SINGLENOZZLE: EXTRUDERS versus HOTENDS

9 years ago · cd441ce652
50 changed files with 550 additions and 458 deletions
--- a/Marlin/Conditionals.h
+++ b/Marlin/Conditionals.h
@ -535,6 +535,21 @@
  #define HAS_PID_HEATING (ENABLED(PIDTEMP) || ENABLED(PIDTEMPBED))
  #define HAS_PID_FOR_BOTH (ENABLED(PIDTEMP) && ENABLED(PIDTEMPBED))

+  /**
+   * SINGLENOZZLE needs to differentiate EXTRUDERS and HOTENDS
+   * And all "extruders" are in the same place.
+   */
+  #if ENABLED(SINGLENOZZLE)
+    #define HOTENDS 1
+    #undef TEMP_SENSOR_1_AS_REDUNDANT
+    #undef HOTEND_OFFSET_X
+    #undef HOTEND_OFFSET_Y
+    #define HOTEND_OFFSET_X { 0 }
+    #define HOTEND_OFFSET_Y { 0 }
+  #else
+    #define HOTENDS EXTRUDERS
+  #endif
+
  /**
   * ARRAY_BY_EXTRUDERS based on EXTRUDERS
   */
@ -551,15 +566,20 @@
  #define ARRAY_BY_EXTRUDERS1(v1) ARRAY_BY_EXTRUDERS(v1, v1, v1, v1)

  /**
-   * With SINGLENOZZLE all "extruders" are in the same place
+   * ARRAY_BY_HOTENDS based on HOTENDS
   */
-  #if ENABLED(SINGLENOZZLE)
-    #undef EXTRUDER_OFFSET_X
-    #undef EXTRUDER_OFFSET_Y
-    #define EXTRUDER_OFFSET_X { 0 }
-    #define EXTRUDER_OFFSET_Y { 0 }
+  #if HOTENDS > 3
+    #define ARRAY_BY_HOTENDS(v1, v2, v3, v4) { v1, v2, v3, v4 }
+  #elif HOTENDS > 2
+    #define ARRAY_BY_HOTENDS(v1, v2, v3, v4) { v1, v2, v3 }
+  #elif HOTENDS > 1
+    #define ARRAY_BY_HOTENDS(v1, v2, v3, v4) { v1, v2 }
+  #else
+    #define ARRAY_BY_HOTENDS(v1, v2, v3, v4) { v1 }
  #endif

+  #define ARRAY_BY_HOTENDS1(v1) ARRAY_BY_HOTENDS(v1, v1, v1, v1)
+
  /**
   * Z_DUAL_ENDSTOPS endstop reassignment
   */
@ -695,11 +715,11 @@
   * Helper Macros for heaters and extruder fan
   */
  #define WRITE_HEATER_0P(v) WRITE(HEATER_0_PIN, v)
-  #if EXTRUDERS > 1 || ENABLED(HEATERS_PARALLEL)
+  #if HOTENDS > 1 || ENABLED(HEATERS_PARALLEL)
    #define WRITE_HEATER_1(v) WRITE(HEATER_1_PIN, v)
-    #if EXTRUDERS > 2
+    #if HOTENDS > 2
      #define WRITE_HEATER_2(v) WRITE(HEATER_2_PIN, v)
-      #if EXTRUDERS > 3
+      #if HOTENDS > 3
        #define WRITE_HEATER_3(v) WRITE(HEATER_3_PIN, v)
      #endif
    #endif
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@ -356,16 +356,16 @@ static uint8_t target_extruder;
 #endif

 // Extruder offsets
-#if EXTRUDERS > 1
-  #ifndef EXTRUDER_OFFSET_X
-    #define EXTRUDER_OFFSET_X { 0 } // X offsets for each extruder
+#if HOTENDS > 1
+  #ifndef HOTEND_OFFSET_X
+    #define HOTEND_OFFSET_X { 0 } // X offsets for each extruder
  #endif
-  #ifndef EXTRUDER_OFFSET_Y
-    #define EXTRUDER_OFFSET_Y { 0 } // Y offsets for each extruder
+  #ifndef HOTEND_OFFSET_Y
+    #define HOTEND_OFFSET_Y { 0 } // Y offsets for each extruder
  #endif
-  float extruder_offset[][EXTRUDERS] = {
-    EXTRUDER_OFFSET_X,
-    EXTRUDER_OFFSET_Y
+  float hotend_offset[][HOTENDS] = {
+    HOTEND_OFFSET_X,
+    HOTEND_OFFSET_Y
    #if ENABLED(DUAL_X_CARRIAGE)
      , { 0 } // Z offsets for each extruder
    #endif
@ -1249,7 +1249,7 @@ XYZ_CONSTS_FROM_CONFIG(signed char, home_dir, HOME_DIR);
       * This allow soft recalibration of the second extruder offset position
       * without firmware reflash (through the M218 command).
       */
-      return (extruder_offset[X_AXIS][1] > 0) ? extruder_offset[X_AXIS][1] : X2_HOME_POS;
+      return (hotend_offset[X_AXIS][1] > 0) ? hotend_offset[X_AXIS][1] : X2_HOME_POS;
  }

  static int x_home_dir(int extruder) {
@ -1280,7 +1280,7 @@ static void update_software_endstops(AxisEnum axis) {

