not the same as where it thinks you're pointing, and you can verify this yourself.

If you stand close to the TV -- not so close that it goes haywire, but close -- you'll see that it thinks it's pointing way off, depending on how you point, and usually in the vertical direction it's the most severe. And unlike the sibling poster said, this has nothing to do with its sensitivity. It has to do with the fact that the ONLY information you are allowed to give it about the sensor bar (in Wii options) is whether it's above or below the screen. WHAT???? It doesn't allow you to give it ANY more information about the real boundaries of your screen, which would allow the OS to have some trivial transformation to make it line up perfectly.

To be sure, this isn't a problem for a lot of applications. For one, as long as you are allowed to see where it THINKS you're pointing, and it's not miles off, it's perfectly functional. Also, for more than about ~8 feet away, the error is very small. But if they want to have a game like, I don't know, Time Crisis or House of the Dead, where you're not supposed to have the luxury of knowing where you're really pointing until you fire, it falls short.

A game could calibrate this, but I only know one that does -- Zelda -- and that's only horizontal, not vertical, which is the bigger problem.

BEFORE YOU MOD TROLL, let me just say that I love playing the Wii, but it bothers me to no end that they didn't put in a very trivial step that would vastly increase functionaly. Sure, I can understand them not *forcing* you to calibrate like that on startup, but to not even bury it under some advanced options?

Re:Not informative (4, Interesting)

Telvin_3d (855514) | more than 7 years ago | (#17326694)

Why would you want to have to calibrate it for the TV? The way it is set up right now, it is all relative. It doesn't have to aim exactly where you are pointing, it just has to change its position based on your movements in a consistent manner. The way it is now, i can go from a 23 inch TV to a 9 foot wide projector image with absolutely no calibration. Plug it in and go. That's really special.

Re:Not informative (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326736)

Why would you want to have to calibrate it for the TV?

Well, that's my point. You *shouldn't* have to. I completely agree with allowing the simple "above or below" quick setup. My complaint was that it doesn't allow you to provide it more information so that it can use a different algorithm, if you desire, that is more accurate for your particular screen. And the "consistency between screens" isn't necessarily good. It means if I have a smaller-than-usual screen (a pitiful 23'', poor me) I have to keep my pointer within a much smaller range to play Red Steel -- which isn't good.

Re:Not informative (1)

HappySqurriel (1010623) | more than 7 years ago | (#17326884)

The problem with it "becoming chaotic" if you sit too closely is that the Wiimote has to see both IR sources at the same time in order to tell where it is pointing; if you go too far away you would have a similar problem as the Wiimote would see both IR sources as one light source (I'd assume this would probably happen at quite a distance. Nintendo designed the Sensor bar to be optimal in most situations (between 6 and 15 feet from the television I would assume) but if that doesn't work well for you (and you're technically inclined) you could easily produce your own sensor bar by using 10 IR LEDs ( http://ledsupply.com/l2-0-ir5th30-1.php [ledsupply.com] ); cut the gap between the IR sources from 1/2-2/3 for sitting close and 1.5 to 2.0 times for sitting far away.

At the same time if you have too many more IR sources in the area (say from the sun on your TV or what not) you could always double up on LEDs and reduce the sensitivity to nothing. It sucks that Nintendo didn't make the bar more adjustable (by increasing the number of LEDs and allowing you to adjust the size), and it sucks that you'd have to create your own if your problems are too consistent, but this doesn't seem like it would be too complicated of a problem that a mod couldn't fix it.

Re:Not informative (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326950)

Did you understand what I was talking about in my previous post? I'm not having "problems". My Wiimote is doing exactly what it's designed to do. The problem has nothing to do with hardware either. The two IR sources suffice to figure out where it's pointing. My complaint was that the Wiimote takes its view of the IR's, and uses a pre-defined formula for placing the crosshairs, when really it should allow you to give it more information about where your screen really is, so it can modify the formula so that the crosshairs are closer to where you're really pointing.

Re:Not informative (1)

JonnyCalcutta (524825) | more than 7 years ago | (#17329318)

Shooting games (House of the Dead, etc) would no doubt work they way they always have, by reading the pixel colour on the screen. Any motion sensing madness is really just a bonus - and I guess would all help in the calculation and maybe make it more accurate. Its not like you haven't been able to buy gun based games on older systems, like the Dreamcast.

Also, it wouldn't surprise me if you larger/more powerful sensor bars were on sale at some point in the future - if not from Nintendo, then from 3rd parties. I suspect the reason for its size is simply that it has to be generic and fit TVs right down to 14" portable jobbies. It seems like to good an opportunity too ignore, though - offering larger sensors for bigger screens.

