Hello, I have been using udoo board as arduino due board to learn programming by using external computer that uploads sketches. I have been using 5V and GND pins to do some programming. However, I read about arduino due on the arduino.cc and it told me I should use 3.3V logic for pins, otherwise board is destroyed. I talked to a colleague and he said I should avoid using 5V pin and use 3.3V instead. What I do not understand that is that my board seems to be fine and secondly I can not find 3.3V on the udoo board. Can anyone help me plz?!!!!!