  #if ENABLED(DUAL_X_CARRIAGE)
    if (axis == X_AXIS) {
-      float dual_max_x = max(extruder_offset[X_AXIS][1], X2_MAX_POS);
+      float dual_max_x = max(hotend_offset[X_AXIS][1], X2_MAX_POS);
      if (active_extruder != 0) {
        sw_endstop_min[X_AXIS] = X2_MIN_POS + offs;
        sw_endstop_max[X_AXIS] = dual_max_x + offs;
@ -4407,8 +4407,8 @@ inline void gcode_M104() {
      SERIAL_PROTOCOLPGM(" /");
      SERIAL_PROTOCOL_F(thermalManager.degTargetBed(), 1);
    #endif
-    #if EXTRUDERS > 1
-      for (int8_t e = 0; e < EXTRUDERS; ++e) {
+    #if HOTENDS > 1
+      for (int8_t e = 0; e < HOTENDS; ++e) {
        SERIAL_PROTOCOLPGM(" T");
        SERIAL_PROTOCOL(e);
        SERIAL_PROTOCOLCHAR(':');
@ -4433,8 +4433,8 @@ inline void gcode_M104() {
    #else
      SERIAL_PROTOCOL(thermalManager.getHeaterPower(target_extruder));
    #endif
-    #if EXTRUDERS > 1
-      for (int8_t e = 0; e < EXTRUDERS; ++e) {
+    #if HOTENDS > 1
+      for (int8_t e = 0; e < HOTENDS; ++e) {
        SERIAL_PROTOCOLPGM(" @");
        SERIAL_PROTOCOL(e);
        SERIAL_PROTOCOLCHAR(':');
@ -4453,13 +4453,13 @@ inline void gcode_M104() {
        SERIAL_PROTOCOLPGM("C->");
        SERIAL_PROTOCOL_F(thermalManager.rawBedTemp() / OVERSAMPLENR, 0);
      #endif
-      for (int8_t cur_extruder = 0; cur_extruder < EXTRUDERS; ++cur_extruder) {
+      for (int8_t cur_hotend = 0; cur_hotend < HOTENDS; ++cur_hotend) {
        SERIAL_PROTOCOLPGM("  T");
-        SERIAL_PROTOCOL(cur_extruder);
+        SERIAL_PROTOCOL(cur_hotend);
        SERIAL_PROTOCOLCHAR(':');
-        SERIAL_PROTOCOL_F(thermalManager.degHotend(cur_extruder), 1);
+        SERIAL_PROTOCOL_F(thermalManager.degHotend(cur_hotend), 1);
        SERIAL_PROTOCOLPGM("C->");
-        SERIAL_PROTOCOL_F(thermalManager.rawHotendTemp(cur_extruder) / OVERSAMPLENR, 0);
+        SERIAL_PROTOCOL_F(thermalManager.rawHotendTemp(cur_hotend) / OVERSAMPLENR, 0);
      }
    #endif
  }
@ -5391,7 +5391,7 @@ inline void gcode_M206() {

 #endif // FWRETRACT

-#if EXTRUDERS > 1
+#if HOTENDS > 1

  /**
   * M218 - set hotend offset (in mm)
@ -5404,29 +5404,29 @@ inline void gcode_M206() {
  inline void gcode_M218() {
    if (get_target_extruder_from_command(218)) return;

-    if (code_seen('X')) extruder_offset[X_AXIS][target_extruder] = code_value();
-    if (code_seen('Y')) extruder_offset[Y_AXIS][target_extruder] = code_value();
+    if (code_seen('X')) hotend_offset[X_AXIS][target_extruder] = code_value();
+    if (code_seen('Y')) hotend_offset[Y_AXIS][target_extruder] = code_value();

    #if ENABLED(DUAL_X_CARRIAGE)
-      if (code_seen('Z')) extruder_offset[Z_AXIS][target_extruder] = code_value();
+      if (code_seen('Z')) hotend_offset[Z_AXIS][target_extruder] = code_value();
    #endif

    SERIAL_ECHO_START;
    SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);
-    for (int e = 0; e < EXTRUDERS; e++) {
+    for (int e = 0; e < HOTENDS; e++) {
      SERIAL_CHAR(' ');
-      SERIAL_ECHO(extruder_offset[X_AXIS][e]);
+      SERIAL_ECHO(hotend_offset[X_AXIS][e]);
      SERIAL_CHAR(',');
-      SERIAL_ECHO(extruder_offset[Y_AXIS][e]);
+      SERIAL_ECHO(hotend_offset[Y_AXIS][e]);
      #if ENABLED(DUAL_X_CARRIAGE)
        SERIAL_CHAR(',');
-        SERIAL_ECHO(extruder_offset[Z_AXIS][e]);
+        SERIAL_ECHO(hotend_offset[Z_AXIS][e]);
      #endif
    }
    SERIAL_EOL;
  }

-#endif // EXTRUDERS > 1
+#endif // HOTENDS > 1

 /**
 * M220: Set speed percentage factor, aka "Feed Rate" (M220 S95)
@ -5556,7 +5556,7 @@ inline void gcode_M226() {
    // default behaviour (omitting E parameter) is to update for extruder 0 only
    int e = code_seen('E') ? code_value() : 0; // extruder being updated

-    if (e < EXTRUDERS) { // catch bad input value
+    if (e < HOTENDS) { // catch bad input value
      if (code_seen('P')) PID_PARAM(Kp, e) = code_value();
      if (code_seen('I')) PID_PARAM(Ki, e) = scalePID_i(code_value());
      if (code_seen('D')) PID_PARAM(Kd, e) = scalePID_d(code_value());
@ -5568,10 +5568,10 @@ inline void gcode_M226() {

      thermalManager.updatePID();
      SERIAL_ECHO_START;
-      #if ENABLED(PID_PARAMS_PER_EXTRUDER)
+      #if ENABLED(PID_PARAMS_PER_HOTEND)
        SERIAL_ECHO(" e:"); // specify extruder in serial output
        SERIAL_ECHO(e);
-      #endif // PID_PARAMS_PER_EXTRUDER
+      #endif // PID_PARAMS_PER_HOTEND
      SERIAL_ECHO(" p:");
      SERIAL_ECHO(PID_PARAM(Kp, e));
      SERIAL_ECHO(" i:");
@ -5690,7 +5690,7 @@ inline void gcode_M303() {

    float temp = code_seen('S') ? code_value() : (e < 0 ? 70.0 : 150.0);

