Arduino: 1.8.1 (Windows 7), Board: "Arduino/Genuino Uno" C:\Users\Sonny\Desktop\Chronos\Chronos.ino:29:61: fatal error: Charlieplexing.h: No such file or directory #include // Library for driving the LEDs ^ compilation terminated. exit status 1 Error compiling for board Arduino/Genuino Uno. This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences.