I have posted a new version of WiimoteLib as a beta for people to play around with the Wii MotionPlus accessory.  Please note that this is not a stable release and should only be used if you wish to mess around with the MotionPlus.  Also note that only C# source code is included in this release as it is not a final build.  Here’s the change log:

v1.8.0.0

• Taiko Drum Master’s TaTaCon drum controller supported (Dean Herbert)
• Bare-bones Wii MotionPlus support (wiibrew.org, testing by Tyler Tolley)
• WiimoteTest UI changed to add MotionPlus data
  • Please note that the current version is VERY flakey and may not work at all for you.
  • Pair your Wiimote, plug in your MotionPlus, call InitializeMotionPlus()
  • Extensions plugged into the MotionPlus will give wacky results…not supported…yet!
  • Internal changes to perhaps fix some threading issues

So remember, it’s a beta, it may not work for you, and the data you’ll get back from the accessory is just the raw data it provides.  You won’t get real orientation values.

That said, head over to CodePlex and give it a try! (Brian Peek)

Great work Brian!

He states that the changes for this release are as follows:

• Writing registers is now properly waiting for the Wiimote to reply before continuing…this removes all of the Thread.Sleep() calls and should *greatly* improve performance when setting LEDs and rumble (Serial Nightmare & wwibrew.org)
• Guitar Hero: World Tour Guitar and Drums now properly recognized and used (wiibrew.org, tested by Tyler Tolley and Mauro Milazzo)
• Guitar whammy bar is now a 5-bit value instead of 4 (wiibrew.org)
• Position of 4 IRs now properly reported in Basic reporting mode (Dan Carter)
• Found1/2 now properly reported in MSRS (reported by akka243)
• MSRS project updated to Microsoft Robotics Developer Studio 2008

Brian Peek has released a new project over at the Coding4Fun site, that utilizes my balance board code (cool) the following has been taken from his site:

I previously talked about my WiiEarthVR project shown at PDC project, and now I have posted the article for the application up at the Coding4Fun site.  Full source code is available.  You’ll need some hardware to make this go, namely a Wiimote, Nunchuk, Wii Fit Balance Board and a pair of Vuzix VR920 glasses, but the hardware can be toggled on or off depending on your own setup.  The VR920 glasses are pretty cool in that they also work with a variety of FPS games on your PC with a custom driver they include.

The article will, among other things, teach you how to use Virtual Earth 3D from a managed host (i.e. a WinForms app, not a web page), how to talk to the Wiimote, Nunchuk and Wii Fit Balance Board, how to retrieve the head tracking data from the VR920 glasses from .NET, and how to draw stereoscopic 3D images to the VR920 glasses from .NET.  Quite a bit packed in there…

Anyway, have a read and, as always, questions and comments are welcome.

Open up Datatypes.cs and add the following to public struct BalanceBoardState:

/// <summary>
/// The Balance Boards center of gravity
/// </summary>
public BalanceBoardCOG CenterOfGravity;

Next add a new struct to Datatypes.cs to contain the COG X and Y values, like so:

/// <summary>
/// The Balance Boards center of gravity (float values)
/// </summary>
public struct BalanceBoardCOG
{
/// <summary>
/// Balance Board center of gravity X value
/// </summary>
public float X;
/// <summary>
/// Balance Board center of gravity Y value
/// </summary>
public float Y;
/// <summary>
/// Balance Board center of gravity point value
/// </summary>
public PointF COG;
}

Next add the following variable definitions above the default constructor within Wiimote.cs:

// length between board sensors
private const int BSL = 43;

// width between board sensors
private const int BSW = 24;

BSL is board sensor length and BSW is board sensor width. These points were obtained via measuring the distances between the centers of the boards feet. I am not brave enough to open my board up to get the exact values but these seem to work fine for me.

