Frequency Counter

There are some frequency counter design available in the web using PIC as main controller. Mostly uses LCD as display because the PIC is freed from display scanning task. LCD is more expensive than the 7-segment and has less readability.

The challenge here is to use 7-segment as display to make the cost lower, but still maintain the accuracy. My approach is to use state machine in the software design. With state machine, the PIC is like performing multiple task in a specific period of time. The code must be examined line per line to make sure that each state will take an exact amount of machine cycle.