karlok:
Hello,to capture changes of a pin's voltage, I decided to use an interrupt.
However, for me, it is very important to know how much time was between this interrupt triggered, and the one before!
How to do this? I was told, that "micros()" didn't work.
micros() should work.
OTOH if you absolutely must have precise timing you should probably use a hardware timer. Start a hardware timer going in the first interrupt then read it in the next one. Programming timers is quite easy. Grab a datasheet and look for a 16 bit timer on your chip.