Ecco qui gli errori che mi segnala:
In file included from _3.ino:3:
/Users/pc1/Documents/Arduino/libraries/ServoTimer2-master/ServoTimer2.h:103: error: 'byte' does not name a type
/Users/pc1/Documents/Arduino/libraries/ServoTimer2-master/ServoTimer2.h:105: error: 'byte' does not name a type
/Users/pc1/Documents/Arduino/libraries/ServoTimer2-master/ServoTimer2.h:121: error: 'boolean' does not name a type
/Users/pc1/Documents/Arduino/libraries/ServoTimer2-master/ServoTimer2.h:141: error: 'boolean' does not name a type