Curious to know if the Due inputs are 5V tolerant as the mbed. Thanks.
Answer's pretty clear from the bold writing on the product page
Ok I see. Its a pity… seemed like a good product. Guess I am staying with the mbed.
Warning: Unlike other Arduino boards, the Arduino Due board runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Providing higher voltages, like 5V to an I/O pin could damage the board.
However some pins may be 5v tolerant, I make no claim to be true, However some of the pins on the sam3 are, The uart and the i2c may be, according to the data sheet from atmel. (depending on exactly which chip you have) However bear in mind using i2c that the pull up resistors must have a min value of 10k ohm. This is to respect the maximum sink to ground current of the sam3. The older duino's could sink 40 ma or so but the sam really starts to sweat around 10 ma.
Serch ebay for " IIC I2C Level Conversion Module 5V-3V System For Arduino". to get the hardware to convert. use 10k pull up on the 3.3v side and 5k on the 5v side.
As far as a 5 v device reading the 3.3 out of the due on an input ther are two fixes,
One... just hook up the 3.3 out to the 5 input 3.3 is more than 2.5 and will in most cases produce a digital read of HIGH.
Two connect the aref pin of the 5v duino to the 3.3 v out pin (check for jumper and aref code requirements) and the 5v atmel will now gauge it's input 0 to 3.3 v.
Serial, tx due to rx on 5v device usually so far at 9600 works,,,
tx on 5v device through 5 k resistor to rx on due with 3.3 k resistor rx due to gnd, seems to be working for me.
Digital and analog read works the same way 5v dev to 5kresistor to pin and pin to3.3k resistor to gnd.
5v on 3.3 Device is playing with fire. I an in no way Qualified to say otherwise! Playing with this is not in any way my responsibility. What I get away with you may not!