Finally add the following chunck of code to the BalanceBoard case of ParseExtension:

float Kx = (mWiimoteState.BalanceBoardState.SensorValuesKg.TopLeft + mWiimoteState.BalanceBoardState.SensorValuesKg.BottomLeft) / (mWiimoteState.BalanceBoardState.SensorValuesKg.TopRight + mWiimoteState.BalanceBoardState.SensorValuesKg.BottomRight);
float Ky = (mWiimoteState.BalanceBoardState.SensorValuesKg.TopLeft + mWiimoteState.BalanceBoardState.SensorValuesKg.TopRight) / (mWiimoteState.BalanceBoardState.SensorValuesKg.BottomRight + mWiimoteState.BalanceBoardState.SensorValuesKg.BottomLeft);
//
mWiimoteState.BalanceBoardState.CenterOfGravity.X = ((float)(Kx – 1) / (float)(Kx + 1)) * (float)(-BSL / 2);
mWiimoteState.BalanceBoardState.CenterOfGravity.Y = ((float)(Ky – 1) / (float)(Ky + 1)) * (float)(-BSW / 2);
//
mWiimoteState.BalanceBoardState.CenterOfGravity.COG.X = mWiimoteState.BalanceBoardState.CenterOfGravity.X;
mWiimoteState.BalanceBoardState.CenterOfGravity.COG.Y = mWiimoteState.BalanceBoardState.CenterOfGravity.Y;

This calculates the COG using moments. The values can then be obtained via the following calls:

X = ws.BalanceBoardState.CenterOfGravity.X.ToString();
Y = ws.BalanceBoardState.CenterOfGravity.Y.ToString();

COG (as floating point) = ws.BalanceBoardState.CenterOfGravity.COG.ToString();

Using COG your board can easily be adapted for use as a joystick. The X and Y values can also easily be plotted for a visual representation if required.

/// <summary>
/// Stones per sensor
/// </summary>
public BalanceBoardSensorsF SensorValuesSt;

and

/// <summary>
/// Total stones on the Balance Board
/// </summary>
public float WeightSt;

Next open up Wiimote.cs and add the following variable above the default constructor just below the Kg – Lb vars:

// kilograms to stones
private const float KG2ST = 6.35029318f;

Next we are going to add the code that populates these definitions/variables

Still within Wiimote.cs add the following code to the BalanceBoard case of the ParseExtension function just below the Kg – Lb equivalent code:

mWiimoteState.BalanceBoardState.SensorValuesSt.TopLeft = (mWiimoteState.BalanceBoardState.SensorValuesKg.TopLeft / KG2ST);
mWiimoteState.BalanceBoardState.SensorValuesSt.TopRight = (mWiimoteState.BalanceBoardState.SensorValuesKg.TopRight / KG2ST);
mWiimoteState.BalanceBoardState.SensorValuesSt.BottomLeft = (mWiimoteState.BalanceBoardState.SensorValuesKg.BottomLeft / KG2ST);
mWiimoteState.BalanceBoardState.SensorValuesSt.BottomRight = (mWiimoteState.BalanceBoardState.SensorValuesKg.BottomRight / KG2ST);

The above block of code enables calls to be made to obtain values for each of the four sensors in exactly the same way as you would for Kg’s and Lb’s e.g.

TopLeftInStones = ws.BalanceBoardState.SensorValuesSt.TopLeft;

Finally for total weight in stones add the following line below the equivalent Kg / Lb definitions:

mWiimoteState.BalanceBoardState.WeightSt = (mWiimoteState.BalanceBoardState.SensorValuesSt.TopLeft + mWiimoteState.BalanceBoardState.SensorValuesSt.TopRight + mWiimoteState.BalanceBoardState.SensorValuesSt.BottomLeft + mWiimoteState.BalanceBoardState.SensorValuesSt.BottomRight) / 4.0f;

And there you have it your balance board will now cater for the UK Stones measure and calls can be made using equivalent code to that provided for Kg’s and Lb’s.

In an effort to put out more frequent builds with fewer changes, Brian peek has released WiimoteLib v1.4 to CodePlex. This release contains the single most requested feature: multiple Wiimote support.

The original Coding4Fun article has also been updated with some details on how to use multiple Wiimotes, as has the WiimoteTest application included with the distribution.

Changes

• Multiple Wiimotes supported!
• Slight change to ExtensionType enum for better extension detection
• Decided I didn’t like the dependency on System.Drawing for the 2D point so am now using my own Point structs. Sorry…
• WiimoteTest app updated to show multiple Wiimotes working

SOURCE: Brian Peek