After Hours

Cracking open the Nintendo Wii Remote

See what is inside

Much has been written, speculated and conjectured about the Nintendo Wii Remote. As a follow-up to our disassembly of the Wii we decided to crack open the Wii Remote to see for ourselves. To our surprise, although in hindsight it shouldn't have been, the device maintains Nintendo's design theme of simple and functional.

© CNET Networks, Inc / TechRepublic
Mark W. Kaelin

 

About

Mark Kaelin is a CBS Interactive Senior Editor for TechRepublic. He is the host for the Microsoft Windows and Office blog, the Google in the Enterprise blog, the Five Apps blog and the Big Data Analytics blog.

29 comments
robke71
robke71

Hello, I have a problem with a controller. The motion from the controller is not stable. A another controller is good (stable). I open this unstable controller, but which part provides the motion? I hope that you can help me. Grtz.

LarryD4
LarryD4

Does anyone know what the expected lifetime of the remote is? I 've trashed some controllers in my youth from excesive playing. But with out springs I wonder how long Nintendo expects them to last. Also, anyone do any travelling with your Mii loaded to the controller?

Oscelot
Oscelot

You mention that the "Two chips with red arrows" are the most likely candidates for accellerometers... I'm going to have to disagree with you. My understanding is that there are no accellerometers in the main remote. The direction you are moving with the main remote is recieved, sent, and determined by the infra-red led/lsd on the front of the remote. The accellerometers that you are looking for are far more likely inside the Nunchuck remote. But either way, I'd bet you a nickle, that those chips don't contain a single moving part. If an accellerometer DOES exist in that remote, it's far more likely to be the large cylindrical black thingy on the other side of the board. Which interestingly enough appears to be the vibrator. (that speaker isn't the source of the vibration, it's not heavy enough) And to call the speaker a "sub woofer" is also a bit from left feild, simply because sub-woofers get their effectiveness from their enclosures more than anything. But hey, I'm just a sound engineer, what do I know?

read
read

Come on. If you're going to take the time to do this, and you plan to show the world, at least try to get most of the shots in focus.

jim
jim

You say the speaker is used as a subwoofer to generate vibration. I don't think so. You skipped over the wires coming off the back of the circuit board leading to a compartment in the back of the case--shown in the next to last picture. This, I expect, is the vibrator.

Mark W. Kaelin
Mark W. Kaelin moderator

Thanks for the link. Leave it to Popular Science to give a clear explanation. I just wish they would have pointed out where the chips are.

Mark W. Kaelin
Mark W. Kaelin moderator

Believe me I will defer to you on that. Like I said it was speculation and conjecture on my part. I don't have enough engineering prowess to test any theory. That being said, when I bowl on the Wii I'm not using the Nunchuck, yet the console still reads the motion of the Wii remote. The swinging of my arm means that the infra-red is pointing in the opposite direction at the top of my backswing. It would seem to me that something else is going on besides infra-red. If anyone has further insight, please lets hear it.

DavidRS1992
DavidRS1992

I'll agree with you there on the accelerometer perhaps being in the black cylinder thingy. Then again, it may be the thing making the Wii-mote vibrate. But if there are no accelerometers in the Wii-mote, how does it know how fast you're throwing the Wiimote down in bowling?

Mark W. Kaelin
Mark W. Kaelin moderator

I need to take a course in photojournalism I think.

custm42435
custm42435

The speaker does not vibrate.. AND.. THATS NOT A CAPACITOR IN THE PIC, THE BIG BLACK THING IS THE VIBRATOR.. DER!!!.. lol.. if it were a capacitor, then the pcb would be labeled "C##" with ## being a number for that particular cap, which it is not..

gs
gs

If anyone still cares, the accelerometer is an Analog Devices ADXL330. I believe the top red arrow (U4) is the part.

Oscelot
Oscelot

Wow, a fellow Albertan saves the day! Thanks for those links. As it turns out - the vibrator is in fact at the top/underneath side of the remote, The IR Rx/Tx on both the sensorbar and the remote work together (if you cover the remote IR lens on the main menu it stops working) But when it all comes down to it... Gyros, Excelerometers & IRs work together depending on how the games are designed to use them. Being a pilot, and understanding Gyros & Accelerometers the way I do - I'm skeptical about which chip is which, but I'm hardly an expert, so I'll stand corrected on that matter. The speaker (on the other hand) just isn't capable of producing the frequency necessary to vibrate the remote as much as the actual vibrator does. I don't need the microphone and elaborate testing items suggested in the other thread, to know that. However I do appreciate the "back-up" info. Suffice to say (for me at least) that Nintendo has created a great product with many MANY excellent features. I love it. :o) Cheers Folks!

jc williams
jc williams

If one has the chip numbers, you could figure out what is what. With that being said, the chips that you thought could be accelerometers, could actually be positional and strain detectors (a small weight secured between several peizo-contacts and measures the change in position/speed/direction). Those chips would be most likely set at 90 degrees from each other, as well as being set on the assumed center lines, to properly get the change update information as the device changes direction. The strain allows the determination of maximum sustain movement. Also, if the transmission is blue-tooth, then why would you need the IR interface???? If you start a back-swing (as in bowling), how does it determine your swing (unless it just tracks movement across the IR field of vision and calculates the information from there). Then again, why the bluetooth??? The black device is most likely the vibrator as an out of balance spinning weight is needed to create the rumble that would not be able to be created from such a small speaker (you need a very large speaker and lots of power to create sub 40 hertz rumbles). Here is something to try .... try bowling standing 90 degrees to the TV. Does it still bowl? I noticed that when I am pointing with the controller, it must be pointed at the IR receiver, but it does detect the roll of the hand. Different functions in the same device, depending on the applications? I don't know, however inquiring minds want to know :)

