guitar frequencies

Using Arduino Programming Questions
4

Ducaqabe:
thanks Magician

wen I compile the on that link, I got compile error, I think my arduino does'nt use cpp library

it does'nt recognize this line: FreqCounter::f_comp=10;
and I downloaded this file #include <FreqCounter.h>

Did you download the whole library from that page and install it in .../sketchbook/libraries/ ?