I am not aware of any libraries in CPAN that give you this functionality, but this might be good excuse to learn
. If you can figure out how to twiddle the LEDs in C/C++, then just wrap it up with XS so you can call into it with Perl. From a short term practicality standpoint this would probably be a largely futile effort, but from a scholarly point of view, just learning XS would make it worth your troubles.