After the success of the Clap-Off bra i got thinking about where the world of gimmick undergarments could go next. There are so many options from led bras to velcro boxers, but i wanted to do something a bit more musical. I came up with these as the men's answer to the clap off bra (but of course this method could be done with women's as well).

Musical Underwear is the underwear that gets down when you get down!

(Video is NSFW if your work frowns on undergarment flashing)

Musical Underwear from Greggawatt on Vimeo.

Step 1: Supplies

There was some thought going hhw to make my underwear sing. Of course the arduino was considered as a first option, but i felt that it was a little over kill for this project. I found at radio shack a talking picture frame that was motion activated. It could also hold a message that was up to 10 seconds in length.

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

My first step was to pull apart the picture frame and find out what i was dealing with. This is one of those "Push the button to record" picture frames, and it was triggered by motion.

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

Once you have the circuit out, its time to modify it for underwear use. First I extended both the speaker and phototransistor wire and soldered the photo transistor on.

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

Now what to play when one takes off their pants is very important decision. I had lots of ideas from medieval trumpets to car horns.

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

Now that it works time to get it on the underwear. I used some thick thread to sew the battery pack and the board to the back. I then ran the wire around the band and cut a small hole in the front to put out the speaker and the phototransistor.

Lastly I held everything down with hot glue.

Step 6: Finishing Touches

To hide the ugly speaker i made a cute bow for the front and hot glued that on.

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!