-    if (e >= 0 && e < EXTRUDERS)
+    if (e >= 0 && e < HOTENDS)
      target_extruder = e;

    KEEPALIVE_STATE(NOT_BUSY); // don't send "busy: processing" messages during autotune output
@ -6272,13 +6272,13 @@ inline void gcode_M503() {
        SERIAL_ECHO_START;
        SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);
        SERIAL_CHAR(' ');
-        SERIAL_ECHO(extruder_offset[X_AXIS][0]);
+        SERIAL_ECHO(hotend_offset[X_AXIS][0]);
        SERIAL_CHAR(',');
-        SERIAL_ECHO(extruder_offset[Y_AXIS][0]);
+        SERIAL_ECHO(hotend_offset[Y_AXIS][0]);
        SERIAL_CHAR(' ');
        SERIAL_ECHO(duplicate_extruder_x_offset);
        SERIAL_CHAR(',');
-        SERIAL_ECHOLN(extruder_offset[Y_AXIS][1]);
+        SERIAL_ECHOLN(hotend_offset[Y_AXIS][1]);
        break;
      case DXC_FULL_CONTROL_MODE:
      case DXC_AUTO_PARK_MODE:
@ -6436,7 +6436,7 @@ inline void gcode_T(uint8_t tmp_extruder) {
    #endif
  }

-  #if EXTRUDERS > 1
+  #if HOTENDS > 1
    if (tmp_extruder != active_extruder) {
      // Save current position to return to after applying extruder offset
      set_destination_to_current();
@ -6454,8 +6454,8 @@ inline void gcode_T(uint8_t tmp_extruder) {
        }

        // apply Y & Z extruder offset (x offset is already used in determining home pos)
-        current_position[Y_AXIS] -= extruder_offset[Y_AXIS][active_extruder] - extruder_offset[Y_AXIS][tmp_extruder];
-        current_position[Z_AXIS] -= extruder_offset[Z_AXIS][active_extruder] - extruder_offset[Z_AXIS][tmp_extruder];
+        current_position[Y_AXIS] -= hotend_offset[Y_AXIS][active_extruder] - hotend_offset[Y_AXIS][tmp_extruder];
+        current_position[Z_AXIS] -= hotend_offset[Z_AXIS][active_extruder] - hotend_offset[Z_AXIS][tmp_extruder];
        active_extruder = tmp_extruder;

        // This function resets the max/min values - the current position may be overwritten below.
@ -6485,11 +6485,11 @@ inline void gcode_T(uint8_t tmp_extruder) {
      #else // !DUAL_X_CARRIAGE
        #if ENABLED(AUTO_BED_LEVELING_FEATURE)
          // Offset extruder, make sure to apply the bed level rotation matrix
-          vector_3 tmp_offset_vec = vector_3(extruder_offset[X_AXIS][tmp_extruder],
-                                             extruder_offset[Y_AXIS][tmp_extruder],
+          vector_3 tmp_offset_vec = vector_3(hotend_offset[X_AXIS][tmp_extruder],
+                                             hotend_offset[Y_AXIS][tmp_extruder],
                                             0),
-                   act_offset_vec = vector_3(extruder_offset[X_AXIS][active_extruder],
-                                             extruder_offset[Y_AXIS][active_extruder],
+                   act_offset_vec = vector_3(hotend_offset[X_AXIS][active_extruder],
+                                             hotend_offset[Y_AXIS][active_extruder],
                                             0),
                   offset_vec = tmp_offset_vec - act_offset_vec;

@ -6521,7 +6521,7 @@ inline void gcode_T(uint8_t tmp_extruder) {

          // The newly-selected extruder is actually at...
          for (int i=X_AXIS; i<=Y_AXIS; i++) {
-            float diff = extruder_offset[i][tmp_extruder] - extruder_offset[i][active_extruder];
+            float diff = hotend_offset[i][tmp_extruder] - hotend_offset[i][active_extruder];
            current_position[i] += diff;
            position_shift[i] += diff; // Offset the coordinate space
            update_software_endstops((AxisEnum)i);
@ -6552,7 +6552,7 @@ inline void gcode_T(uint8_t tmp_extruder) {
      enable_solenoid_on_active_extruder();
    #endif // EXT_SOLENOID

-  #endif // EXTRUDERS > 1
+  #endif // HOTENDS > 1

  feedrate = stored_feedrate;

@ -6983,7 +6983,7 @@ void process_next_command() {
          break;
      #endif // FWRETRACT

