Unify AVR90USB: Pins cleanup

Marlin/pins_AZTEEG_X3_PRO.h

@@ -146,7 +146,7 @@
 // Misc. Functions
 //
 #if ENABLED(CASE_LIGHT_ENABLE)  && PIN_EXISTS(CASE_LIGHT) && defined(DOGLCD_A0) && DOGLCD_A0 == CASE_LIGHT_PIN
-  #undef DOGLCD_A0            // steal pin 44 for the case light; if you have a Viki2 and have connected it
+  #undef DOGLCD_A0            // Steal pin 44 for the case light; if you have a Viki2 and have connected it
   #define DOGLCD_A0        57 // following the Panucatt wiring diagram, you may need to tweak these pin assignments
                               // as the wiring diagram uses pin 44 for DOGLCD_A0
 #endif

Marlin/pins_MEGATRONICS_3.h

@@ -131,7 +131,7 @@
 #define SDSS               53
 #define LED_PIN            13
 #define PS_ON_PIN          12
-#define CASE_LIGHT_PIN     45 // try the keypad connector
+#define CASE_LIGHT_PIN     45   // Try the keypad connector
 
 //
 // LCD / Controller

Marlin/pins_MIGHTYBOARD_REVE.h

@@ -211,12 +211,12 @@
 //
 #ifdef REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
 
-  #define LCD_PINS_RS           33 // C4, LCD-STROBE
+  #define LCD_PINS_RS       33   // C4: LCD-STROBE
-  #define LCD_PINS_ENABLE       72 // J2, LEFT
+  #define LCD_PINS_ENABLE   72   // J2: LEFT
-  #define LCD_PINS_D4           35 // C2, LCD-CLK
+  #define LCD_PINS_D4       35   // C2: LCD-CLK
-  #define LCD_PINS_D5           32 // C5, RLED
+  #define LCD_PINS_D5       32   // C5: RLED
-  #define LCD_PINS_D6           34 // C3, LCD-DATA
+  #define LCD_PINS_D6       34   // C3: LCD-DATA
-  #define LCD_PINS_D7           31 // C6, GLED
+  #define LCD_PINS_D7       31   // C6: GLED
 
   #define BTN_EN2           75   // J4, UP
   #define BTN_EN1           73   // J3, DOWN
@@ -275,9 +275,6 @@
 
 
 
-
-
-
 // Check if all pins are defined in mega/pins_arduino.h
 #include <Arduino.h>
 static_assert(NUM_DIGITAL_PINS > MAX_PIN, "add missing pins to [arduino dir]/hardware/arduino/avr/variants/mega/pins_arduino.h based on fastio.h"

Marlin/pins_RAMPS.h

@@ -251,6 +251,7 @@
   #if ENABLED(NEWPANEL)
 
     #if ENABLED(REPRAP_DISCOUNT_SMART_CONTROLLER)
+
       #define BEEPER_PIN        37
 
       #define BTN_EN1           31
@@ -265,26 +266,32 @@
       #endif
 
     #elif ENABLED(REPRAPWORLD_GRAPHICAL_LCD)
+
       #define BTN_EN1           64
       #define BTN_EN2           59
       #define BTN_ENC           63
       #define SD_DETECT_PIN     42
+
     #elif ENABLED(LCD_I2C_PANELOLU2)
-      #define BTN_EN1 47  // reverse if the encoder turns the wrong way.
+
+      #define BTN_EN1           47
       #define BTN_EN2           43
       #define BTN_ENC           32
       #define LCD_SDSS          53
       #define SD_DETECT_PIN     -1
       #define KILL_PIN          41
+
     #elif ENABLED(LCD_I2C_VIKI)
-      #define BTN_EN1 22  // reverse if the encoder turns the wrong way.
+
-      #define BTN_EN2 7   // http://files.panucatt.com/datasheets/viki_wiring_diagram.pdf
+      #define BTN_EN1           22 // http://files.panucatt.com/datasheets/viki_wiring_diagram.pdf explains 40/42.
-                          // tells about 40/42.
+      #define BTN_EN2            7 // 22/7 are unused on RAMPS_14. 22 is unused and 7 the SERVO0_PIN on RAMPS_13.
-                          // 22/7 are unused on RAMPS_14. 22 is unused and 7 the SERVO0_PIN on RAMPS_13.
+
       #define BTN_ENC           -1
       #define LCD_SDSS          53
       #define SD_DETECT_PIN     49
+
     #elif ENABLED(VIKI2) || ENABLED(miniVIKI)
+
       #define BEEPER_PIN        33
 
       // Pins for DOGM SPI LCD Support
@@ -305,7 +312,7 @@
       #define STAT_LED_BLUE_PIN 35
 
     #elif ENABLED(ELB_FULL_GRAPHIC_CONTROLLER)
-      #define BTN_EN1 35  // reverse if the encoder turns the wrong way.
+      #define BTN_EN1           35
       #define BTN_EN2           37
       #define BTN_ENC           31
       #define SD_DETECT_PIN     49
@@ -344,12 +351,12 @@
 
       // buttons are directly attached using AUX-2
       #if ENABLED(REPRAPWORLD_KEYPAD)
-        #define BTN_EN1 64 // encoder
+        #define BTN_EN1         64
-        #define BTN_EN2 59 // encoder
+        #define BTN_EN2         59
-        #define BTN_ENC 63 // enter button
+        #define BTN_ENC         63
-        #define SHIFT_OUT 40 // shift register
+        #define SHIFT_OUT       40
-        #define SHIFT_CLK 44 // shift register
+        #define SHIFT_CLK       44
-        #define SHIFT_LD 42 // shift register
+        #define SHIFT_LD        42
       #elif ENABLED(PANEL_ONE)
         #define BTN_EN1         59 // AUX2 PIN 3
         #define BTN_EN2         63 // AUX2 PIN 4
@@ -357,7 +364,7 @@
       #else
         #define BTN_EN1         37
         #define BTN_EN2         35
-        #define BTN_ENC 31 // the click
+        #define BTN_ENC         31
       #endif
 
       #if ENABLED(G3D_PANEL)