Re:Not informative (1)

UbuntuDupe (970646) | more than 7 years ago | (#17329852)

Shooting games (House of the Dead, etc) would no doubt work they way they always have, by reading the pixel colour on the screen. Any motion sensing madness is really just a bonus - and I guess would all help in the calculation and maybe make it more accurate. Its not like you haven't been able to buy gun based games on older systems, like the Dreamcast.

Well, my point was that, if calibrated, the Wiimote could know where you're really pointing, *without* having to read the pixels on the screen. It would just need to see the IR emitters and then apply the transformation based on the screen boundary specifications you gave.

I know you can buy a light gun. But wouldn't it be a lot better if the Wiimote actually applied its capabilities so you didn't have to get one? It could even handle House of the Dead 4, which requires the gun to sense shaking.

Re:Not informative (2, Insightful)

KDR_11k (778916) | more than 7 years ago | (#17330756)

I assume the firmware is trying to keep it simple so people won't get confused by basic settings. A game that needs correct aim could always add those calibration options (of course it'd be better if the firmware could store that config so you don't have to redo it for every game, maybe once the lightgun games come out Nintendo will consider adding it to the firmware).

Re:Didn't Live Up To The Hype (4, Informative)

nuggz (69912) | more than 7 years ago | (#17325614)

If your wiimote is a little off make sure you check the sensitivity to calibrate it.
I found that made a huge difference.

Re:Didn't Live Up To The Hype (1)

MobileTatsu-NJG (946591) | more than 7 years ago | (#17325786)

It has been suggested before, but try re-calibrating your remote. I have 3 friends with Wii's, at least two of them would have bitched non-stop if they had the problem you're having.

Re:Didn't Live Up To The Hype (5, Informative)

El Gigante de Justic (994299) | more than 7 years ago | (#17326476)

First, the Wiimote isn't an absolute pointing device. It's all relative to the Wiimote bar you place near your TV. Everything is relative to that device, so you are never actually pointing accurately at anything on your screen.

I don't think it ever was lauded or presented as an absolute pointing device prior to its release, but it is a very good ubiquitous pointing device and not simply a one trick pony as something like the Zapper was. As stated by others before me, this is because the sensor bar emits the IR which the wii-mote triangulates its pointing position from. It definately works best on the top of the TV, IMO. Ideal setup can vary depending upon whether you are typically sitting or standing, how high your TV is relative to the ground/seat, etc. Calibrating it is important too -- in my mind, that's one of the things that killed Red Steel - you can only calibrate at the very begining of the first level and not from the pause menu while pointing is an essential part of the controls. In Zelda:TP, you can play entirely without using the pointer and it still has a more advanced calibration option than the beginning of Red Steel available at all times (if only you could turn down the tingling fairy sound).
      It would not be possible to have an absolute pointer that would work on all TVs; they would have to actually sell a Wii TV (a Wii-V?) with the IR beams behind the screen to make an absolute pointer. The reason the Zapper and other light guns worked as something like an absolute pointer is because the tech was different, and as I understand it will not work on some modern TVs (I can't recall if its LCD or Plasma). When you pulled the trigger on the Zapper, the screen flashed black for a frame, and the area around the target sprites flashed white after that to indicate a target. The photo-receptors in the Zapper would detect that different to determine a hit or miss. Would you really want the screen flashing right with every shot in any modern FPS? The problem with using something like an invisible later pointer is that TV screens are not flat, and are usually convex. To do a reflective pointer you would ideally want a concave screen with the player at the focal point. By using IR and having each Wii-mote figure out its own position, you don't have to worry about different controllers interfering with each other's signals, etc.

Second, the Wiimote has accuracy/responsiveness issues. Not sure if it is interference from bright lights or some other type of wireless/electronic devices. There are times where you are having to repeat the same motions over again because the Wiimote isn't registering.

If you're having accuracy/responsiveness issues with the pointer, your most likely culprits are 1) other bright lights (including sunlight) in your gaming area 2) Other heat sources that aren't lights in the gaming area (i.e. laptop with running harddrive on the coffee table) 3) possibly reflective surfaces, but doubtful. If you aim your Wii-mote away from the screen and happen to pass another heat source like a candle or laptop, it may temporarily focus on that for triangulation, causing all sorts of problems, so keep your gaming area free of IR sources that can distract the remote. Lights should only be a problem if they are also a significant heat source (incandescent bulbs), and darkened rooms are better for gaming anyway.
      I haven't had any obvious problems with Wi-Fi, but it and Bluetooth do operate in the same range, as do most cordless phones. If you're having response problems regularly, try changing the set channels on your Wireless router and/or cordless phones.
      As for response issues with other motions, I have occasionally noticed some problems (like with batting in Wii baseball), where the bat seems way off, but if you go back to a base position and restart your motions, it usually comes out just fine. One of the tricky parts to motion recognition is determining which motions were deliberate and which are casual motions not meant to take an action. I much more often accidentally do something with a casual motion than have actions go undetected.