-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        case 218: // M218 - set hotend offset (in mm), T<extruder_number> X<offset_on_X> Y<offset_on_Y>
          gcode_M218();
          break;
@ -7853,8 +7853,8 @@ void prepare_move() {
    float max_temp = 0.0;
    if (ELAPSED(millis(), next_status_led_update_ms)) {
      next_status_led_update_ms += 500; // Update every 0.5s
-      for (int8_t cur_extruder = 0; cur_extruder < EXTRUDERS; ++cur_extruder)
-        max_temp = max(max(max_temp, thermalManager.degHotend(cur_extruder)), thermalManager.degTargetHotend(cur_extruder));
+      for (int8_t cur_hotend = 0; cur_hotend < HOTENDS; ++cur_hotend)
+        max_temp = max(max(max_temp, thermalManager.degHotend(cur_hotend)), thermalManager.degTargetHotend(cur_hotend));
      #if HAS_TEMP_BED
        max_temp = max(max(max_temp, thermalManager.degTargetBed()), thermalManager.degBed());
      #endif
--- a/Marlin/SanityCheck.h
+++ b/Marlin/SanityCheck.h
@ -468,39 +468,45 @@
 /**
 * Test Heater, Temp Sensor, and Extruder Pins; Sensor Type must also be set.
 */
-#if EXTRUDERS > 3
-  #if TEMP_SENSOR_3 == 0
-    #error "TEMP_SENSOR_3 is required with 4 EXTRUDERS."
-  #elif !HAS_HEATER_3
-    #error "HEATER_3_PIN not defined for this board."
-  #elif !PIN_EXISTS(TEMP_3)
-    #error "TEMP_3_PIN not defined for this board."
-  #elif !PIN_EXISTS(E3_STEP) || !PIN_EXISTS(E3_DIR) || !PIN_EXISTS(E3_ENABLE)
-    #error "E3_STEP_PIN, E3_DIR_PIN, or E3_ENABLE_PIN not defined for this board."
+#if !HAS_HEATER_0
+  #error "HEATER_0_PIN not defined for this board."
+#elif !PIN_EXISTS(TEMP_0)
+  #error "TEMP_0_PIN not defined for this board."
+#elif !PIN_EXISTS(E0_STEP) || !PIN_EXISTS(E0_DIR) || !PIN_EXISTS(E0_ENABLE)
+  #error "E0_STEP_PIN, E0_DIR_PIN, or E0_ENABLE_PIN not defined for this board."
+#elif TEMP_SENSOR_0 == 0
+  #error "TEMP_SENSOR_0 is required."
 #endif
-#elif EXTRUDERS > 2
+
+#if HOTENDS > 1 || ENABLED(HEATERS_PARALLEL)
+  #if !HAS_HEATER_1
+    #error "HEATER_1_PIN not defined for this board."
+  #endif
+#endif
+
+#if HOTENDS > 1
+  #if TEMP_SENSOR_1 == 0
+    #error "TEMP_SENSOR_1 is required with 2 or more HOTENDS."
+  #elif !PIN_EXISTS(TEMP_1)
+    #error "TEMP_1_PIN not defined for this board."
+  #endif
+  #if HOTENDS > 2
    #if TEMP_SENSOR_2 == 0
-    #error "TEMP_SENSOR_2 is required with 3 or more EXTRUDERS."
+      #error "TEMP_SENSOR_2 is required with 3 or more HOTENDS."
    #elif !HAS_HEATER_2
      #error "HEATER_2_PIN not defined for this board."
    #elif !PIN_EXISTS(TEMP_2)
      #error "TEMP_2_PIN not defined for this board."
-  #elif !PIN_EXISTS(E2_STEP) || !PIN_EXISTS(E2_DIR) || !PIN_EXISTS(E2_ENABLE)
-    #error "E2_STEP_PIN, E2_DIR_PIN, or E2_ENABLE_PIN not defined for this board."
    #endif
-#elif EXTRUDERS > 1
-  #if TEMP_SENSOR_1 == 0
-    #error "TEMP_SENSOR_1 is required with 2 or more EXTRUDERS."
-  #elif !PIN_EXISTS(TEMP_1)
-    #error "TEMP_1_PIN not defined for this board."
-  #elif !PIN_EXISTS(E1_STEP) || !PIN_EXISTS(E1_DIR) || !PIN_EXISTS(E1_ENABLE)
-    #error "E1_STEP_PIN, E1_DIR_PIN, or E1_ENABLE_PIN not defined for this board."
+    #if HOTENDS > 3
+      #if TEMP_SENSOR_3 == 0
+        #error "TEMP_SENSOR_3 is required with 4 HOTENDS."
+      #elif !HAS_HEATER_3
+        #error "HEATER_3_PIN not defined for this board."
+      #elif !PIN_EXISTS(TEMP_3)
+        #error "TEMP_3_PIN not defined for this board."
      #endif
    #endif
-
-#if EXTRUDERS > 1 || ENABLED(HEATERS_PARALLEL)
-  #if !HAS_HEATER_1
-    #error "HEATER_1_PIN not defined for this board."
  #endif
 #endif

@ -508,14 +514,21 @@
  #error "TEMP_SENSOR_1 is required with TEMP_SENSOR_1_AS_REDUNDANT."
 #endif

-#if !HAS_HEATER_0
-  #error "HEATER_0_PIN not defined for this board."
-#elif !PIN_EXISTS(TEMP_0)
-  #error "TEMP_0_PIN not defined for this board."
-#elif !PIN_EXISTS(E0_STEP) || !PIN_EXISTS(E0_DIR) || !PIN_EXISTS(E0_ENABLE)
-  #error "E0_STEP_PIN, E0_DIR_PIN, or E0_ENABLE_PIN not defined for this board."
-#elif TEMP_SENSOR_0 == 0
-  #error "TEMP_SENSOR_0 is required."
+/**
+ * Test Extruder Pins
+ */
+#if EXTRUDERS > 3
+  #if !PIN_EXISTS(E3_STEP) || !PIN_EXISTS(E3_DIR) || !PIN_EXISTS(E3_ENABLE)
+    #error E3_STEP_PIN, E3_DIR_PIN, or E3_ENABLE_PIN not defined for this board.
+  #endif
+#elif EXTRUDERS > 2
+  #if !PIN_EXISTS(E2_STEP) || !PIN_EXISTS(E2_DIR) || !PIN_EXISTS(E2_ENABLE)
+    #error E2_STEP_PIN, E2_DIR_PIN, or E2_ENABLE_PIN not defined for this board.
+  #endif
+#elif EXTRUDERS > 1
+  #if !PIN_EXISTS(E1_STEP) || !PIN_EXISTS(E1_DIR) || !PIN_EXISTS(E1_ENABLE)
+    #error E1_STEP_PIN, E1_DIR_PIN, or E1_ENABLE_PIN not defined for this board.
+  #endif
 #endif

