PCB DESIGN - All In One 32 inputs with 74HC4851

[Juze]

The pics are edited to my second-last post in this thread. They're on page 8 http://www.megadrum.info/forums/viewtopic.php?p=2584#p2584

We re-try it wednesday, we're pretty sure that this time we will success.
We use sodiumpersulfate aswell. I think we will also make drillings in Elias's school
Hopefully we do it better this time

-Juze aka Ghroath

[operators123]

bumping an old thread, but is this still worth making? I want to make an all in one board megadrum with 32 inputs and this is the only one I can find. I like this because it doesn't need loads of components, making it cheaper and easier to make than the newer 56 input designs.
Would it still be worthwhile making this?

[ignotus]

It will work perfectly well, but you can always use the newer 56 input design (I think a few component values have changed since then among other things, though nothing major) and leave out the components/inputs you don't need.

[operators123]

Ah right, thanks for the reply, I might try that, but I'm a bit confused as to how to eliminate the inputs as I'm not sure which parts to keep on the schematic and what to get rid of, while making the circuit still work.

Also, is there a proper schematic for this 32 input board? I can't seem to find one.

[ignotus]

Just omit all the components associated with inputs 33 - 56; I think it'd just be three multiplexers and the three resistors between them and the atmega mcu. I'd go with the latest schematic and pcb design - the only real difference are the extra multiplexers and inputs.