Pointing IS accurate (1)

rev063 (591509) | more than 7 years ago | (#17327602)

I thought the same thing as you when I first got my Wii. It seems like you're just moving the Wiimote to get a sympathetic motion of the cursor, but that the Wiimote isn't actually pointing at the cursor. For me, it feels like I'm pointing a bit below the on-screen cursor.

But try this: hold the Wiimote up to your eye, and look along the Wiimote like using the sight on a handgun. In actual fact, it lines up perfectly, at least for me. It just doesn't feel like it does. I'm not sure why.

Re:Pointing IS accurate (0)

Anonymous Coward | more than 7 years ago | (#17327950)

Sweet cheese, what's all this silly noise about?? Where do you people keep your computer mouse? On your screen? Or directly in between you and the screen? Who cares if the wiimote is off by a few inches from the actual display on the screen? It still does what it's supposed to do.

Re:Pointing IS accurate (1)

grumbel (592662) | more than 7 years ago | (#17328926)

### Who cares if the wiimote is off by a few inches from the actual display on the screen? The problem is simply that adding proper calibration that would fix this issue once and for all would be trivial, but all the Wii offers is a generic "Above/Below TV" settings, which of course can't give you accurate Wiimote->Cursor pointing.

Re:Pointing IS accurate (1)

Aladrin (926209) | more than 7 years ago | (#17328296)

I've done that. Mine is not even close to accurate. The best I can get is if I put the bar right under the edge of the display. At that point, 2 inches top and bottom are not considered screen and pointing at those areas is 'off screen' to the wiimote.

The Wiimote does not calibrate for the size of the TV, so it -cannot- be accurate on all TVs. Apparently somewhere around 33" is about right.

I suspect this would not be nearly so annoying if my TV was smaller than that, as you tend to overshoot when you are excited. But having to restrict my motions instead is annoying.

I'm still hoping for an OS update that adds calibration for TV size. I think that would fix most of the problems I have with the Wiimote.

Re:Didn't Live Up To The Hype (0)

Anonymous Coward | more than 7 years ago | (#17329760)

First, the Wiimote isn't an absolute pointing device. It's all relative to the Wiimote bar you place near your TV. Everything is relative to that device, so you are never actually pointing accurately at anything on your screen.

That makes no sense, try replacing Wiimote with mouse:
First, the mouse isn't an absolute pointing device. It's all relative to the mousepad you place near your computer. Everything is relative to that device, so you are never actually pointing accurately at anything on your screen.

This is really going to kill the uptake of the mouse :)

Some points (1)

LKM (227954) | more than 7 years ago | (#17330932)

It's all relative to the Wiimote bar you place near your TV

Well, duh. The Remote can't know where you place your TV, or how big your TV is. That's why there is a sensor bar. Games are free to calibrate your remote, though, so that the "TV offset" is corrected. So far, none do this. You could fix this by creating your own wider or smaller sensor bar - I thought about creating a small white sensor bar I can place inside my projector's picture.

The responsiveness issues seem to depend on the games. Some have a pretty big lag, some don't. It never bothers me during gaming, though, I only notice it when I'm moving the hand.

Lastly, I think you're confusing the accelerometer and the "pointing mechanism." The fact that the Wii sometimes doesn't register your motions has got nothing to do with bright lights or interference. It's simply you not making the correct motions. Motion sensing does not depend on the sensor bar.

I'm totally happy with my Wii. I'm playing it at least one or two hours every day, since I got it on Europe launch day. I have friends over every second day, and five of them have already bought or ordered their own Wiis (and the number would be higher if more Wiis were available). I pronounce the Wii "best console ever."

Re:Didn't Live Up To The Hype (0)

Anonymous Coward | more than 7 years ago | (#17331130)

That's because all the fancy new TVs don't have a trace. So there's nothing for lightguns to "see".

Blame it on your newfangled technology. I certainly do. You damn LCD and Plasma people ruined it for us CRT people.

This article sounds a lot like... (0)

Anonymous Coward | more than 7 years ago | (#17325664)

This article sounds a lot like this [slashdot.org] slashdot story of a few weeks ago entitled "The Mechanics of Motion Sensing"...

