What is right method to pass led info from processing to arduino

Processing Electronics (Arduino, etc.)
8

sorry,
the Arduino IDE monitor
is a terminal software
but you could use any other “serial terminal” software
but no idea whats good on MAC

so , where is your code, the minimal version what just deal with
processing serial and arduino serial,
no CP5, no LED…
cut it down and make it a extra little project to solve that problem.