work and ideas by Jochen Zaunert  
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Wii Whiteboard

This Project is based on Johnny Chung Lee's idea to bulit a lowcost whiteboard with Nintendo's Wii Remote Controller (link).

I tried out his Software and all works very nice. Except two things:

  1. For some unknown reason, it's impossible to use the pencil or highlighter function that comes with Microsoft PowerPoint (2003 and upwards)
  2. Only the left mouse button is used. (But the Wii remote can track up to 4 points at a time - why don't implementate also the right mouse button...

Unfortunaltely, I have less knowledge in programming, so I decided to use GlovePie (link) as a simple scripting language for my work. The good thing is, that it is way more easier to recive and process data that comes from the Wii remote.

Here is what I've done so far:


And here you can download my script and the calibration image I used in the video.

Download Wii-Whiteboard GloovePie script

Callibation Image

And now for the bad news:
My script works fine, if the IR-Light pen is close to the Wii remote. But if you're using it with a beamer and with a longer distance between the IR-pencil and the Wii remote, there is no more recognition. This seems to look like that I've used IR-Leds that are to weak. But: When I'm using Johnny's software with exactly the same placement and IR-pencil, it will be recognized...I'm totally confused about this...
I also knew about the fact that is impossible to draw a stright line in Microsofts PowerPoint. But this not a problem for me now. I'd rather want fix the problem with the distance... -- Meybe someone else has an idea...

Some words to the tecnical backgound:
It's a very easy script except the calibration. Main part is: if the Wii remote detects a IR-dot, the mousepointer will be set to this point and the lleft-mouse-button will set to"hold down" as long as the IR-dot will be visible.

To get to right screen position it is necessary to transform the wii-coordinates to the screen coordinates. The formulas for this operation are:

where a1, a2, a3, b1, b2, b3, c1, c2 are unknown parameters. To get these you will need to do the 4-point-calibration.

With 4 Points (both x and y) on 4 known positions on the screen you'll get 8 equations with 8 unknowns. So I have to solve a 8x8 matrix. Unfortunately I think GloovPie cannot handle arrays. So I have to solve it manually... (Anybody who can do this in a better way within GloovePie? -- cause I feel ashamed to do this like a child...)

Need help?
Yes definitely, I need help. I would like to get this script working with a beamer... cause this is the main thing I want. The are so many ideas what I can do furthermore, if you think that you can track up to 4 points at a time... If you look closely at my script you'll see that I started with some first steps to get a cool multiouch interface for Google Earth... Zooming for now and maybe later also rotating...
With GloovePie it is so simple to add these features but if this scipt won't work with longer distances like Johnny's software its less worth...

So feel free to play with my script - maybe you got some ideas... you can contact me by mail

j g z 7 (at) g m x . n e t

    Below, there is another Video showing, what I've done during a project at my university: (2008, Jochen Zaunert)