Markus_L811:
Yes saw it on this http://arduino.cc/en/uploads/Main/arduino-Due-schematic.pdf.It's true not an good move to have 5V on an 3.3V SPI some Sparcfun Shields use this Pin to detect the voltage too so they are dangerous too. Can you explain an bit more what are you have done so I can think about it.
But it musst be possible too set each Pin high and low seperatly so you can detect if it works and you can use the pins as intput to check the other way. --> Serial echo
I have been trying to get an spi 7segment display running, and have tried all variations on the spi outputs, nothing worked, and sometimes I got an segment of an digit lighting, everything was very flakey.
Really hope that I didn't break the Due with this. I tried to use gnd+vcc from the spi next to the SAM, and tried mosi, ss, spck etc from that header, and the headers around the board, nothing worked. Wery close to throwing the crap in the shredder..
Luckily Graynomad is now creating an proper pinout map for this board, so I will try again in the weekend.