If you’re in high school education, there’s a good chance that your school uses ‘interactive whiteboards’, the surface that the computer image is projected onto then you can use a pen to play word matching up games or draw pictures, in effect control the computer.

Considering I have a projector, I have always been fond of this idea, however I don’t have the money to install a proper interactive whiteboard, and even if I did save up it’d be a bit pointless, it’d be for show more than actual use, once the ‘coolness‘ had worn off. This led me on to think “can I have an interactive whiteboard without the surface?”, of course I did some research, and came across eBeam Projection – which, yeah, it looks cool, but it’s also expensive. I then thought “can I make my own interactive whiteboard?”…

The answer is, yes I can! (and of course I have). I’m writing this less than 24 hours into the project, so at the moment my interactive board isn’t as good as one of the commercial ones. Nevertheless, it works! Let me explain how it works; my Optoma EP721 DLP projector has a Logitech EyeToy webcam next to it, these are both connected to a computer. I then have a program that detects light objects and can manipulate the location of these into mouse movements, therefore allowing me to shine a laser beam at the board and that be reflected in the movement of the mouse pointer. I can also use a torch as a pen against the wall to move the mouse. Two issues I have with this; number one is that the webcam is too far back and picks up more than just the projected image (and I can’t move it forward because it’ll interfere with the projected image and theres nowhere to mount it) rendering it out of calibration, a theoretical workaround for this is to have a piece of software to zoom in so it picks up only the projected image then relay the zoomed image to the light detection application – I say theoretical because it didn’t work when I tried it, which leads me on to the next issue. It only works on black, in respect to the first issue, it thinks the mouse pointer is a light object and creates a movement loop only ending up in the mouse ending in a corner. Any other colour, such as the desktop, also doesn’t work because the program cannot distinguish between the desktop image and the laser dot or torch light – so because of this I’ve wrote two programs (sorry, I’m not releasing them), one called “The Green Dot” (see video below) and another called “Flipchart”, the former basically being a dot that moves around the screen controlled by the mouse and the latter a simple drawing program, but you don’t have to click to draw, so you just point the laser at the board and it draws, but of course as I mentioned calibration needs some work so its not excellent.

Here’s a video I uploaded to YouTube demonstrating “The Green Dot”.

That’s all for now!