Please help. I have Ubunto 16.04 LTS, I am using Arduino 1.8.5 to flash Marlin firmware to Anet A8 3d printer board. I have folled the instructions on Github and when I compile it gives me these error warnings:   In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:43:0: warning: "TIMER2" redefined  #define TIMER2  5  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:210:0: note: this is the location of the previous definition  #define TIMER2  6  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:44:0: warning: "TIMER2A" redefined  #define TIMER2A 6  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:211:0: note: this is the location of the previous definition  #define TIMER2A 7  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:45:0: warning: "TIMER2B" redefined  #define TIMER2B 7  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:212:0: note: this is the location of the previous definition  #define TIMER2B 8  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:47:0: warning: "TIMER3A" redefined  #define TIMER3A 8  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:214:0: note: this is the location of the previous definition  #define TIMER3A 9  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:48:0: warning: "TIMER3B" redefined  #define TIMER3B 9  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:215:0: note: this is the location of the previous definition  #define TIMER3B 10  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:49:0: warning: "TIMER3C" redefined  #define TIMER3C 10  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:216:0: note: this is the location of the previous definition  #define TIMER3C 11  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:50:0: warning: "TIMER4A" redefined  #define TIMER4A 11  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:217:0: note: this is the location of the previous definition  #define TIMER4A 12  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:51:0: warning: "TIMER4B" redefined  #define TIMER4B 12  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:218:0: note: this is the location of the previous definition  #define TIMER4B 13  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:52:0: warning: "TIMER4C" redefined  #define TIMER4C 13  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:219:0: note: this is the location of the previous definition  #define TIMER4C 14  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:53:0: warning: "TIMER5A" redefined  #define TIMER5A 14  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:221:0: note: this is the location of the previous definition  #define TIMER5A 16  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:54:0: warning: "TIMER5B" redefined  #define TIMER5B 15  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:222:0: note: this is the location of the previous definition  #define TIMER5B 17  ^ In file included from /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:257:0,                  from sketch/Marlin.ino.cpp:1: /opt/arduino-1.8.5/hardware/anet/avr/variants/sanguino/pins_arduino.h:55:0: warning: "TIMER5C" redefined  #define TIMER5C 16  ^ In file included from sketch/Marlin.ino.cpp:1:0: /opt/arduino-1.8.5/hardware/arduino/avr/cores/arduino/Arduino.h:223:0: note: this is the location of the previous definition  #define TIMER5C 18  ^ Sketch uses 103210 bytes (81%) of program storage space. Maximum is 126976 bytes. Global variables use 4171 bytes of dynamic memory. ... View more