If anything, pick up one of these:
http://www.newegg.com/Product/Product.a … 10213400:s

17 bucks. Can't go wrong.

I use this in my live setup. It's actually pretty cool. I built my self a VERY stripped down version of an Arduino Boy "locked" in mGB mode for it. Maybe I'll get a picture because I also added a "shelf" to the keyboard to velcro my Game Boy onto.

My ONLY complaint is that you can't change the MIDI output channel on the keyboard so it's always set to pulse channel 1 when I would much rather be playing an the wave channel for bass lines.

friendofmegaman wrote:

I'm just getting started with MIDI so I might got things wrong, but I'm having hard times to find a MIDI keyboard with 5-pins. Maybe real expensive ones have it tho...

A hard time? They nearly all do aside from newer ones. Grab something used at a thrift shop. If you're just starting out, you don't need something new and huge.
If anything, pick up one of these:
http://www.newegg.com/Product/Product.a … 10213400:s

17 bucks. Can't go wrong.

Yea that IS a good price, I picked one up at a thrift store for $25 and am very happy with it! Very good feel and nice size to enter notes into the PC. I suck playing a KB so it's fine for my lame one handed 'style' If you can really play, you would prob want a larger KB.
As to the Shifmore how-to, it's kind of a 'why?' thing for me. If you have the interface, why not just use DIN sockets on the Arduino? The Arduino needs to be setup to send and receive Midi anyway and cutting up the interface just makes it less flexible. I suppose if you really don't have the space, hardwiring the interface into the same case is good.
  If you really need USB Midi/Arduino I would port to a Teensy that supports USB Midi directly. Didn't Littlescale do a Teensy Arduinoboy?
Yogi

I have the rockbank keyboard, the miracle piano teaching system and a Casio DH-100. All have midi in and or out via a 5-pin DIN.

friendofmegaman wrote:

I'm just getting started with MIDI so I might got things wrong, but I'm having hard times to find a MIDI keyboard with 5-pins. Maybe real expensive ones have it tho...

A hard time? They nearly all do aside from newer ones. Grab something used at a thrift shop. If you're just starting out, you don't need something new and huge.
If anything, pick up one of these:
http://www.newegg.com/Product/Product.a … 10213400:s

17 bucks. Can't go wrong.

This thing looks badass!

But yah thanks for the advice I'll look for the proper MIDI kb I checked Amazon and ebay and the search returned all USB keyboards so I've got the false impression that 5-pin is not used anymore it was also backed up by this video where the dude says 5-pin are obsolete these days.

herr_prof wrote:

Very few USB keyboards have the ability to be midi
Host devices

I'm just getting started with MIDI so I might got things wrong, but I'm having hard times to find a MIDI keyboard with 5-pins. Maybe real expensive ones have it tho...

A hard time? They nearly all do aside from newer ones. Grab something used at a thrift shop. If you're just starting out, you don't need something new and huge.
If anything, pick up one of these:
http://www.newegg.com/Product/Product.a … 10213400:s

17 bucks. Can't go wrong.

Very few USB keyboards have the ability to be midi
Host devices

I'm just getting started with MIDI so I might got things wrong, but I'm having hard times to find a MIDI keyboard with 5-pins. Maybe real expensive ones have it tho...

UPDATE
Found this article http://shiftmore.blogspot.com/2010/01/q … r-usb.html I'm sure someone has tried that already could you please share you thoughts?

So it obviously possible to modify original arduinoboy to use single In or single Out jack. But how about single jack for both and its function (in or out) is defined by the mode?