Parts

First up, you'll need an Arduino Micro. If you can get one without headers that's great but as of this writing they're only available with headers. So we'll just clip them off.

You'll also need a MiniDIN-5 connector for the keyboard. We used this one from DigiKey

A Micro-USB cable connects from the Micro to your computer

Finally, this lovely Altoids tin will do a great job of holding it all

Tools!

You'll also want a soldering iron, solder, wire strippers, a rotary tool (to cut into the tin) and maybe some double-sided foam tape.