Bandpass filter

Those errors are from Keil

From arduino I have this one:

C:\Users\OWNER\Documents\Arduino\sketch_sep26b\sketch_sep26b.ino:39:18: fatal error: main.h: No such file or directory

The filter code was gene was generated by
https://www-users.cs.york.ac.uk/~fisher/mkfilter/trad.html
Much easer to use than Matlab

This is my first project with programing, beginner with Arduino.