Thanks for letting me show my MIDI controller toy project [show-and-tell] it turned out to be a really good show! Here is a little more information about the project:
I acquired a cool used toy from my local Salvation Army some time ago for a whopping $1.95, and knew it would be a fun toy to hack. In the past I’ve experimented with using circuit bending to hack toys to make goofy noises, but this time I wanted to try to make something more useful, like a MIDI controller. In other projects I’ve used the Teensy series of microcontrollers from PJRC to mimic USB devices, and realized it could be really useful in this project. It’s cheap, powerful, small and includes native USB HID functionality, and can be used with the Arduino IDE, so it seemed like the perfect solution for me. I was able to hack together this project in a couple of days, thanks to some really helpful generalized debouncing code that Limor posted back in 2009.
This is also my first attempt at creating an Instructable, so I have tons of pictures, documentation, source code and advice about how to turn almost any rescued toy into a MIDI controller. Hopefully it will help a few of your readers create their own cheap MIDI controllers