This build uses Synapse radio modules (2.4 GHz) for wireless communication; one in each Quiz Box and one connected to a PC via USB (for viewing/scoring). The PC program is written in Java, so could be run on any operating system, although, the serial USB connection is OS specific and I have only implemented it on Windows.
The build requires beginner to intermediate soldering skills. Also, you will have to send the electrical schematic files (that I have created) to a printed circuit board (PCB) manufacturer to be manufactured. In addition, you will need to be able to perform some drilling in the plastic quiz box. Also, if you want to add the acrylic LED shields, you will have to use a heat gun to bend them into shape.
The Bill Of Materials is attached below, and can also be found at: http://code.google.com/p/quiz-box (along with source code and other documents). You will need to download the BOM to get a list of the parts you will need, along with the suppliers.
Step 1: Soldering the PCB
On the download page in the google code site, I have placed a file, qb_docs_v2.zip. In that file there is another zip file containing the gerber files that a PCB manufacturer would need. You could use this, but it would be better if you learned how to generate your own, that way you could check it, add the order number, etc.
Once you have a PCB, you will find that it will require some soldering. There are two ribbon cable headers, two radio module headers and 4 resistors to solder in place. The resistor values are not very critical, I chose them to make a nice balance in the brightness of the LEDs, I might try to tweak them in the future to be a bit brighter and use more common resister values.
The radio module headers are the trickiest. They require care, because if done incorrectly, solder will wick up into the sockets and prevent the radio from being plugged in. If this happens, the best thing to do is to pull the plastic header part of with pliers, de-solder the pins, and try again with a new header. I've found that the best way to avoid this is to tape some masking tape over the open end of the header (see picture). Make sure that it goes as far back against the pins as possible, and use a small flat head screwdriver or similar tool to press the tape on. Then, put the header in the PCB and solder in place. Use a temperature controlled soldering iron and make sure that it is set at a low temperature (around 325 C works well for me). Try to apply the minimum amount of solder in order to get a good solder joint. Test fit the radio when done.
Update: I've found a better way to solder the radio headers. Just put the masking tape over the holes in the PCB, then poke holes in the tape with a pin (it may help to hold up to a light to see through the tape). Then score the tape along the holes with a knife. Finally, push the header into place, through the pin holes. After soldering, just pull the tape out from either end (it should break where it was scored).
The ribbon cable headers and resistors are easy in comparison. Just make sure the cable headers are straight. Bend the resistor wires as needed to fit them in.