 /**
@ -574,6 +587,12 @@
  #error "Z_DUAL_ENDSTOPS settings are simplified. Just set Z2_USE_ENDSTOP to the endstop you want to repurpose for Z2"
 #elif defined(LANGUAGE_INCLUDE)
  #error "LANGUAGE_INCLUDE has been replaced by LCD_LANGUAGE. Please update your configuration."
+#elif defined(EXTRUDER_OFFSET_X) || defined(EXTRUDER_OFFSET_Y)
+  #error "EXTRUDER_OFFSET_[XY] is deprecated. Use HOTEND_OFFSET_[XY] instead."
+#elif defined(PID_PARAMS_PER_EXTRUDER)
+  #error "PID_PARAMS_PER_EXTRUDER is deprecated. Use PID_PARAMS_PER_HOTEND instead."
+#elif defined(EXTRUDER_WATTS)
+  #error "EXTRUDER_WATTS is deprecated. Use HOTEND_WATTS instead."
 #endif

 #endif //SANITYCHECK_H
--- a/Marlin/boards.h
+++ b/Marlin/boards.h
@ -32,17 +32,17 @@
 #define BOARD_CHEAPTRONIC       2    // Cheaptronic v1.0
 #define BOARD_SETHI             20   // Sethi 3D_1
 #define BOARD_RAMPS_OLD         3    // MEGA/RAMPS up to 1.2
-#define BOARD_RAMPS_13_EFB      33   // RAMPS 1.3 (Power outputs: Extruder, Fan, Bed)
-#define BOARD_RAMPS_13_EEB      34   // RAMPS 1.3 (Power outputs: Extruder0, Extruder1, Bed)
-#define BOARD_RAMPS_13_EFF      35   // RAMPS 1.3 (Power outputs: Extruder, Fan, Fan)
-#define BOARD_RAMPS_13_EEF      36   // RAMPS 1.3 (Power outputs: Extruder0, Extruder1, Fan)
+#define BOARD_RAMPS_13_EFB      33   // RAMPS 1.3 (Power outputs: Hotend, Fan, Bed)
+#define BOARD_RAMPS_13_EEB      34   // RAMPS 1.3 (Power outputs: Hotend0, Hotend1, Bed)
+#define BOARD_RAMPS_13_EFF      35   // RAMPS 1.3 (Power outputs: Hotend, Fan0, Fan1)
+#define BOARD_RAMPS_13_EEF      36   // RAMPS 1.3 (Power outputs: Hotend0, Hotend1, Fan)
 #define BOARD_RAMPS_13_SF       38   // RAMPS 1.3 (Power outputs: Spindle, Controller Fan)
 #define BOARD_FELIX2            37   // Felix 2.0+ Electronics Board (RAMPS like)
 #define BOARD_RIGIDBOARD        42   // Invent-A-Part RigidBoard
-#define BOARD_RAMPS_14_EFB      43   // RAMPS 1.4 (Power outputs: Extruder, Fan, Bed)
-#define BOARD_RAMPS_14_EEB      44   // RAMPS 1.4 (Power outputs: Extruder0, Extruder1, Bed)
-#define BOARD_RAMPS_14_EFF      45   // RAMPS 1.4 (Power outputs: Extruder, Fan, Fan)
-#define BOARD_RAMPS_14_EEF      46   // RAMPS 1.4 (Power outputs: Extruder0, Extruder1, Fan)
+#define BOARD_RAMPS_14_EFB      43   // RAMPS 1.4 (Power outputs: Hotend, Fan, Bed)
+#define BOARD_RAMPS_14_EEB      44   // RAMPS 1.4 (Power outputs: Hotend0, Hotend1, Bed)
+#define BOARD_RAMPS_14_EFF      45   // RAMPS 1.4 (Power outputs: Hotend, Fan0, Fan1)
+#define BOARD_RAMPS_14_EEF      46   // RAMPS 1.4 (Power outputs: Hotend0, Hotend1, Fan)
 #define BOARD_RAMPS_14_SF       48   // RAMPS 1.4 (Power outputs: Spindle, Controller Fan)
 #define BOARD_GEN6              5    // Gen6
 #define BOARD_GEN6_DELUXE       51   // Gen6 deluxe
--- a/Marlin/configuration_store.cpp
+++ b/Marlin/configuration_store.cpp
@ -246,7 +246,7 @@ void Config_StoreSettings()  {
  for (uint8_t e = 0; e < 4; e++) {

    #if ENABLED(PIDTEMP)
-      if (e < EXTRUDERS) {
+      if (e < HOTENDS) {
        EEPROM_WRITE_VAR(i, PID_PARAM(Kp, e));
        EEPROM_WRITE_VAR(i, PID_PARAM(Ki, e));
        EEPROM_WRITE_VAR(i, PID_PARAM(Kd, e));
@ -266,7 +266,7 @@ void Config_StoreSettings()  {
        for (uint8_t q = 3; q--;) EEPROM_WRITE_VAR(i, dummy); // Ki, Kd, Kc
      }

-  } // Extruders Loop
+  } // Hotends Loop

  #if DISABLED(PID_ADD_EXTRUSION_RATE)
    int lpq_len = 20;
@ -426,7 +426,7 @@ void Config_RetrieveSettings() {
    #if ENABLED(PIDTEMP)
      for (uint8_t e = 0; e < 4; e++) { // 4 = max extruders currently supported by Marlin
        EEPROM_READ_VAR(i, dummy); // Kp
-        if (e < EXTRUDERS && dummy != DUMMY_PID_VALUE) {
+        if (e < HOTENDS && dummy != DUMMY_PID_VALUE) {
          // do not need to scale PID values as the values in EEPROM are already scaled
          PID_PARAM(Kp, e) = dummy;
          EEPROM_READ_VAR(i, PID_PARAM(Ki, e));
@ -584,8 +584,8 @@ void Config_ResetDefault() {
  #endif

