PIC18F4550 has a USB Interface easy to use, code or configure. This page will help in trying out this PC friendly PIC Microcontroller. A useful HowTo by Dan Overholt. of OverTone Labs- CUI32Stem
The CREATE USB Interface
All pre-made CUI boards are black as shown, with the new PIC18F4553 that has an increased resolution 12-bit ADC! They also natively support Open Sound Control (OSC) and MIDI-over-USB functionality in addition to the default HID firmware
The CUI also now speaks MIDI-over-USB natively, this bypasses the old-skool MIDI baud-rate limit of 31.25KHz, since the concept of buad rate is completely obfuscated with MIDI-over-USB. Additionally, this firmware (for the 18F4553-based CUIs) sends all the analog input pins as pitch-bend type data (using all 12 bits of the ADC converter) along side note-on/note-off data from the digital input pins.
The PIC is the heart of the board. It's a programmable microcontroller with 32Kbytes of flash program memory and 2kbytes of general purpose SRAM. It has 13 A/D inputs and 18 general purpose I/O ports. On the CUI board, one of the general purpose I/O pins is dedicated to the "program" button to enter bootloading mode. You can use the remaining ports for anything you wish.