And the firmware is available too.. (1)

thrill12 (711899) | more than 7 years ago | (#17325808)

..to the Wiimote [sparkfun.com] - at least reversed from the eeprom on the device. This should improve the compatibility of PC's to the Wiimote, and I hope we see some interesting applications on the PC soon ; that or Nintendo should release a Wii-SDK, otherwise I think they are definitely losing a whole lot of interest in the long run of the more adventurous type of user who longs for interesting applications for this simple (proven) but now widely available concept of three-axis sensing devices.

Motion or angle? (2, Insightful)

seebs (15766) | more than 7 years ago | (#17326084)

I'm a bit confused. The ability of the Wiimote to sense the angle it's at seems quite consistent, and doesn't appear to be possible to "fool", while the ability to sense motion can be fooled somewhat.

It seems to me that they must be separate, at least a little. You can walk away with a Wiimote, far out of bluetooth range, turn it however you like, bring it back... And the console will still sense its orientation precisely. Location? Games that use that sometimes get out of sync so you have to wave the Wiimote around a bit to get them better calibrated.

So I'm pretty sure that's a separate feature, to say nothing of the additional component of the CCD pointing at the IR sources above your TV to give you a pointing device.

Re:Motion or angle? (1)

Khakionion (544166) | more than 7 years ago | (#17326278)

Depends on what you mean by orientation. If you mean the rotation of those pointers like in the Main Miinu (haha, get it?), that's calculated using the Sensor Bar, erroneously named as it is.

Re:Motion or angle? (2, Informative)

HappySqurriel (1010623) | more than 7 years ago | (#17326588)

I'm a bit confused. The ability of the Wiimote to sense the angle it's at seems quite consistent, and doesn't appear to be possible to "fool", while the ability to sense motion can be fooled somewhat.

There is a reason for that ...

The Force of Gravity will always register as an (aproximately) 9.81 M/(s^2) acceleration to the acclerometers inside of the Wiimote; this means that you should be able to tell it's orientation in comparison to the ground pretty easily.

I'm a bit confused. The ability of the Wiimote to sense the angle it's at seems quite consistent, and doesn't appear to be possible to "fool", while the ability to sense motion can be fooled somewhat.

Personally, I'm not sure what you mean by "fool" the ability to sense motion though ... For the most part, the Wii accepts a wide variety of input largely because the games have to be useable with small motions for a 3 foot tall child / little person and also usable with large motions for a 7 Foot tall adult. If Tiger Woods Golf (as an example) had a swing clinic to test your real golf swing, I doubt it would be easy to trick it with a wrist flick.

Re:Motion or angle? (1)

UbuntuDupe (970646) | more than 7 years ago | (#17326844)

The Force of Gravity will always register as an (aproximately) 9.81 M/(s^2) acceleration to the acclerometers inside of the Wiimote; this means that you should be able to tell it's orientation in comparison to the ground pretty easily.

Unless, of course, I'm accelerating it such that the vector appears equal in all directions or something.

Re:Motion or angle? (1)

heinousjay (683506) | more than 7 years ago | (#17328848)

I suppose that would do the trick, but the onlyh situation I can imagine where this would happen would be an explosion. I wouldn't count blowing something up as fooling it.

Re:Motion or angle? (1)

UbuntuDupe (970646) | more than 7 years ago | (#17329798)

Equal in all three *axes*, moron. As in, an acceleration vector of (15,15,15). They don't actually have to be equal, though. They could be (15,-20,-2) or something. Now, how does it infer gravity from those acceleration vectors?

Re:Motion or angle? (0)

Anonymous Coward | more than 7 years ago | (#17327032)

9.81 M/(s^2), is that the same as 9.81 kHz^2 ?

Re:Motion or angle? (0)

Anonymous Coward | more than 7 years ago | (#17329300)

No.

Re:Motion or angle? (3, Interesting)

acidblood (247709) | more than 7 years ago | (#17326970)

Having done some inertial engineering work, I can shed some light on this issue.

The Wii-mote has accelerometers on it. These sense forces applied to it (gravity included), and their combined output is a vector indicating the direction and modulo of the resultant acceleration. Assuming you're standing still, you'd only be subject to the force of gravity, and by definition it always points to the ground. So do a few vector computations and you know the orientation of the Wii-mote. There is a problem with a `blind axis' (rotation in the same axis as gravity can't be detected), but ignore that for now.

