MET:Wiimote Whiteboard
Wiimote Interactive Whiteboards are Human-Computer Interface devices developed in 2007 [1] by electrical and computer engineer and inventor, Johnny Chung Lee, as a low cost alternative to other commonly available, but relatively expensive, commercial interactive technologies such as the SMARTboard, Mimio and other similar devices. The key difference in Lee's design over commercial units is that it utilizes the infra-red (IR) camera in a Nintendo Wii remote to track movements of an IR-source as an input device for the computer. Alternatively the basic design of most other IWBs takes advantage of physical or electrical contact between a screen and a special pen, or even the user's finger, as the input device.
How Interactive White Boards Work
IWBs are typically composed of five basic elements: a computing device, a digital projector, an interactive display screen, a pen, and software to make it all communicate. These elements are connected in such a way that the digital projector displays an image of the computing device's screen on the interactive display and the pen is used to add digital "ink" and to control the computer in much the same way as a traditional mouse and keyboard do. This is done by touching the interactive display with the pen or a finger to select features and functions made possible by software that then communications the input to the computer that responds accordingly and such that the projector displays the digital ink or the appropriate result of the interaction that occurred.
The Wiimote Interactive Whiteboard functions somewhat differently than typical IWBs in that there is no interactive board for the the pen to interact and communicate with. Rather, a blank screen or wall is used to project the computer images on, and the pen interacts with with a Nintendo Wiimote which then communicates with the computer via Bluetooth. The pens used with the wiimote are equipped with an IR source at the tip and button to turn the source on and off. Turning on the IR source is then equivalent to touching the screen with traditional IWBs. The wiimote contains an IR camera that is able to sense the position of the IR source. Using location and tracking software, the location of the pen can be tracked and communicated to the computer after a simple calibration procedure is performed.
Hardware
Computing Device and Projector
Hardware requirements for the Wiimote interactive Whiteboard have few limitations. The computing device simply needs to be capable of running the calibration and interaction software (ie. is sufficient to run Mac OS X, Windows Vista or Windows XP) and the projector must connect to the computing device.
Nintendo Wiimote Controller
The Nintendo Wiimote controller is recommended for use in Wiimote Interactive Whiteboards. In discussion forums[2], generic Wiimote controllers have been described as having inferior performance and range of use.
IR Pen
A large variety of IR Pens are available for purchase online and instructions for homemade pens are just as common[3][4]. These include varieties that are pressure sensitive in the tip or that have a button on the side that is pressed to activate the IR source. The recommended IR source is the Vishay TSAL 6400 IR LED that emits at 940 nm [1]
Bluetooth Dongle
The Wiimote communicates via the Bluetooth short range wireless connectivity standard (IEEE standard 802.11.15.x), thus the computing device for a Wiimote Interactive Whiteboard must also be able to communicate using this standard. Many desktop and notebook computers are sold with this capability, but Bluetooth capability can be added to a device using a Universal Serial Bus (USB) Bluetooth adaptor or "dongle".
Software
IWB software is available from a variety of open source and commercial providers. Basic interactive software functions usually include an option to display a keyboard on screen for typing; digital ink pens, paint brushes and highlighters for marking up displayed images and text; as well as screen or video capture to record work that has been done on the IWB. More advanced functions include interactive games, learning modules and templates that can be adapted for individual use.
- Wiimote Whiteboard, by Johnny Lee
- Smoothboard, by Goh Boon Jin
In addition to this interactive software, the Wiimote Interactive Whiteboard requires software for the computer to communicate via bluetooth with the wiimote. This too, is available online as open source software.
Depending on the provider, both the interactive software and Bluetooth calibration software is minimally available for Windows and Mac OS X, and may be available for Linux.
- Wiimote Whiteboard, by Uwe Schmidt
Affordances
The primary affordance of the Wiimote Interactive Whiteboard is its affordability over commercial devices with starting prices of approximately $800 not including the computing device or projector. It is only recently that these prices have dropped even this low, as they were well over $1000.
