But if the duration is > 65535 ticks, the calculated duration will be wrong, no? There is no mechanism to count how many times TCNT1 overflows, so it will be incorrect if the duration of what you are timing exceeds 65535 ticks.
That is correct, yes. I had erroneously understood that the author meant "all durations between 0 and 65535 ticks" as "any duration between the device's 0th and 65535th tick", my bad... Also makes this entire thread obsolete, but FWIW, one shouldn't be attempting to measure a duration that can't even be contained in the variable's bit width. Some workarounds would be to add more bits, slow down the tickrate or add overflow counters.
