I picked up the ukulele so that I could play snow-themed Christmas songs on a Hawaiian instrument, cuz I like congruity. And sarcasm. Of course, then the whole 'making' thing spread through my life and wouldn't leave my uke alone! In this Instructable, I'll show you how I hooked my acoustic ukulele up to my computer using a MaKey MaKey and used it to control dancing characters in Scratch.
Step 1: Materials
If you haven't played around with a MaKey MaKey before, you're missing out; they're great for user interface tinkering, especially for kids. It's a little microcontroller that emulates your computer keyboard, sending out keystrokes to the computer when a circuit is completed on one of its inputs.
The MaKey MaKey doesn't require Arduino knowledge, but you can use the Arduino IDE to reprogram the keystrokes (and other things) if you want. You can do a project like this with a number of other Arduino-compatible boards (Leonardo, Micro, Due, Trinket, etc - but not Uno, alas) that are able to use the mouse and keyboard libraries.
- Your body
- MaKey MaKey (and associated usb cord) - photo from the MaKey MaKey website
- Computer (with Scratch or your choice of interactive software)
- Ukulele (or another instrument for hacking)
- Copper tape
- Alligator cables
- Paper tape/Masking tape
- Metal Bracelet, Foil, or Wire
Step 2: Preparing the Ukulele
My ukulele has metal (but not reliably conductive) frets, and nylon strings. If your instrument has metal strings, this project is an entirely different proposition, but worth experimentation.
I used copper tape to cover the frets (as I said, they didn't conduct very well on their own), pressed it down as much as possible to keep it from buzzing the strings, and ran the connection to the back of the neck. The first four frets are the only ones I use with much frequency, so I only did those.
Starting with the first fret, cut a piece of copper tape that will go all the way across the fret and around the top side to the back of the neck. My personal experience with copper tape (YMMV) has shown that it conducts most reliably along a single side, so you'll see that all of the connections I make between different pieces of tape have a little flap folded over to provide that direct connection between front and front. Another piece of copper tape then runs from the back of the neck near the fret, down to near the body. Here you fold it over and make another flap, where the alligator clip will attach. You could also use a single, longer piece of copper tape.
To protect this copper tape from making accidental connections with others, or your hand, cover it with a layer of paper tape or any other non-conductive adhesive material. I like paper tape or painters tape because it doesn't do damage to the surface of the instrument and comes off cleanly.
Repeat for the other frets. Use tape to keep them isolated.
Step 3: Connecting to the MaKey MaKey
Clip an alligator cable to each of the copper tape flaps you've made and attach the other end to one of the inputs on the MaKey MaKey (any but 'Earth'). Keep track of which goes with which fret; you'll need to tell Scratch what to do with each of those keystrokes.
The MaKey MaKey can be attached to the back of the ukulele (with tape in my case - again, I didn't want to attach it permanently or damage the body), or put in your pocket, or strapped to a lazy dog. It just needs to be close enough to attach to the uke and your body.
Step 4: Your Conductive Body
Your body is part of the circuit, or didn't I mention? You'll connect an Earth/Ground spot on the MaKey MaKey board to your body via a metal bracelet (or ring of wire) on the end of an alligator cable. Put on the bracelet, make sure everything is plugged in and turned on, and when your left hand touches the frets, you'll complete a circuit that runs through your body and the MaKey MaKey will send keystrokes to your computer.
Step 5: Coding
I created a program in Scratch that changed the "costumes" on a couple of different sprites. In this instance, the different "costumes" were simply different body positions, so changing them made them appear to dance.
I also used recordings of them laughing that were triggered by some of the same key commands. You can make them do many things at the same time if you use the same key inputs.
(The two dancing characters are directors at Maker Education Initiative, Lisa Regalla and Steve Davee, who I met through the Maker Corps program. They're amazing people, and it wasn't hard to find clips of them laughing.)
Step 6: Fin
Enjoy! Try different instruments! Many musical instruments are made of metal or have various metal bits What could you connect on other instruments, especially those that have different conductive parts to them?