A few weeks ago I made an instructable called "The zipper alarm". I integrated an Arduino in my pants so that an alarm would go off every time I left my zipper undone. Unfortunatly, there was a downside to this alarm: it only made one noise. BORING! That 's why I used my zipper-electronics knowledge to make a melody playing zipper.

A zipper synthesizer, our as I call it: THE ZIPPAPHONE!

Step 1: Parts

Arduino Uno,
a jacket with a metal zipper,
conductive sewing yarn,
normal sewing yarn,
press buttons,
plastic boxes for housing the electronics,

on/of tumble switch,
connecting push switch,
piezo speaker,
220 ohm resistors,
male header pins,
electric wire,
XLR wire,
XLR female and male connectors,
9 volt battery,
battery clip,
small nuts and bolts,
velcro.

Tools:

soldering iron,
hot glue gun,
sewing needle,
Maybe a Dremel.

Step 2: The Circuit

The circuit is inspired on the keyboard instrument you can build with the arduino starter kit. It's a very easy arduino project that uses a resistor ladder. This is a way to read a number of switches. The switches are connected to power through a resistor. When you press each button, a different voltage level will pass to the input pin of the Arduino and the Arduino translates this value in a tone.

I made a double resistor ladder because I wanted the jacket to play 8 notes. When I made a 8-step resistor ladder the voltage difference between the last 2 switches was to low to get a good reading. The instrument kept on playing the wrong notes... And that is something only the musician is allowed to do!

I wanted to play a specific song on the jacket so the notes I programmed in the arduino are the 8 notes I needed for that song. The frequencies of the notes I found here.

Step 3: Making It Happen

Translating the circuit into something you can put in a jacket was a different thing. The electronics have to be removable so the vest can be washed. Musicians sweat a lot under the hot stage lights, especially when they are wearing a jacket!

I've put all electronics in black plastic casings and they connect to the jacket with press buttons. The buttons also conduct the electric current to all the different components. The buttons are sewed to the boxes and I used some hot glue to fix them firmly because any movement would damage the soldering. The resistor ladders are in the two little black boxes on the right (in the last picture). The arduino is in the bigger one on the left. The little one on the left holds the button and the piezo speaker.

All connections between the boxes are made with conductive sewing yarn except for the piezo speaker in the little box and the XLR cable. I use an XLR cable because the XLR connectors snap together, making it a reliable connection and because a XLR cable has 3 wires. I needed 3 wires. Two signal wires (to A0 and A1 of the Arduino) and one ground wire.

In the two sketches I tried to draw the arrangement of the resistors, the boxes, the switches and the stitches. More about the sewing in the next step.

Step 4: The Sewing

And then there was some sewing. O boy, did I sew!

Every position of the two resistor ladders had to connected to the right "switch". These "switches" are 8 steps on the zipper. In each step I made both sides of the zipper conductive with the yarn. I soldered a little piece of metal on the zipperhead (I don't think this the right name... does it have a name? If it doesn't, "zipperhead" it shall be!). So when the zipper passes a position both sides of the zipper are connected (by the piece of metal) and the switch is closed. Than the Arduino plays the note dedicated to that position of the zipper.

Be careful when soldering the little connecting piece of metal to the zipperhead (I'm really digging this word), mask the zipper and the fabric of the vest with some tape. I also made the surface a little more rough with my Dremel to make sure that the solder would stick.

Step 5: Play That Funky Music!

When all the sewing is done, the boxes are connected to the jacket with the press buttons (and a little duct tap, to be sure) and you are ready to play! The Zippaphone is played by sliding the zipper up and down and pressing the switch on the little box when the zipper is in the right position. The current only flows when this switch is pushed, because otherwise every single note would be played when the zipper slides up or down. By pressing the button at the right time you play the right note... almost every time.

Hey, it 's not a professional instrument but I had a lot of fun playing around and making this racket jacket!

At the end of the video you can see me playing a song on the Zippaphone.