What are you doing with this button? Are you turning power on and off? What's it's purpose? What do you mean by "take action"?

You can change the wiring to always "on":

VCC = ideal 3.3v, no more than 5V. Resistor = same rules

@Dave: I believe you can use that logic for robot bumper switches, imagine the robot hits the wall.

If the idea is to monitor switches states, can be problematic if the verification code takes longer and misses a transition.

I am asking what the op is doing with this switch. I think it's important to find out to offer the right answer and solution. It's odd that he first had it attached to a digital port.

Attached to digital port because that is what I thought it should be, but maybe not.

It is a stationary robot and I am using to determine if it gets lifted, knocked over, etc..

@Dave you're right, my initial concern was the voltage on the red pin, before serious damage.

but i missed something:

Quote:

I have a switch that is always closed. If it becomes open that is a condition that I take some action.

I would change the wiring (post 19)

Quote:

It's odd that he first had it attached to a digital port.

I have 6 bumper switches, 3 front, 3 back, you have more digital ports than analog ports so why not ?

@dbeard Can you provide more details ? you have our attention

It is a stationary robot and I am using to determine if it gets lifted, knocked over, etc..

also, why change to D19 instead of D20?

Trying to understand.

post 19 related to this conversation, not port 19.