Picture of Converting a rescued toy into a MIDI controller
In this Instructable, I will walk you through the process of converting a rescued noise-making children's toy into an actually useful musical instrument using MIDI! Take a moment to just glance over the titles of the steps in this Instructable and familiarize yourself with the general process, so you know what to expect when you're complete, and whether or not this Instructable is what you're looking for.

I'll help you pick out a good toy to rescue, and then guide you through the process I used to successfully hack all of the buttons and switches to make something really cool and useful. We'll rip out the old, useless guts of the toy and replace it with a cheap microcontroller that is capable of sending and receiving MIDI messages to a PC, which will do the actual sound synthesis for us. I'll discuss the ins and outs of how to do this using code, and hopefully help you improve your project-making skills along the way!

Example of finished MIDI controller

What is a MIDI controller?
The Musical Instrument Digital Interface (MIDI) protocol was developed by professional audio technicians as a way for their various electronic devices (drum machines, synthesizers, samplers and more) to communicate by sending messages back and forth. Messages like, “play this musical note” and “we’re now in the 3rd beat of the 2nd measure” are transmitted between devices to help keep all of the devices in sync and reduce the amount of work that people need to do.

Every musical device out there today can be classified as a specific type of device, such as a sequencer, synthesizer, sampler, controller or others. In this article, we will be converting a toy into a MIDI controller. A MIDI controller typically has no ability to produce any noise or manage musical notes into a piece of a music. Instead, it’s more like a keyboard or a mouse; they tell a more intelligent device about changes in it’s own systems (i.e. “user pressed the A button”).

You can learn a great deal more about the MIDI using a variety of resources. Since MIDI has been around for quite some time, there is a great deal of information available on the internet, such as:

For personal reference, I ordered the following book and have been very happy with it: http://www.amazon.com/MIDI-Power-Comprehensive-Robert-Guerin/dp/1598630849/

KoreusZ1 year ago
I have an old toy guitar, similar to the one you used. I better get started. :)
Dlowe0892 years ago
This is incredible. Now putting on my to do list.
I'm surprised no one has commented! This is the most informative guide on MIDI I've seen here! Especially when it comes to MIDI-fying an instrument...
Definitely one to favorite and save!

Thank you for writing this up!
Keep up the good work and happy making!