باتشکر
کلیه مراحل را انجام دادم ولی این پیغام و ارور رو می ده
Arduino: 1.6.9 (Windows 7), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

sketch\Marlin_main.cpp: In function 'void gcode_M250()':

Marlin_main.cpp:5585: error: 'lcd_setcontrast' was not declared in this scope

if (code_seen('C')) lcd_setcontrast(code_value_short() & 0x3F);

^

In file included from sketch\Marlin_main.cpp:35:0:

Marlin_main.cpp:5587: error: 'lcd_contrast' was not declared in this scope

SERIAL_PROTOCOL(lcd_contrast);

^

sketch\Marlin.h:84:43: note: in definition of macro 'SERIAL_PROTOCOL'

#define SERIAL_PROTOCOL(x) MYSERIAL.print(x)

^

exit status 1
'lcd_setcontrast' was not declared in this scope

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