Musical Underwear is the underwear that gets down when you get down!
(Video is NSFW if your work frowns on undergarment flashing)
Step 1: Supplies
Also you'll need a pair of underwear, i chose some awesome looking ones from American Apparel.
And lastly you'll need a phototransistor that reacts to visible light a mini audio jack with free wires (not shown) and a 3 AA battery holder
Step 2: Picture Frame Circuit
Upon opening it up i discovered the "motion activation" was just a photoresistor, but it triggered the circuit when there was NO light, and i wanted the opposite. I had lots of ideas of building complicated transistor circuits to give a resistance when a phototransistor saw light. But i decided to try just to hook up the photo transistor as a direct replacement of the photoresistor and it worked! it reacted to the presence of light!
After figuring that out I removed the circuit from the plastic casing and desoldered the microphone, speaker, and photoresistor.
See the pictures for the taking apart process.
Step 3: Prepping the Circuit
Then i used a battery pack and soldered the circuit to that and make sure it worked. Once its working time to record your sound.
Step 4: Recording Your Sound
After some chatting with a friend with similar ideas in comedy, we decided that rickrolling someone when your pants come off was the best option.
First i edited the song "Never Gonna Give You Up" by rick astley down to about 10 seconds of sound using audacity.
To get the sound on the chip, I used the wires from the desoldered mic and hooked up with alligator clips a mini jack with some bare wire on one end and the plug on the other. I plugged it into my computer, held down the "record" button and pushed play on my computer.
The chip was soon filled with the sweet voice of Mr. Astley singing our favorite chorus.
Step 5: Embedding the Circuit Into the Underwear
Lastly I held everything down with hot glue.
Step 6: Finishing Touches
And that's it, you have a full set of musical underwear, you can even change the clip if you get bored with rick. I used a tab on the battery to prevent it from going off on its own.
Hope you enjoyed!