I am using Arduino mega and a sensor shield (picture attached below). I need to connect three different wires to 3.3 V input. Can anybody suggest how can I achieve the same? What voltage do the VCC pins of all digital and analog pins on the sensor shield have?

enter image description here

  • Is there a pin marked with 3.3 or similar? If not, you will need an external voltage regulator. If yes, you should make sure, that is can provide enough current for the sensors
    – chrisl
    Apr 21, 2019 at 11:20

2 Answers 2


They are all 5V as the Mega2560 uses 5 V logic. However, there is a 3V3 pin at the bottom, second pin from the left, that you could use:

Mega sensor shield

However, unfortunately, the pin isn't protruding above the shield, so you'll have to make an ugly solder link to the top of the pin. Either that, or remove the row of pins and replace with a female header (carefully avoiding the SD card pins):

Female header pins

As an aside, the Iteaduino MEGA 2560 works at 3V3 but unfortunately the Mega shield that you have won't fit it.

Iteaduino MEGA 2560

The Uno equivalent of your shield will fit it though:

Uno sensor shield

  • I guess the shield would still provide 5 V from the 5 V pin of the 3.3 V Mega
    – Juraj
    Aug 13, 2022 at 5:27

I fix it solding into the board sensor shield the point where there is the pin 3.3v

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.