Recently I have had the fortune to experiment with two projects originally created by a professor at Carnegie Mellon University named Johnny Lee. A couple years ago he put together a few programs and some code libraries to form some of the most impressive pieces of software I have seen.
His research with the programs are focused on Human Computer Interaction (HCI) and repurposing a Wiimote and infrared LED’s (which act similar to the Wii-bar) to perform head tracking and to create interactive whiteboards. Instead of paying hundreds of dollars for the software and hardware inherent in these two systems, you can create either or both of them for around $50 thanks to the efforts of Dr. Lee.
Head Tracking
Head tracking is usually a luxury reserved for virtual reality researchers and high tech virtual meeting setups in corporate offices. It relies on finding the position of a single person relative to the screen and adjusting the screen contents to give the illusion of looking through a window into a 3-D environment. Traditional setups use sophisticated facial and head recognition software in order to locate the user in the room.
Because of the two dimensional nature of 99.999% of displays in the world, the head tracking induced 3-d effect only works for 1 person, the person whose head is being tracked. Everyone else in the room will not get the same effect.
I could go on to explain exactly how this system works, but Dr. Lee has been kind enough to post a video online explaining exactly what you need to know about how his software works, which is inserted at the start of this article.
Materials Required for Head Tracking
I’ll begin showing you how to create these projects by giving the materials list:
• A Windows computer* with Bluetooth and a monitor or projector
• One Wiimote
• One set of LED safety glasses
• Two Infrared LED’s
• Soldering gun and solder
• Necessary screwdrivers and or wire cutters needed for your particular set of safety glasses
• Wii head tracking software
*There are some hit and miss issues with Vista. When I did this project I used XP machines, your results may vary.
There is a chance that you will need to download and install the Microsoft Visual C# Express Edition in order to get the software to work properly. Also, Direct X is needed.
Creating head tracking hardware
Unfortunately the LED glasses I used for this project are discontinued and the link above in the materials section is for a different set. The basic principles are the same however.
Soldering:
For those of you who find soldering a challenge or have never had the chance to get your hands dirty fusing electronics together, here is a great piece by Instructables detailing what you have been missing out on.
You are going to need to open up the LED section of your glasses:
Carefully take note of how everything is wired, connected, and placed. If you need to draw a diagram to help then do so.
Snip off or de-solder the white LED and solder on the Infrared LED:
Then put everything back in its place and you are good to go:
One thing to keep in mind is this: now that you have infrared LED’s, you won’t be able to tell if they are on or not. A handy trick to tell is to use a cell phone camera on video mode and look at the glasses. Most digital cameras can see some of the infrared spectrum and it will be obvious that you have your lights on and are draining battery.
Now that you have the hardware, all you have to do is connect your Wiimote to your PC and run the software. But before you do that you really should read the readme file included in the zip you downloaded. It tells you that you need to edit a file by inputting the measurement of your screen in centimeters and editing a Boolean value to true or false depending on if your Wiimote is above or below your screen.
Hope you enjoyed this tutorial and will join us next week when we’ll show you how to build your own Interactive Whiteboard.
Here are some links that may prove useful: Johnny Lee’s Wiimote Project, Interactive Whiteboard FAQ, Head Tracking FAQ.
Tags: Head Tracking, Interactive Whiteboard, Modding, Wii