  #if ENABLED(PIDTEMP)
-    #if ENABLED(PID_PARAMS_PER_EXTRUDER)
-      for (uint8_t e = 0; e < EXTRUDERS; e++)
+    #if ENABLED(PID_PARAMS_PER_HOTEND)
+      for (uint8_t e = 0; e < HOTENDS; e++)
    #else
      int e = 0; UNUSED(e); // only need to write once
    #endif
@ -801,9 +801,9 @@ void Config_PrintSettings(bool forReplay) {
      SERIAL_ECHOLNPGM("PID settings:");
    }
    #if ENABLED(PIDTEMP)
-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        if (forReplay) {
-          for (uint8_t i = 0; i < EXTRUDERS; i++) {
+          for (uint8_t i = 0; i < HOTENDS; i++) {
            CONFIG_ECHO_START;
            SERIAL_ECHOPAIR("  M301 E", i);
            SERIAL_ECHOPAIR(" P", PID_PARAM(Kp, i));
@ -817,8 +817,8 @@ void Config_PrintSettings(bool forReplay) {
          }
        }
        else
-      #endif // EXTRUDERS > 1
-      // !forReplay || EXTRUDERS == 1
+      #endif // HOTENDS > 1
+      // !forReplay || HOTENDS == 1
      {
        CONFIG_ECHO_START;
        SERIAL_ECHOPAIR("  M301 P", PID_PARAM(Kp, 0)); // for compatibility with hosts, only echo values for E0
--- a/Marlin/dogm_bitmaps.h
+++ b/Marlin/dogm_bitmaps.h
@ -110,7 +110,7 @@
 // be displayed.

 #if HAS_TEMP_BED
-  #if EXTRUDERS == 1
+  #if HOTENDS == 1
    #define STATUS_SCREENWIDTH     115 //Width in pixels
    #define STATUS_SCREENHEIGHT     19 //Height in pixels
    #define STATUS_SCREENBYTEWIDTH  15 //Width in bytes
@ -160,7 +160,7 @@
      0x1E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xFF, 0xFF, 0x80, 0x7F, 0xFF, 0xE0,
      0x0C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x00
    };
-  #elif EXTRUDERS == 2
+  #elif HOTENDS == 2
    #define STATUS_SCREENWIDTH     115 //Width in pixels
    #define STATUS_SCREENHEIGHT     19 //Height in pixels
    #define STATUS_SCREENBYTEWIDTH  15 //Width in bytes
@ -262,7 +262,7 @@
    };
  #endif // Extruders
 #else
-  #if EXTRUDERS == 1
+  #if HOTENDS == 1
    #define STATUS_SCREENWIDTH     115 //Width in pixels
    #define STATUS_SCREENHEIGHT     19 //Height in pixels
    #define STATUS_SCREENBYTEWIDTH  15 //Width in bytes
@ -312,7 +312,7 @@
      0x1E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7F, 0xFF, 0xE0,
      0x0C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    };
-  #elif EXTRUDERS == 2
+  #elif HOTENDS == 2
    #define STATUS_SCREENWIDTH     115 //Width in pixels
    #define STATUS_SCREENHEIGHT     19 //Height in pixels
    #define STATUS_SCREENBYTEWIDTH  15 //Width in bytes
--- a/Marlin/dogm_lcd_implementation.h
+++ b/Marlin/dogm_lcd_implementation.h
@ -370,10 +370,10 @@ static void lcd_implementation_status_screen() {
  #endif

  // Extruders
-  for (int i = 0; i < EXTRUDERS; i++) _draw_heater_status(5 + i * 25, i);
+  for (int i = 0; i < HOTENDS; i++) _draw_heater_status(5 + i * 25, i);

  // Heated bed
-  #if EXTRUDERS < 4 && HAS_TEMP_BED
+  #if HOTENDS < 4 && HAS_TEMP_BED
    _draw_heater_status(81, -1);
  #endif

--- a/Marlin/example_configurations/Felix/Configuration.h
+++ b/Marlin/example_configurations/Felix/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/Felix/Configuration_adv.h
+++ b/Marlin/example_configurations/Felix/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/Felix/DUAL/Configuration.h
+++ b/Marlin/example_configurations/Felix/DUAL/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/Hephestos/Configuration.h
+++ b/Marlin/example_configurations/Hephestos/Configuration.h
@ -129,8 +129,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -227,7 +227,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -244,7 +244,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/Hephestos/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/Hephestos_2/Configuration.h
+++ b/Marlin/example_configurations/Hephestos_2/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 250  // If the temperature difference between the target temperature and the actual temperature
                                    // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
+++ b/Marlin/example_configurations/Hephestos_2/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/K8200/Configuration.h
+++ b/Marlin/example_configurations/K8200/Configuration.h
@ -133,8 +133,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -231,7 +231,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -248,7 +248,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/K8200/Configuration_adv.h
+++ b/Marlin/example_configurations/K8200/Configuration_adv.h
@ -243,7 +243,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
+++ b/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/RigidBot/Configuration.h
+++ b/Marlin/example_configurations/RigidBot/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-#define EXTRUDER_OFFSET_X {0.0, 36.00} // (in mm) for each extruder, offset of the hotend on the X axis
-#define EXTRUDER_OFFSET_Y {0.0, 0.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+#define HOTEND_OFFSET_X {0.0, 36.00} // (in mm) for each extruder, offset of the hotend on the X axis
+#define HOTEND_OFFSET_Y {0.0, 0.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/RigidBot/Configuration_adv.h
+++ b/Marlin/example_configurations/RigidBot/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/SCARA/Configuration.h
+++ b/Marlin/example_configurations/SCARA/Configuration.h
@ -151,8 +151,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -249,7 +249,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-#define EXTRUDER_WATTS (2*2/5.9)       // P=U^2/R
+#define HOTEND_WATTS (2*2/5.9)       // P=U^2/R
 #define BED_WATTS (5.45*5.45/2.2)    // P=U^2/R

