The Arduino MKR WIFI 1010 product page says "The microcontroller on the MKR WIFI 1010 runs at 3.3V, which means that you must never apply more than 3.3V to its Digital and Analog pins. Care must be taken when connecting sensors and actuators to assure that this limit of 3.3V is never exceeded. Connecting higher voltage signals, like the 5V commonly used with the other Arduino boards, will damage the MKR WIFI 1010."

and yet it only has a 5V pin. I have a sensor that requires a 3.3V pin so I'm guessing my only option is to use a Logic Level Converter.

My question is if the MKR Digital and Analog pins can only take 3.3V, why is there only a 5V pin instead of a 3.3V pin to connect to a breadboard?

  • 1
    I agree that it is unclear and the documentation is not complete, but the VCC pin is the 3.3V output meant to power sensors. In the documentation tab of the MKR ZERO is explanation: store.arduino.cc/arduino-mkrzero
    – Jot
    Jan 27, 2019 at 0:39
  • Thanks @Jot If you add that as an answer I'll mark it as the solution.
    – Dan
    Jan 27, 2019 at 1:42

1 Answer 1


In short: VCC = 3.3V

The Arduino MKR WiFi 1010 board documentation is not complete. Well, at least they have the warning that the processor is running at 3.3V and the voltage levels of the pins should never be above 3.3V.

The page of the Arduino MKR ZERO has more information in the "documentation" tab. The VIN pin is the 5V power input, the 5V pin is unregulated 5V output (when the board is powered by USB or the VIN pin) and VCC is the regulated 3.3V output.

The term "VCC" means that it is the voltage at which the processor is running. Since it is a 3.3V Arduino board, it is the 3.3V voltage pin. That 3.3V should be used to power sensors. The "Tech Specs" tab at the MKR ZERO tells that it can supply up to 600 mA. That is the same for the MKR WiFi 1010, because the same AP2112K-3.3 voltage regulator is used.

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