Due versus Mega2560 - voltages

I'm a bit new to the Arduino range and until now have been playing with the ATMega2560 - simple enough.

Been playing with USB and SPI, ADC, PWM and other stuff but trying to be smart I fried my 2560 (they don't like 12 VDC on the I2C ports - long story - mostly of impatient stupidity.

I've ordered a replacement 2560 and also a Due, the pin voltages on the Due concern me though, in particular the I2C / SPI - I'm assuming that these can still handle 5VDC.

And on the SPI front I'm used to using the block of pins 50 to 53 on the 2560 - seems that this changes on the Due but it isn't really clear where too. I can't use the 'designated' SPI block in the centre of the board with the shield that I currently use as it is obscured and the shield doesn't make it available (Arduino Mega V2). I looked into the SPI library in 'sam' but there doesn't seem to be the same pin allocation i.e.

pinMode(SCK, OUTPUT); pinMode(MOSI, OUTPUT);

as there is on the 2560 / avr processors.

The way I read things SPI is only available on the Due via the SPI pins near the processor.

Can anyone confirm the I2C and SPI pin voltages are 5VDC capable on the Due and also that the only place to do SPI on a Due is on the block of six pins near the processor.

the pin voltages on the Due concern me though, in particular the I2C / SPI - I'm assuming that these can still handle 5VDC.

Have you ever heard the saying about "assume" making an ass out of "u" and "me"?

Sure have - that's why I'm asking - the pin out diagram I have shows 5V but it's coloured red with a yellow triangle / exclamation mark.

Given that the bulk of USB devices - including PC's are 5VDC on USB ports - kind of makes the Due a poor purchase decision - just fancied comparing the 8bit to the 32bit.

Given that the bulk of USB devices - including PC’s are 5VDC on USB ports

I thought we were talking I2C?

We are kind of because I include SPI in that - I have devices that take power from SPI and they need 5VDC.

By Philips own specification the I2C can be either 3.3 or 5.0 …

So what can the Due handle - the pinout shows 5V in red and specifies no more than 3.3 VDC on I/O pins - but then it doesn’t make it clear whether it regards I2C or SPI as I/O pins.

If they're not input or output pins, what do you think they could be?

I'm not that dumb -

I'm just confirming that the I2C and SPI pins labelled 5V do in fact provide 5V not 3.3 and that they won't get messed up subject to the 130ma limit.

I ask also because I have provided power to the 2560 via an SBUS connection - and that was 5V - I need to know if I need to disconnect the +ve from devices such as my receiver if I power it from elsewhere.