A Wiimote controller retails for $40 (online for as little as $10), and pre-made IR-pens can be purchased online for $15 to $30. The materials to build an IR-pen cost approximately $5 for the IR-LED, dry cell, resistor, and wire. Bluetooth dongles cost approximately $5. Thus it is possible to assemble a Wiimote Interactive Whiteboard for $15 to $70 dollars, depending on needs, quality of materials and skills with basic wiring.
The portability of the Wiimote Interactive Whiteboard is another pertinent affordance. Unlike many commercial devices that are dependant on the often large display screen as an integral part of the system, the Wiimote does not require any screen more significant than a blank wall. This makes the system easy to transport. Furthermore, the design also allows for rear-projection on a translucent screen. This eliminates shadows caused by the user blocking the path between the projector and screen and between the IR-source and Wiimote.
Additionally, the Wiimote is able to track up to four IR-sources, thus making it possible for the Wiimote Interactive Whiteboard to function as Interactive Multitouch Displays do. Such devices are able to incorporate interactions multi-touch gestures such as the pinch and swipe motions made popular on iOS devices. This allows a greater range of interaction with software such as GoogleEarth, SketchUp, EduSim3D and Kindlelab.
As an educational device, the affordances of IWBs are well documented; however, the Wiimote IWB's simplicity in design allows for it to be a meaningful engineering and design project in itself at many levels. Students may benefit from educational activities designed around constructing IR-pens from a variety of materials, physically setting up and troubleshooting the device in various configurations and designing or improving the code for programming them.
Constraints
The Wiimote's 45-degree field of view is a major limiting factor in setting up a Wiimote Interactive Whiteboard. As a result, positioning the Wiimote such that it has an unobstructed view of the the display can be challenging. This is evidenced by the multitude of forum posts and YouTube videos describing this challenge and potential solutions. Some of these solutions include:
- using multiple Wiimotes to cover the entire display area
- increasing the distance between the Wiimote and the display
- mounting the Wiimote on the projector, and
- ceiling-mounting the Wiimote.
Each of these solutions has trade-offs with further constraints. When using multiple Wiimotes, it becomes increasingly difficult to correctly calibrate each Wiimote which results in erratic behaviour in tracking the IR-source. Increasing the distance between the Wiimote and display decreases the resolution with which the IR-source can be tracked. This results in accuracy and precision errors when attempting to place the cursor or digital ink in a very specific location (as in clicking a button or connecting letters when writing). Nintendo claims that the Wiimote is accurate within five metres [5] of the IR-Source when used as designed; however, accurate and precise performance at such a distance when used as part of an IWB is debatable.
Unlike many popular commercially available IWBs, the Wiimote IWB is not touch sensitive and users accustomed to this feature may feel constrained by the requirement to use a IR-pen.
Because the Wiimote detects the four most intense IR sources at 940 nm, intense direct sunlight, candles and other heat sources may interfere with operation of the Wiimote IWB. However, sunlight interference is unlikely to occur, since it would also decrease the visibility of the images from the digital projector.
Notes
References
- Choulo, (2008, February 6). How to build an InfraRed pen [Video file]. Retrieved from: http://www.youtube.com/watch?v=I568NyZLJkY
- Lee, J, C., (2007, December 7). Low-cost multi-point interactive whiteboard using the wiimote [Video file]. Retrieved from: http://www.youtube.com/watch?v=5s5EvhHy7eQ&feature=player_embedded
- Lee, J. C., (2007) Low-cost multi-point interactive whiteboard using the wiimote. Retrieved from: http://johnnylee.net/projects/wii/
- Schmidt, U., (2008, February 8) Wiimote Whiteboard [Web log message]. Retrieved from: http://www.uweschmidt.org/wiimote-whiteboard
- Terracode, (2007). Homemade LED infrared pen for use with Wiimote projects. Retrieved from: http://www.terracode.com/IR_Pen/DIY_IR_Pen.html
- Nintendo, (n.d.). Tec spec . Retrieved from: http://www.nintendo.com/wii/what-is-wii/#/tech-specs