Hi Ray,
I totally forgot about the internal esp pull up resistor, have been tricked by the inline one, thanks for the explanations 👍
Anyway, internal pull up was not enough for my situation (25m of unshielded cable, who runs along other 220v cables) and adding another one as described makes it work as expected, no more floating voltage on SN1 input.
Is there any way to ensure the internal pull up is actually enabled and mesure it’s value ?
Thx