Input "isolation"

this has come because or recent problems on project.

as is, pin pulled (internal resistor) , taken low when button pressed.

all , in theory.

the circuit has large pump near , if leads long, think noise getting arduino , hanging.
sure move wire is, still "work in progress" @ stage.


so wondering:
if put opto-isolator on pin , used pull pin low when led on, , have close possible arduino , use (say) 12v signal - resistor of course - help/work?

with is, can understand noise induced wire , cause sorts of problems.
using 12v rather 5v signal, make "signal noise ration" twice - , small bit.

i shall try re-routing wire, want have "plan b" if fails, can move on right away , not stuck needing ask.

i "wanting" protect arduino "oops" moments zap pins.
did 1 already.   not happy.

but now, i'm keeping options open.

hi,
opto-isolation approach. 

what wire using?  if use twisted pair of wires noise pickup reduced.

if use shielded twisted pair shield grounded arduino end ground (not connected on far end) better.

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