• It's a 100% Arduino pro micro Compatible Board.
  • Chip: ATmega32u4
  • Board Mode: LEDNARDO R3
  • Operating frequency: 16MHz
  • Working voltage: 5V
  • Input voltage: 7-12V
  • Digital IO port: 20
  • PWM channel: 7
  • Analog input: 12
  • Maximum current of 5V digital/analog port: 40mA
  • Maximum current of 3.3 V digital/analog port: 50 mA

What do I feed the Arduino Uno? 7-12V or 5V?

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  • 2
    \$\begingroup\$ Feed it with what you like. 7-12 V through the regulator input, or 5 V through the 5 V input. \$\endgroup\$
    – Neil_UK
    Oct 17, 2021 at 13:25
  • \$\begingroup\$ Downvoting and voting to close a beginners question. What a warm welcome they get on ee.se \$\endgroup\$
    – Passerby
    Oct 18, 2021 at 16:01
  • \$\begingroup\$ @Neil_UK I still wouldn't feed it with unregulated 5v though 5v pin, instead I'd do 5v though Vin or even 12v through the same pin. Then again, I really only use USB, I don't deal much with the care and feeding of Arduinos. \$\endgroup\$
    – Proxy303
    Oct 18, 2021 at 19:40

2 Answers 2


You can supply it either with

  • 5V via USB
  • 7-12V via the barrel jack, or
  • 7-12V via the Vin pin

According to this source (first google result for "arduino how supply voltage").


The working voltage is meant to tell you what the regulator outputs and what the electronics works at (such as the MCU). That in turn helps you know what the I/O voltage levels are. It also means that if there is a power pin that bypasses the regulator to feed the logic directly, then it needs to be a good, steady, clean 5V.

The input voltage of 7-12V would be through the regulator.


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