This project measures the period of any frequency applied to the Microcounteroller.
Pin INT(external interrupt) is used to detect each rising edge of the wave.
Timer1 is used the calculate the time of the wave period(Ton + Toff).
This is how it works:
1 - First rising edge is detected using INT(external interrupt).
2 - Timer1 will start counting.
3 - Second rising edge is detected using INT(external interrupt).
4 - Timer1 will stop counting because from first rising edge to the second rising edge is a complete wave which means the period(Ton + Toff).
5 - Calculate period.
6 - Display results on LCD.