3.3V, like the Due, that's unfortunate. This means it won't be compatible with most of the Uno shields, or 90% of the sensors on the market.
Kinda wish Arduino had gone with something with wireless stuff built in, like the Linkit One or RFduino.
Kinda wish Arduino had gone with something with wireless stuff built in, like the Linkit One or RFduino.
Are you sure about that? 3.3v is extremely common in the industry, to the extent that a lot of hobbyist 5v stuff has to be level shifted.
These are among the lowest power chips in the world, regular bleeding edge stuff.
Higher voltage means higher power, so there is a race to get as low as possible.
Internally, the D21 core runs at 1.2V. (There's an internal regulator that needs at least 1.62V coming in.)
But anything above that is just a waste of energy (besides the fact that the highest clock speeds need 2.7V minimum for 0 or 1 wait states).
They allow it, for compatibility, but you can see why even 3.3V is dying.
The shields will be happily redesigned.
Lots of sensors are happy at 3.3V though and many breakout boards are built to accept both 3.3V & 5V (with a level converter to take 5V down to 3.3V).