Hephestos i3 problems with color mixing firmware for diamond hotend

enterAusername

Hello.  I am a complete beginner with reprap, and I am currently building a Prusa i3 Hephestos with a diamond hotend according to this guide:
http://www.reprap.org/wiki/Repetier_Color_Mixing
The building of the hephestos has gone fine, however the firmware is EXTREMELY confusing! I am following the (very lacking) instructions in the wiki exactly, however I cannot even get the firmware to upload to the arduino mega. I know little to nothing about arduino, so I am unable to interpret the errors.  Here is a link to the error code: https://pastebin.com/CwV8YUSe can someone PLEASE help me figure this out? i have been trying for about a month now. If someone knows how to get the firmware working, please let me know THANKS!!!

enterAusername

I dont know what the red text highlight thing is, sorry.  Also, I started with  this firmware: http://www.thingiverse.com/thing:910752 and just added 2 extruders and checked the "mixing extruder" and "shared heater" options. those are the only changes. also, I am able to get the unedited version of http://www.thingiverse.com/thing:910752
to upload fine.

Repetier

Configuration.h:170:29: error: ‘TEMP_3_PIN’ was not declared in this scope

 #define EXT2_TEMPSENSOR_PIN TEMP_3_PIN

means you have selected 3rd extruder but as you see from error message the selected board doe snot have a 3rd extruder output. You need to select your board and it should have enough drivers so you can safely select the predefined driver sockets. If you are using e.g. RAMPS board it has only 2 extra drivers whcih are then extruder 0 and 1, but 2 .. 5 are undefined then.

enterAusername

Repetier said:

Configuration.h:170:29: error: ‘TEMP_3_PIN’ was not declared in this scope

 #define EXT2_TEMPSENSOR_PIN TEMP_3_PIN

means you have selected 3rd extruder but as you see from error message the selected board doe snot have a 3rd extruder output. You need to select your board and it should have enough drivers so you can safely select the predefined driver sockets. If you are using e.g. RAMPS board it has only 2 extra drivers whcih are then extruder 0 and 1, but 2 .. 5 are undefined then.

I am using this guide http://reprap.org/wiki/Adding_more_extruders  in order to add more extruder controllers. i added this code

#define E2_STEP_PIN        64
#define E2_DIR_PIN         59
#define E2_ENABLE_PIN      44

to the firmware. also, there are only supposed to be 3 extuders, not 5. there must have been
an error in the preconfigured firmware here: http://www.reprap.org/wiki/Repetier_Color_Mixing 

Repetier

They write to make this:

In Pins.h (scroll down into the “RAMPS pin assignment” section or the board matching your setup) make sure the following lines are present, if not add them:

#define ORIG_E2_STEP_PIN        64
#define ORIG_E2_DIR_PIN         59
#define ORIG_E2_ENABLE_PIN      44

#define E2_PINS ORIG_E2_STEP_PIN,ORIG_E2_DIR_PIN,ORIG_E2_ENABLE_PIN,

change to ramps pins.h definition as they have a extension board for extra driver. 
With that you can use Extruder 2, but you did not add it correct and even worse
different code.