Hi,
http://highlyliquid.com/midi-accessories/midi-connector-inline/midi-jack-inline.jpg will be exactly the same than the connector I showed, and the other one will be in mirror.
I'm sorry, I can't really test the led thing right now, I have currently a problem with my hardware. :-/ I did this two times, in one case a consolidated the soldering on the veroboard and it doesn't work since :o The other case, I went from breadboard to veroboard and now...
So I have to debug this, but it doesn't seem so easy... But I could try the LED to help me !
Middle C is just 60 because MIDI begins at the -1 octava.
Note on 0x90 to 0x9F
Note off 0x80 to 0x8F but often note on with 0 velocity is used instead of note off!
The one thing I still don't understand is:
Why is the code referring to middle c as 36(0x24), though midi uses 60(0x3c) as middle c?
Which code are you talking about?