Help with traditional midi to usb-midi using arduino!

Hello!
I have an old keyboard that uses the old fashioned midi DIN connector and I don't have a midi to usb adapter, but I know that the same can be done with an arduino UNO r3. Do anybody knows for a code that will read the incoming midi data (after making the proper hardware setup of course) and then mirror that data over the usb interface so I can later reprogram the 16u2 chip to act as a native midi device?

Thanks in advance!

Bump!