Sounds like a great idea!
I wonder how fast it would have to react… so say you had a 50 meter cable with a break in it somewhere… say at the 25 meter mark, then that would be 50 meters round trip for the pulse to go out and come back…
Let’s assume that the pulse was travelling at near the speed of light (it slows down in copper, but I don’t have that factor)… c = 299 792 458 m/s
So to travel 50 meters would be… 50 / 299 792 458 = 1.66782048 × 10-7 sec
or 0.16 microsecond…
That seems to me that you would need a processor that is sampling at the gigahertz range. So too fast for the little CPU in the Nano V2 to capture as an echo.
That being said, there is another way to do it and that would be to use a beat oscillator to create an interference pattern that you can measure more easily. This is what high-end DGPS units use to get centimeter accuracy.
But I think it’s beyond the skills of most DIY… although people on this forum always surprise me!
Karen