 //===========================================================================
@ -266,7 +266,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 20 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/SCARA/Configuration_adv.h
+++ b/Marlin/example_configurations/SCARA/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/TAZ4/Configuration.h
+++ b/Marlin/example_configurations/TAZ4/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 16 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/TAZ4/Configuration_adv.h
+++ b/Marlin/example_configurations/TAZ4/Configuration_adv.h
@ -245,7 +245,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/WITBOX/Configuration.h
+++ b/Marlin/example_configurations/WITBOX/Configuration.h
@ -129,8 +129,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -227,7 +227,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -244,7 +244,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/WITBOX/Configuration_adv.h
+++ b/Marlin/example_configurations/WITBOX/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/adafruit/ST7565/Configuration.h
+++ b/Marlin/example_configurations/adafruit/ST7565/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/biv2.5/Configuration.h
+++ b/Marlin/example_configurations/delta/biv2.5/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/biv2.5/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/delta/generic/Configuration.h
+++ b/Marlin/example_configurations/delta/generic/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/generic/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/generic/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration.h
@ -132,8 +132,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -230,7 +230,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -247,7 +247,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 50 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h
@ -242,7 +242,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/delta/kossel_xl/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_xl/Configuration.h
@ -119,8 +119,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -217,7 +217,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -234,7 +234,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
+++ b/Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/makibox/Configuration.h
+++ b/Marlin/example_configurations/makibox/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/makibox/Configuration_adv.h
+++ b/Marlin/example_configurations/makibox/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration.h
@ -126,8 +126,8 @@
 // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
 // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
 // For the other hotends it is their distance from the extruder 0 hotend.
-//#define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
-//#define EXTRUDER_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis
+//#define HOTEND_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
+//#define HOTEND_OFFSET_Y {0.0, 5.00}  // (in mm) for each extruder, offset of the hotend on the Y axis

 //// The following define selects which power supply you have. Please choose the one that matches your setup
 // 1 = ATX
@ -224,7 +224,7 @@
 #define BED_MAXTEMP 150

 // If you want the M105 heater power reported in watts, define the BED_WATTS, and (shared for all extruders) EXTRUDER_WATTS
-//#define EXTRUDER_WATTS (12.0*12.0/6.7) // P=U^2/R
+//#define HOTEND_WATTS (12.0*12.0/6.7) // P=U^2/R
 //#define BED_WATTS (12.0*12.0/1.1)    // P=U^2/R

 //===========================================================================
@ -241,7 +241,7 @@
  //#define PID_DEBUG // Sends debug data to the serial port.
  //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
  //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
-  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+  //#define PID_PARAMS_PER_HOTEND // Uses separate PID parameters for each extruder (useful for mismatched extruders)
                                  // Set/get with gcode: M301 E[extruder number, 0-2]
  #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                  // is more than PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h
@ -237,7 +237,7 @@
  #define X2_MAX_POS 353    // set maximum to the distance between toolheads when both heads are homed
  #define X2_HOME_DIR 1     // the second X-carriage always homes to the maximum endstop position
  #define X2_HOME_POS X2_MAX_POS // default home position is the maximum carriage position
-      // However: In this mode the EXTRUDER_OFFSET_X value for the second extruder provides a software
+      // However: In this mode the HOTEND_OFFSET_X value for the second extruder provides a software
      // override for X2_HOME_POS. This also allow recalibration of the distance between the two endstops
      // without modifying the firmware (through the "M218 T1 X???" command).
      // Remember: you should set the second extruder x-offset to 0 in your slicer.
--- a/Marlin/pins.h
+++ b/Marlin/pins.h
@ -243,20 +243,38 @@
 #define marlinAnalogInputToDigitalPin(p) ((p) == -1 ? -1 : (p) + 0xA0)

 // List of pins which to ignore when asked to change by gcode, 0 and 1 are RX and TX, do not mess with those!
-#define _E0_PINS E0_STEP_PIN, E0_DIR_PIN, E0_ENABLE_PIN, E0_MS1_PIN, E0_MS2_PIN, HEATER_0_PIN, EXTRUDER_0_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_0_PIN),
+#define _E0_PINS E0_STEP_PIN, E0_DIR_PIN, E0_ENABLE_PIN, E0_MS1_PIN, E0_MS2_PIN,
 #define _E1_PINS
 #define _E2_PINS
 #define _E3_PINS

 #if EXTRUDERS > 1
  #undef _E1_PINS
-  #define _E1_PINS E1_STEP_PIN, E1_DIR_PIN, E1_ENABLE_PIN, HEATER_1_PIN, E1_MS1_PIN, E1_MS2_PIN, EXTRUDER_1_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_1_PIN),
+  #define _E1_PINS E1_STEP_PIN, E1_DIR_PIN, E1_ENABLE_PIN, E1_MS1_PIN, E1_MS2_PIN,
  #if EXTRUDERS > 2
    #undef _E2_PINS
-    #define _E2_PINS E2_STEP_PIN, E2_DIR_PIN, E2_ENABLE_PIN, HEATER_2_PIN, EXTRUDER_2_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_2_PIN),
+    #define _E2_PINS E2_STEP_PIN, E2_DIR_PIN, E2_ENABLE_PIN,
    #if EXTRUDERS > 3
      #undef _E3_PINS
-      #define _E3_PINS E3_STEP_PIN, E3_DIR_PIN, E3_ENABLE_PIN, HEATER_3_PIN, EXTRUDER_3_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_3_PIN),
+      #define _E3_PINS E3_STEP_PIN, E3_DIR_PIN, E3_ENABLE_PIN,
+    #endif
+  #endif
+#endif
+
+#define _H0_PINS HEATER_0_PIN, EXTRUDER_0_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_0_PIN),
+#define _H1_PINS
+#define _H2_PINS
+#define _H3_PINS
+
+#if HOTENDS > 1
+  #undef _H1_PINS
+  #define _H1_PINS HEATER_1_PIN, EXTRUDER_1_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_1_PIN),
+  #if HOTENDS > 2
+    #undef _H2_PINS
+    #define _H2_PINS HEATER_2_PIN, EXTRUDER_2_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_2_PIN),
+    #if HOTENDS > 3
+      #undef _H3_PINS
+      #define _H3_PINS HEATER_3_PIN, EXTRUDER_3_AUTO_FAN_PIN, marlinAnalogInputToDigitalPin(TEMP_3_PIN),
    #endif
  #endif
 #endif
@ -383,6 +401,7 @@
    Z_STEP_PIN, Z_DIR_PIN, Z_ENABLE_PIN, Z_MIN_PIN, Z_MAX_PIN, Z_MIN_PROBE_PIN, \
    PS_ON_PIN, HEATER_BED_PIN, FAN_PIN, FAN1_PIN, FAN2_PIN, CONTROLLERFAN_PIN, \
    _E0_PINS _E1_PINS _E2_PINS _E3_PINS BED_PINS \
+    _H0_PINS _H1_PINS _H2_PINS _H3_PINS \
    _X2_PINS _Y2_PINS _Z2_PINS \
    X_MS1_PIN, X_MS2_PIN, Y_MS1_PIN, Y_MS2_PIN, Z_MS1_PIN, Z_MS2_PIN \
  }
--- a/Marlin/pins_MEGACONTROLLER.h
+++ b/Marlin/pins_MEGACONTROLLER.h
@ -28,7 +28,7 @@
  #error "Oops!  Make sure you have 'Arduino Mega' selected from the 'Tools -> Boards' menu."
 #endif

