I'm wondering if a 3.3v input to the Pi's GPIO before it is set up will damage that pin.

2 Answers 2


I would suggest connecting 3.3V to any MOS device before it is powered up is a bad idea, as it risks reverse biassing the substrate. At the least you should use a series resistor to limit current.


It is perfectly legal to attach a input to the gpio before it is "setup". Although when plugging in wires it is a good idea to turn off your raspberry pi.

I suggest reading the gpio docs. Here is a pinout diagram of the gpio.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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