MIDI Keyboard Controller, Part 4

So, I was supposed to be continuing on with the MIDI keyboard, but I've had to press the big red button. Turns out I want this to be a USB keyboard now (still MIDI, but plug right into the PC). So that means a new microcontroller, somewhat new layout, using USB power, and a bunch of firmware redesign. I'm going to do a PCB spin this time around to hopefully speed up prototyping. Now its the USB-MIDI Keyboard Controller!