BACKGROUND I have a project which involves using various 3.3 volt devices and the Arduino Due might make sense but I would also like to use the Gameduino 3X. The GD3X documentation says that it's a 3.3 volt device with a 5 - 7 volt power input and that it is level shifted and is 'tolerant' of 5 volts. I assume that the Gameduino may work but I guess its data lines will be 5 volt out and could damage the Due. Is this the case? If so it would mean that I would have to use a level shifter between the two - that's possible but just a bit of a pain.