How does the Wii know what the Nunchuk is doing?

[dsdavis]

I realize the nunchuk is attached to the Wiimote, but in boxing, for instance, how does the Wii know that you've punched with the nunchuk hand? It doesn't alway seem to respond as I expect it to, but overall it does seem to know when I've punched with it. Is there some wireless sensor in it? Otherwise, I don't see how the Wii would know you've punched with it.

Or maybe something that senses a rapid movement, and it sends that to the Wiimote through the wire.

 

[CantGetAWii]

Its motion based as well, similar to the Wiimote allowing for further functionality.

 

[tloztw]

i think its got something inside it that reacts to tilting, sort of like the gba wario ware

 

[LevesqueIsKing]

In the example you've provided, the nunchuk has the exact same technology as the wii-remote. That is, when pertaining to sensing motion. Although, the actual name of the piece of equipment has temperarily slipped my mind.

Keep in mind that WiiBoxing revolves around quick motions, and not actual punches. Turn remote to the side for hook, down for jab, or up for uppercut. This is usually agreed as one of the major downfalls of WiiSports, as it commonly confuses and discourages the gamer.

 

[gidget]

Although, the actual name of the piece of equipment has temperarily slipped my mind.

accelerators... :yesnod:

 

[Bigred]

accelerators... :yesnod:

No, accelerometers. The accelerator is the pedal you press to make a car go. Think about the word accelerometer. Meter of acceleration.

In the example you've provided, the nunchuk has the exact same technology as the wii-remote. That is, when pertaining to sensing motion. Although, the actual name of the piece of equipment has temperarily slipped my mind.

Keep in mind that WiiBoxing revolves around quick motions, and not actual punches. Turn remote to the side for hook, down for jab, or up for uppercut. This is usually agreed as one of the major downfalls of WiiSports, as it commonly confuses and discourages the gamer.

The nunchuck, like the wiimote, has a motion detecting device called an accelerometer. However, the nunchuck's accelerometers are not as advanced and sensitive as the wiimotes, which is why it doesn't respond as well as the wiimote does.

Or maybe something that senses a rapid movement, and it sends that to the Wiimote through the wire.

The information from the accelerometer is sent through the wire of the nunchuck into the wiimote, then the information is sent to the wii via bluetooth.

 

[wii_girliefairie]

Wow, Bigred, you know a lot.
*rep*

 

[rukus]

gremlins

 

[gidget]

accelometer... *burned into memory*

No, accelerometers. The accelerator is the pedal you press to make a car go.

accelerator... gasoline to light a fire :yesnod:

 

[Skorp]

accelerator, teehee

 

[dsdavis]

Thanks, all. Now it makes sense.

Here's info from Wikipedia:

Nunchuk
The Nunchuk (model number RVL-004) is the first controller attachment Nintendo revealed for the Wii Remote at the 2005 Tokyo Game Show. It connects to the Wii Remote via a cord that is about 3.5 to 4 feet (1 ~ 1.2 m) long. Its appearance when attached resembles the nunchaku, hence the name. It also features an analog stick similar to the one found on the Nintendo GameCube controller and two trigger buttons (a last minute modification changed the two triggers to one trigger and a "C" button, as described below). It works in tandem with the main controller in many games. Like the Wii Remote, the Nunchuk also provides a three-axis accelerometer for motion-sensing and tilting, but without a speaker, a rumble function, or a pointer function.[46][47] The Nunchuk's accelerometer is an STMicroelectronics LIS3L02AL.[48]

http://en.wikipedia.org/wiki/Wii_Remote#Nunchuk

 

[COLDshiver]

However, the nunchuck's accelerometers are not as advanced and sensitive as the wiimotes, which is why it doesn't respond as well as the wiimote does.

Both the Wiimote and Nunchuck use the same exact accelerometers, it's not less advanced nor less sensitive. The nunchuck just has one less.

 

[gidget]

which one is the nunchuk missing? seems to me it would need X & Y asix... is there another?

 

[Foxy]

Basically in the simplest form it detects tilt motions but a bit more complex.

 

[daley]

Warning - this gets kind of technical.

Each accelerometer is a three-axis device, which is capable of detecting acceleration in any of the three principal axes (X, Y, and Z, all of which are at right angles to each other). In other words, if you put a device with a single three-axis accelerometer on the table in front of you, it would know if you moved it side to side, toward or away from you, or lifted straight off the table, or any combination of these. What it wouldn't know, however, is if you rotated it. You could twirl it around to your heart's content and if you did it carefully so that it was always rotating around the accelerometer, it wouldn't have any idea that it was being moved. (OK, this is a slight simplification, but it's close enough for the discussion at hand.)

If you want to detect rotation, and just as importantly if you want to distinguish rotation from translation (which is the type of motion that you could detect with a single-accelerometer device), you need more accelerometers. In fact, if you want six degrees of freedom, which is rotation about any axis or combination of axes and translation along any axis or combination of axes, you need a minimum of three accelerometers arranged in a triangle.

If the nunchuck has one less accelerometer than the Wii remote, I would therefore imagine that it has two. This will allow it to detect translation and some rotations, but there will be ways in which it can be rotated that the accelerometers are not able to detect. Given the size and shape of the nunchuck, I wouldn't be at all surprised to find that it has an accelometer roughly under the stick and another close to where the cord comes out, although I haven't (yet) opened up one of my nunchucks to verify that this is in fact the case.

The accelerometers used in the Wii are pretty neat little devices. You can see their datasheet here. They're built on silicon MEMS technology with an integrated CMOS driver circuit in the package. It's a nice application of MEMS (micro electromechanical systems), which up until now hasn't seen many consumer applications beyond airbag sensors (which are another type of accelerometer) and shutters for DLP projectors.