Capturing timer value based on external interrupt , leveraging the 62.5nsec (16MHz) resolution) of the ATMEGA328 on the Arduino Uno

@JohnRob -Agreed...in the process of doing so.

Btw, reviewing NIck Gammon's examples (reply #12 on Nick's webpage), it seems he's using instruction bit() set individual bits in various registers. However, from the Arduino reference documentation, the bit() instruction is used to read the register since, as I understand it, it returns the bit's value. I noticed that @johnwasser's code uses the _BV macro instead. Has the functionality of bit() changed since Nick created his examples? or am I totally misunderstanding the code?

Thanks!