So, probably just like many of you guys, some years ago I found Johnny Chung Lee's wiimote whiteboard project (http://johnnylee.net/projects/wii/) and decided to give it a try.

Since I couldn't find any IR pens provider in my country and also since I'm really cheap, I decided to build my own. I googled around and found several instructables on this topic and most of them work just fine. The problem appeared when an Italian teaching school saw my whiteboard and wanted to buy the system from me, since my original pen didn't look profesional at all. I went back to the internet to find a better deal, but I couldn't, there are no functional good looking DIY IR pens out there...

So I decided to design my own, took me a while to find the perfect chasis for it, I tried with markers, highlighters, pens, etc. but then a friend of mine gave me her empty pencil leads box and it was perfect... I'm from Argentia, so I dont know if you'll find these very same box in your country, but you'll probably find something similar. This is the one I used: http://www.sabonisweb.com/ListaProductos.aspx?tipo...

I've been talking a lot now, but I haven't explained yet what IR pens actually are. An IR pen is an electronic device used for multiple interactive whiteboard systems, it consists of a cell, a push button and an IR LED. Buying one can be quite expensive considering the materials are actually realy cheap.

That's it for our intro, let's get working...

Step 1: You'll Need...

Bill of materials:

1 x IR LED

1 x Push to make button

2 x button cells (I took mine from a 12v battery, that way is much cheaper, check this out: http://mods-n-hacks.wonderhowto.com/how-to/hack-12...)

1 x Pencil leads case, I used this one:

http://www.sabonisweb.com/ListaProductos.aspx?tipo...

Some single filament wire....

Tools:

Soldering Iron

Soldering Wire

Pliers

A swiss army knife, or an exacto knife, or a kitchen knife or a sharp rock, whatever rows your boat...

Step 2: Preparing the Leads Case

Unassemble the case and separate

Take your knife and cut the holes seen in the picture, you got to be careful and cut the push button hole in the exact position, so it'll still be pushable when the white thingy is on...

put the button cells, the push button and the white thingy inside the big white thingy and check if you can push the button by clicking on the white thingy...

Step 3: Electronics

Next step is the electronics, you may find it weird that the cells are connected in parallel in the schematic, that's just so it'll last longer...

There's actually not much to say about this, it's a fairly simple circuit. Use your solder iron and the soldering wire to solder the components and the wires...

Step 4: Put It All Toghether

Yes, by putting all "toghether" I just mean puting the top on... and voilá! it's done... congratulations!
To check if it works, you can use any digital camera (even your phone's) just point to it and click....

If you don't want people to know it's a pencil leads case... you can use polish remover to fix that... If you do so, you'll end up with a nice transparent top and you can print your own design to put behind that...

That's it guys, hope you enjoyed it... if you make it, or something similar, leave a picture in the comments...