ThinkGeek sound project

This past weekend, I followed Alex Kung's tutorial for combining a ThinkGeek Personal Soundtrack Shirt and a 12-channel remote into a budget sound system for R2. A CF-III system (click here for a link to the commercial module and here for a link to an R2 builder's tutorial showing how to combine it with a remote) would be nice and appears to be getting to be fairly common in the R2-D2 Builders Club, but I wanted to first put a project such as this together and second save on the cost of a high-end system. CF-III or its successor will go into the someday/maybe heading of my to-do list.

Chris James, of the R2 Builder's Group, has posted some advanced ideas about the CF-III system.

Back to my own ThinkGeek sound system project.

Upsides

• Easy to put together.
• Pretty cheap (about $20 for the T-shirt, down from $40, I think, and another $25 or so for the remote, plus miscellaneous wires, connectors and so forth).
• Uses mp3 sound files and a card, which makes changing the sounds easy.

Downsides

• The provided speaker isn't very loud.
• The single-remote setup allows only 10 R2 sounds.
• As Alex points out in his tutorial, there is a slight delay between pressing a button on the remote and hearing the sound.
• The remote receiver assembly uses relays to close and open circuits, and each click is audible and distracting, at least without an enclosure
  

Alex's tutorial explains the nuts and bolts. His idea of using a lighting circuit to demonstrate the remote was good. I used an LED instead of a lamp.

Off:


And on:

I also checked the remote receiver's relay using a multimeter.

A measurement of infinite resistance:



and one of little resistance once the relay closed the circuit:




This was the arrangement after I finished putting together the wires. I also replaced the ThinkGeek speaker with a 75-cent 8-ohm speaker from AllElectronics and thought the volume was better.




Next steps

• I stripped far too much insulation off the wires I connected to the remote receiver's terminal blocks and am concerned about the possibility of exposed leads touching; I'll cut and strip new wires.
• I'll put the arrangement into an enclosure.
• Fairly soon, I'll need to decide on batteries for the droid and settle on a power system. The remote receiver uses 12 volts for the relays. The ThinkGeek part of the sound system is set up with four AAA batteries, which I'll want to replace.