I am newbie in Arduino (using UNO) and as I have 2 components that I wish to connected that one needs 5V and the other need the 3.3V, is it safe to connected them together next to each other?

  • In general, yes: you would just connect the 5v component to the Arduino's 5v output pin, and the 3.3v component to the Arduino's 3.3v output pin. They should share the same ground connection. Just make sure not to give the 3.3v component 5v power.
    – Jerry
    Commented Nov 7, 2015 at 15:15
  • You may put a potentiometer to change and organize the voltage, if you need.
    – Bay
    Commented Dec 7, 2015 at 21:52

1 Answer 1


If a component needs 5V it must be connected to 5V. If it needs 3.3V it must be connected to 3.3V. Connecting a 3.3V component to a 5V supply is a sure fire way of destroying it.

Furthermore, since the Arduino's main chip is a 5V device, if you want to connect it to a 3.3V device you must use some form of level translation so that the 5V signals from the Arduino don't damage the 3.3V device. Also it may (though not always) be necessary to convert the signals from the 3.3V device to a level that the Arduino can understand (5V).

  • "sure fire way" - pun intended? Commented Dec 7, 2015 at 19:11

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