Hi,
Welcome to the forum.
dawm:
I have a project (first time with Arduino, I have a Arduino UNO) where I'm using my vehicles fog light button and retaining its original function and adding the ability to hold the button for a few seconds to turn on/off another set of fog lights. Long story short.. I don't like adding some janky looking aftermarket switch to my vehicle and would like to re-purpose the OEM switch.
Is your fog light button a momentary ON button, or a press ON- press OFF mechanical type switch.
If the latter then you will not be able to detect how long you have you finger on the button.
Tom... 