There was one complication, though: her motherboard doesn't have a COM-port on the backplate (since it's a 'legacy connector'...). The COM-port is a pinheader somewhere on the motherboard, so I had to think of something to hook it all up...
We started out with a half sphere made out of clear plastic. I'm guessing that it was meant as a basis for home-made christmas decoration or something like that...
We drilled 5 holes in it (4 for buttons and 1 for the cable to connect it to the PC), and we applied some sanding paper to the inside to give it a more diffused look:
Next, I made the painfully simple circuit. No active components, just a few wires and two LEDs (because I can't do any project without LEDs, right?):
So, what about making that COM-port externally available? I took a plate from one of the PCI expansion slots of the case, and grinded a slot in it:
Next, I took a tiny bit of stripboard and soldered a 7-pin header on one side...
...and 7 wires on the other side.
Then, a glob of hot glue secured the piece of stripboard to the plate. I made sure there was no short-circuit between the pins and the plate itself!
Here's a close-up of the pins sticking out of the plate.
All I had to do then is to solder contra-pins to fit in the pinheader on the motherboard, and to solder contra-pins for the pinheader on the expansion plate. I used UTP cable, because it has 8 wires and is really cheap and easy to work with. And I had some 80 meters of the stuff lying around. :)
The control in its natural habitat: klik's desk.
The two top buttons are for volume control, the red button on top is to pause/resume, and the bottom button is to skip to the next file in the playlist.
It has a blue power LED. When the port control is activated, this LED lights up. Note the subtle play of the shadows of the internal wires...
Pressing a button will light up a second LED, a red one. Visual feedback is nice.
It's been a fun project to do, especially the way I externalised the COM port. I also did that for babarage's winLirc receiver (she has the exact same motherboard).
I might want to do this more often, since PICs are really easy to hook up to a serial port!