Does anybody have a Schematic / Circuit Diagram of the Piface Digital,
i searched in all pdf's and everywhere else (i think :-)) an i cant find anything
(the "simplified schematic" is more where the connectors are located, not
exactly what i am seeking). Thanks for any help on finding this!
all the best
marcel
Ah, helpfully the schematics are not under anything labeled 'schematics' and buried on a blog 
I searched for these a couple of days ago, with google, and totally failed to find them. Searching for 'schematics' must have been my problem 
Lots of these folks really need to take a leaf out of whatever book the likes of Olimex/Beaglebone use and just put everything up on github.
Morgaine Dinova wrote:
Piface have some repos at Github -- https://github.com/piface -- but a brief poke around there turned up nothing.
yeah, I had a dig around in those expecting to find something useful but didn't. Finally ended up googling for the filename with little success and doing a general search on github for anything relating to piface.
Maybe they'd respond positively to a customer request that they place the schematic and other documentation up there?
Maybe they would, but then I'm not a customer 
Someone has actually commented on their blog yesterday asking them to repost and he got a suitably vague reply..
My interest was mostly academic anyway and triggered by some other recent comments on the Pi Rack here http://www.element14.com/community/videos/9289/l/pirack-introduction-video--piface-expansion-board-for-raspberry-pi#comment-25189 and here http://www.element14.com/community/people/mcb1/blog/2013/08/06/pi-rack
I actually don't have that much of a problem with adding a gpio expander like they've done, it was one of the first things I did with mine 
To make it worthwhile though, you need to properly document the design, otherwise it's much harder to use and you're absolutely right that you'll pay the price later.. The PiFace was seemingly developed by the University of Manchester school of computing science, you'd think such an education institution would understand the value of having decent documentation available wouldn't you ?
Yes the BBB is better suited, but even there I'd not have a problem with adding a gpio expander if it ever became necessary. Done properly using the facilities provided for it by the kernel, it's seamless, you just end up with 80 gpios instead of 64 (or whatever number) that are all useable through exactly the same interface.
