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

Projects Programming
44

The official way to write an empty interrupt vector is shown here
(avr-libc: <avr/interrupt.h>: Interrupts)

Instead of the empty vector or with the use of return, use instead

EMPTY_INTERRUPT(TIMER1_OVF_vect);

Alternatively, you can make an active overflow vector and increment an overflow count, which is what you will do if you actually use the overflow vector.