Oscelot
Oscelot

Mark, I have a suggestion for testing things... The next time you're bowling on your wii - simply put your free hand over the IR lense on the front of the remote. Also, if you pay careful attention to what's going on - you'll notice that when you click the button to let your mii know that you're ready to swing, he begins that swing without you. And only when you've ended up syncronized with his motion - does the ball delivery turn out ok. Now, to quote a wise man... "it's speculation and conjecture on my part", because I really haven't played it enough to test my theory (perhaps I should). But by simply "not moving" until after the mii is nearly done his delivery, or by covering up the infra-red lens, you'll soon find out whether it uses the IR or not. :o)

Oscelot
Oscelot

The speed of your arm motion can easily be calibrated by the infra-red sensor on the base unit as it compares the motion of the infra red beam transmitting from the remote. Accelerometers aren't good for determining speed as much as specific acceleration (g forces) in a particular direction. "having said that - an eccelerometer (could) measure speed but only while your hand is accelerating..." if you were to move an accelerometer at a constant rate in a constant direction - it wouldn't detect the motion. Regardless - the Infra Red sensor on the base unit is more than sufficient to detect any movement, direction and speed of the main remote. (so long as it's facing the tv(sensor).

ajn465
ajn465

The items you're trying to shoot are small and your camera doesn't seem to like shooting that close. If it has a 'macro' mode, that's what it's for. If not, crank up the pixel count and shoot from farther away, then use just about any photo program to crop 'em. One big reason for super high pixel-count cameras is to allow for clean cropping

mib.2945
mib.2945

The Wii-mote uses gyroscopic motion. You can sync the wiimote via bluetooth with a modified bluetooth stack on your pc, then run a pie script to convert the motions into movements and use it as a gyroscopic pointing device ala media center remote. This is done WITHOUT AN IR SENSOR BAR AT ALL. The IR sensor bar merely acts as a secondary feedback control to "fine tune" the responses the wiimote generates. You can operate it completely independent of the sensor bar. Now, onto the rumble device. A few minutes with a mic, oscilloscope, and a wiimote will tell you that it does NOT in fact generate any appreciable noise on ANY frequency while "rumbling" short of vibration against whatever surface its on. When pinioned in a felt cushion in the jaws of a vice, it returns next to no noise while "rumbling." That kind of defeats the idea of the speaker as a rumble device ja? It wouldn't surprise me if BOTH chips were part of the gyroscopic movement sensing. A solid state chip with an empty trace inside, filled with mercury, will return a finely callibrated motion sensor with no "moving" parts at all.

rdowdy
rdowdy

After reading several articles and testing with the Wii remote, it seems the remote only uses IR when pointing at the screen. It uses Bluetooth when transmitting info regarding the motion of the remote and button operation. I have bowled used the remote in a different room than the IR sensor and completely out of sight. Also, the IR sensor bar actually SENDS out IR signals the remote senses. People have hacked the sensor bar with batteries to make it wireless, you can also purchase wireless models that do not plug into the Wii at all. I do not know how the remote senses motion but it is not IR. Most games can be played off to the side of the sensor bar as you do not have to point at the screen to play them, i.e bowling and tennis.

Oscelot
Oscelot

So try this... hold the remote facing the TV, then rotate it (twisting) on the y axis... does the cursor twist as well? Yes. Ok - now put your hand over the entire face of the IR lens. Do the same twist, does the cursor still follow? There are 2 IR lenses on the base unit IR Receiver, so the "tilt" of the remote is easily enough covered assuming there are also two transmitters/LEDs on the remote. The SHAKING (on the other hand) gives us an excuse to believe there is a movement sensor inside the remote. If the black cylindrical "thingy" on the back of the circuite board is a vibrator, it "COULD" also be a motion sensor. Not likely an accelerometer, but but shaking the remote, you would be causing the magnetic components of the vibrator motor to generate a measurable current for the device to use for input data. OK, before we get too carried away with this duscussion... I don't want anyone to think I'm being argumentative or anything. I just think (given nintendo's track record)that this thing is much more simple than we're giving them credit for. What I mean is... Nintendo has typically taken the less expensive, and often simpler route to providing their products to the masses. And dont' get me wrong, I love my Wii. In fact - I'm going to play it and test my theory out right now. :o) Cheers Everyone!

techrepublic
techrepublic

Yes IR is used a lot, but there really must be an accelerometer, plus an orientation sensor. I've been playing wario ware smooth moves, one mini game has you cover the IR with your thumb and shake the wiimote like a bottle of champagne - removing your thumb is part of the action. Secondly, some minigames appear to know the approximate direction you're pointing even if this is off-screen, plus the yaw of the wiimote is certainly known (just rotate the wiimote in the wii menu, to see the cursor tilt). Anyway, enough conjecture - here's wikipedia: http://en.wikipedia.org/wiki/Wiimote

william
william

So how do they measure acceleration otherwise?

Rowan Hawkins
Rowan Hawkins

Other ideas would be to use a small mini tripod or a bag with rice or beans and a delay option if you camera has one, which would remove any blurryness caused by camera shake. In general I'd go with always using the highest resolution and then editing down since photo applications are better suited to editing than the camera is. For the same reason stay away from digital zoom. The red and blue fringing is a JPEG artifact from high contrast lines. Shooting farther back may help some. Also the auto focus will have an easier time dealing with the items in the image if they are closer to the same plane.

Mark W. Kaelin
Mark W. Kaelin moderator

You are right about the camera not liking close ups. Your idea about taking the photo at a distance with high resolution and them "zooming" in by croping it may be a good alternative. I'll give it a try - thanks.