most basic usb version

[ignotus]

You shouldn't see a screen full of blocks - just the bottom line of each "block". Your screen seems to indicate that all the inputs are sending full velocity messages, so there must be a wiring mistake somewhere.

Edit: I had this behaviour because of faulty grounding. It may be because of something else but it's worth checking for continuity between all your ground points.

[Stienoo]

It was indeed an grounding error :O
Everything works fine right now! (even usb-midi connection)

Now the real work begins, building an E-drum and find the right settings.
I let know when it's finished!

Really thanks to ignotus for the help

[ignotus]

You're welcome, glad to be of assistance.

Good job you had an LCD, eh?

[Stienoo]

Yeah you're right

Just so I don't do stupid things:
The digital board stays the same for the 56 inputs version and I just have to buy an Atmega644 and replace my Atmega32 with it and add some more multiplexers?

[ignotus]

Yeah, it's a drop-in replacement and you just add the multiplexers you want and connect them to the corresponding pins of the Atmega.