I am fairly new to Arduino. As far I know all official Arduinos run on 5 volts. Or there is Arduino versions that run from 3.3V? I need use Arduino with devices which chipsets all use 3.3V logic level. Do I need modify Arduino to make it 3.3V powered, like described in this Tips, or there is another way? I plan get Arduino UNO R3 ATmega328P board (comes with bootloader for Arduino UNO ZT).

  • The best solutions to this are to move away from an antiquated ATmega to a modern MCU which achieves full performance on 3.3v. Commented Jul 29, 2017 at 18:15
  • Nucleo boards (ARM). And on Olimexino 32u4 it's even possible to switch between 3.3V and 5V. So many possibilities
    – KIIV
    Commented Jul 29, 2017 at 19:13

3 Answers 3


Arduino Pro Mini comes in 3.3v and 5v versions.

  • Arduino Pro Mini is minimalistic, semi-finished board that comes without pin headers, no on-board USB, and no built-in USB circuitry, so it requires additional components and FTDI TTL Level Serial Converter Cable that should be connected, so the whole construction isn't very handy.
    – minto
    Commented Jul 29, 2017 at 12:33
  • @minto. Soldering things is a basic ability here. FTDI is no-brainer; you need only one. The big plus: minimal footprint. Lately, I don't even solder pins; just solder the wires directly to the board for less hassle and to reduce overall height and fit the Pro Mini in tight spaces.
    – user31481
    Commented Jul 29, 2017 at 12:35
  • Soldering is not an issue, but I just preffer standalone device, with all required interfaces already built-in. As it not need to be pocket-size device, the minimal footprint just not required. Additionally, attaching external FTDI basic breakout board isn't convenient.
    – minto
    Commented Jul 29, 2017 at 13:09
  • @minto. Last, but not least, Pro Mini is breadboard friendly. You can put a Pro Mini, an OLED display (1.8") and several led and push buttons on a small breadboard: a whole project in the footprint of an Arduino Uno. The FTDI also comes handy with things like SMS 800 modules.
    – user31481
    Commented Jul 29, 2017 at 14:23
  • I correct myself. I was thinking about a 0.98" OLED display
    – user31481
    Commented Jul 29, 2017 at 23:24

You can use different possibilities:

  1. Use Arduinos which are already 3.3V by default (like Pro Mini, Due if I recall right)

  2. (removed after valid comment of minto below)

  3. Use 5->3.3V adapters, most general devices have adapters which can be bought separately (for under 1$) to convert 5 to 3.3V (including logic level converters)

  • 3
    I think the point 2) "Use the 3.3V pin on e.g. the Arduino Uno" is simply wrong: the Arduino Uno has a 3.3V power source, but the digital I/O pins are based on 5V, not 3.3V. We can't to make the I/O pins 3.3V, unless we are powering the Atmega at 3.3V also.
    – minto
    Commented Jul 29, 2017 at 16:29
  • True, I will remove it from the answer (was mixed up with powering in general) Commented Jul 29, 2017 at 17:53

What about just getting the bare chip so you can run it at whatever rail you want? Seems like the simplest and easiest solution.

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