Cleanup unused pins and connectors

- removed E_MUX2_PIN and updated function
- unmarked #define DISABLE_MAX_ENDSTOPS, Prusa i3 MK2(s) doesn't use these end stops ... M119 shows now just used end stops

Firmware/Configuration.h

@@ -252,7 +252,7 @@ your extruder heater takes 2 minutes to hit the target on heating.
 const bool X_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
 const bool Y_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
 const bool Z_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of the endstop.
-//#define DISABLE_MAX_ENDSTOPS
+#define DISABLE_MAX_ENDSTOPS
 //#define DISABLE_MIN_ENDSTOPS
 
 // Disable max endstops for compatibility with endstop checking routine

Firmware/Marlin_main.cpp

@@ -5629,7 +5629,6 @@ case 404:  //M404 Enter the nominal filament width (3mm, 1.75mm ) N<3.0> or disp
 
 		  pinMode(E_MUX0_PIN, OUTPUT);
 		  pinMode(E_MUX1_PIN, OUTPUT);
-		  pinMode(E_MUX2_PIN, OUTPUT);
 
 		  delay(100);
 		  SERIAL_ECHO_START;
@@ -5639,25 +5638,21 @@ case 404:  //M404 Enter the nominal filament width (3mm, 1.75mm ) N<3.0> or disp
 		  case 1:
 			  WRITE(E_MUX0_PIN, HIGH);
 			  WRITE(E_MUX1_PIN, LOW);
-			  WRITE(E_MUX2_PIN, LOW);
 
 			  break;
 		  case 2:
 			  WRITE(E_MUX0_PIN, LOW);
 			  WRITE(E_MUX1_PIN, HIGH);
-			  WRITE(E_MUX2_PIN, LOW);
 
 			  break;
 		  case 3:
 			  WRITE(E_MUX0_PIN, HIGH);
 			  WRITE(E_MUX1_PIN, HIGH);
-			  WRITE(E_MUX2_PIN, LOW);
 
 			  break;
 		  default:
 			  WRITE(E_MUX0_PIN, LOW);
 			  WRITE(E_MUX1_PIN, LOW);
-			  WRITE(E_MUX2_PIN, LOW);
 
 			  break;
 		  }

Firmware/pins.h

@@ -67,7 +67,6 @@
 
 #define E_MUX0_PIN 17
 #define E_MUX1_PIN 16
-#define E_MUX2_PIN 84
 
 
 #endif
@@ -229,7 +228,6 @@
 
 #define E_MUX0_PIN 17
 #define E_MUX1_PIN 16
-#define E_MUX2_PIN 84
 
 
 #endif

Firmware/ultralcd.cpp

@@ -3264,31 +3264,26 @@ void change_extr(int extr) { //switches multiplexer for extruders
 
 	pinMode(E_MUX0_PIN, OUTPUT);
 	pinMode(E_MUX1_PIN, OUTPUT);
-	pinMode(E_MUX2_PIN, OUTPUT);
 
 	switch (extr) {
 	case 1:
 		WRITE(E_MUX0_PIN, HIGH);
 		WRITE(E_MUX1_PIN, LOW);
-		WRITE(E_MUX2_PIN, LOW);
 		
 		break;
 	case 2:
 		WRITE(E_MUX0_PIN, LOW);
 		WRITE(E_MUX1_PIN, HIGH);
-		WRITE(E_MUX2_PIN, LOW);
 		
 		break;
 	case 3:
 		WRITE(E_MUX0_PIN, HIGH);
 		WRITE(E_MUX1_PIN, HIGH);
-		WRITE(E_MUX2_PIN, LOW);
 		
 		break;
 	default:
 		WRITE(E_MUX0_PIN, LOW);
 		WRITE(E_MUX1_PIN, LOW);
-		WRITE(E_MUX2_PIN, LOW);
 		
 		break;
 	}
@@ -3296,7 +3291,7 @@ void change_extr(int extr) { //switches multiplexer for extruders
 }
 
 static int get_ext_nr() { //reads multiplexer input pins and return current extruder number (counted from 0)
-	return(4 * READ(E_MUX2_PIN) + 2 * READ(E_MUX1_PIN) + READ(E_MUX0_PIN));
+	return(2 * READ(E_MUX1_PIN) + READ(E_MUX0_PIN));
 }