Series Resistor With a Button?


Is it ever considered a good idea to place a resistor in series with a button when you use a pin in INPUT_PULLUP mode? Or does it not even matter?



Never necessary and a waste of resistors!

Good to know, thanks!

Hmm, what if... incorrect settings on the port like high output and the button pressed?
The 1k resistor cannot hurt.

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Look at the following diagram and check if you really need a resistor in series with a switch when the internal pull-up resistor (Rip) is enabled.

I would say definitely not ... assuming that the reading is being taken at the bottom of Rip.

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and possible ESD protection.
The resistor cost only little and adds (little) protection. I wouldn't use this resistor (because I am careless) but adding it is not 100% waste.

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