If I want to use two wires to detect water in the basement. I was wondering if I can just put 5V from the voltage regulator down on one probe, and then 1/2 inch away put in the other probe for the input to the ATMega? What if standing water is next to a pipe? Or somehow conducts to ground? Will I need to put a resistor on the 5V line just in case so I don’t short out the voltage regulator?
I’m also wondering what happens when the water conducts to a ground - would the ATMega see the 5V if it’s being pulled down to ground?
I attached a drawing of what I was thinking.
Edit: I see from the replies I missed a couple of details: see my reply in post #11.