In Post #23 I wrote
vagulus:
Surely everything goes back to Earth (i.e. the planet) in the end. Both the Red Wing and the UNO have power supplies earthed to Earth, and they are commonly linked earth to earth. I don't understand what you mean by a clean ground between sensor and Arduino much less a second ground path.
Can someone please clarify this?
I have always worked on the principle that an earth is an earth is an earth. Have I been deluding myself all these years?