On the other hand, if you want to estimate position, here's what you have to do: given an initial position, read the accelerometers, subtract the effect of gravity from the acceleration vector (harder than it seems, since the Wii-mote could be pointing anywhere, really), which then gives the `real acceleration' of the system. Now integrate this once to obtain velocity, and again to obtain position. There's just so much room for error here, that I don't know where to start. Limited accelerometer resolution, poor A/D converters, temperature drift, numerical accuracy issues, you name it. Integrating measurements (not only that, but integrating twice!) is just a recipe for disaster. Then there's a fundamental limitation to accelerometer devices: rotations can't really be distinguished from translations. Just think about it -- a given resultant acceleration vector could be the result of pointing the Wii-mote in any given orientation, added to a specific acceleration in a specific direction. You just don't have enough information to distinguish between the two -- not with accelerometers alone, at least.

Hope that helps.

Re:Motion or angle? (1)

UbuntuDupe (970646) | more than 7 years ago | (#17327286)

I don't understand. In the second paragraph, it sounds like you're saying the accelerometers can tell which way gravity is, but in the second, you're saying it can't distinguish it from the acceleration due to the motion of the Wiimote.

Re:Motion or angle? (0)

Anonymous Coward | more than 7 years ago | (#17327496)

Exactly!

If you take the wiimote (in the right position) and swing it around in a circle *at the right speed) the accelerometers would not be able to distinguish between that and moving the wiimote up and down.

It only senses changes in speed (i.e. acceleration!). Not position, not angle. Angle is inferred from the accelleration due to gravity, but it's not very accurate if you're moving the wiimote around at all.

When the wiimote can see the sensor bar, it has additional info to tell distance and angle (though the camera itself can't tell if the wiimote is upside down - there is no encoding of the left/right led on the sensor bar) so it knows where the wiimote is pointing relative to the bar.

Re:Motion or angle? (1)

tprime (673835) | more than 7 years ago | (#17329816)

Wow.. Does anyone remember the classroom scene in Better Off Dead where Lane draws the picture of a pregnant woman when he is supposed to be figuring out a complex math problem? Just before that the teacher jokingly rattles off an explanation to a difficult mathematical quandry and it sounds soooo easy that if you didn't get it you were stupid. After reading that last post, I felt like a moron for not having a freaking clue.

I am glad there are smart people out there, because I know that if it were up to my intelligence only, I wouldn't have lasted this long.

Re:Motion or angle? (1)

Anti_Climax (447121) | more than 7 years ago | (#17329906)

Then there's a fundamental limitation to accelerometer devices: rotations can't really be distinguished from translations. Just think about it -- a given resultant acceleration vector could be the result of pointing the Wii-mote in any given orientation, added to a specific acceleration in a specific direction. You just don't have enough information to distinguish between the two -- not with accelerometers alone, at least.
I thank you for your knowledgeable post. Out of curiosity, if they were using more than one 3-axis accelerometer like this one [fujitsu.com] would they still have difficulty with determining pure rotation from other movements?

The one missing feature (2, Informative)

J-1000 (869558) | more than 7 years ago | (#17326532)

While I love the Wiimote and Nunchuk, I think they really suffer from the lack of at least a single-axis gyroscope. The accelerometer is great for measuring tilts in relation to the earth's surface, but they can't register angles on axes perpendicular to the earth's surface. This makes it more difficult to register a camera pan to the left or right, for instance, without involving the IR sensor.

The most obvious use (to me) for such a feature would be to have the Nunchuk pan the camera left and right as you point it left and right (in FPS games for instance), but it would also improve situations like batting and swordfighting where you want the instrument onscreen to match the angle of the Wiimote as closely as possible.

What? (0, Troll)

drinkypoo (153816) | more than 7 years ago | (#17326780)

He said the motion sensors, using the technology that activates vehicle air bags

This is fucking hilarious. I will proceed to let you know precisely how most vehicle air bags are activated.

It is true that in the more modern vehicles there is ONE accelerometer per direction of air bag. This is used to set off air bags other than the front. There is usually one accelerometer to set off the front air bag.

HOWEVER this is not the only input. In fact it takes two inputs to set off the air bag. One input is that accelerometer sensor. The other input is either crash sensor mounted in or near the front bumper.

This is the hilarious part - these sensors typically consist of a magnet, a ball bearing, a ramp, and a set of contacts with another magnet. A sufficient shock will break the ball bearing free of the magnet, at which point it rolls up the ramp (again, if the shock is enough) and sticks to the other magnet, closing the switch contacts.

So what this guy is saying is that the technology in the Wiimote utilizes is a combination of an accelerometer and a ball bearing rolling up a ramp.

Seatbelt? High-tech shit! --Carlin

So Nightshot anyone? (0)

Anonymous Coward | more than 7 years ago | (#17327156)

So I need to ask, if I turn on the nightshot in my sony camcorder, am I going to screw up people playing with their wii?
(Nightshot emits an IR beam)

Could I make an IR device to screw up my friends with just an IR LED?
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