-#if EXTRUDERS > 2
+#if EXTRUDERS > 2 || HOTENDS > 2
  #error "Mega Controller supports up to 2 extruders. Comment this line to keep going."
 #endif

--- a/Marlin/pins_RAMPS_14.h
+++ b/Marlin/pins_RAMPS_14.h
@ -25,16 +25,16 @@
 *
 * Applies to the following boards:
 *
- *  RAMPS_14_EFB (Extruder, Fan, Bed)
- *  RAMPS_14_EEB (Extruder, Extruder, Bed)
- *  RAMPS_14_EFF (Extruder, Fan, Fan)
- *  RAMPS_14_EEF (Extruder, Extruder, Fan)
+ *  RAMPS_14_EFB (Hotend, Fan, Bed)
+ *  RAMPS_14_EEB (Hotend0, Hotend1, Bed)
+ *  RAMPS_14_EFF (Hotend, Fan0, Fan1)
+ *  RAMPS_14_EEF (Hotend0, Hotend1, Fan)
 *  RAMPS_14_SF  (Spindle, Controller Fan)
 *
- *  RAMPS_13_EFB (Extruder, Fan, Bed)
- *  RAMPS_13_EEB (Extruder, Extruder, Bed)
- *  RAMPS_13_EFF (Extruder, Fan, Fan)
- *  RAMPS_13_EEF (Extruder, Extruder, Fan)
+ *  RAMPS_13_EFB (Hotend, Fan, Bed)
+ *  RAMPS_13_EEB (Hotend0, Hotend1, Bed)
+ *  RAMPS_13_EFF (Hotend, Fan0, Fan1)
+ *  RAMPS_13_EEF (Hotend0, Hotend1, Fan)
 *  RAMPS_13_SF  (Spindle, Controller Fan)
 *
 *  Other pins_MYBOARD.h files may override these defaults
--- a/Marlin/pins_RUMBA.h
+++ b/Marlin/pins_RUMBA.h
@ -28,7 +28,7 @@
  #error "Oops!  Make sure you have 'Arduino Mega' selected from the 'Tools -> Boards' menu."
 #endif

-#if EXTRUDERS > 3
+#if EXTRUDERS > 3 || HOTENDS > 3
  #error "RUMBA supports up to 3 extruders. Comment this line to keep going."
 #endif

--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@ -42,17 +42,17 @@
  static void* heater_ttbl_map[2] = {(void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE };
  static uint8_t heater_ttbllen_map[2] = { HEATER_0_TEMPTABLE_LEN, HEATER_1_TEMPTABLE_LEN };
 #else
-  static void* heater_ttbl_map[EXTRUDERS] = ARRAY_BY_EXTRUDERS((void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE, (void*)HEATER_2_TEMPTABLE, (void*)HEATER_3_TEMPTABLE);
-  static uint8_t heater_ttbllen_map[EXTRUDERS] = ARRAY_BY_EXTRUDERS(HEATER_0_TEMPTABLE_LEN, HEATER_1_TEMPTABLE_LEN, HEATER_2_TEMPTABLE_LEN, HEATER_3_TEMPTABLE_LEN);
+  static void* heater_ttbl_map[HOTENDS] = ARRAY_BY_HOTENDS((void*)HEATER_0_TEMPTABLE, (void*)HEATER_1_TEMPTABLE, (void*)HEATER_2_TEMPTABLE, (void*)HEATER_3_TEMPTABLE);
+  static uint8_t heater_ttbllen_map[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_TEMPTABLE_LEN, HEATER_1_TEMPTABLE_LEN, HEATER_2_TEMPTABLE_LEN, HEATER_3_TEMPTABLE_LEN);
 #endif

 Temperature thermalManager;

 // public:

-int Temperature::current_temperature_raw[EXTRUDERS] = { 0 };
-float Temperature::current_temperature[EXTRUDERS] = { 0.0 };
-int Temperature::target_temperature[EXTRUDERS] = { 0 };
+int Temperature::current_temperature_raw[HOTENDS] = { 0 };
+float Temperature::current_temperature[HOTENDS] = { 0.0 };
+int Temperature::target_temperature[HOTENDS] = { 0 };

 int Temperature::current_temperature_bed_raw = 0;
 float Temperature::current_temperature_bed = 0.0;
@ -69,12 +69,12 @@ unsigned char Temperature::soft_pwm_bed;
 #endif

 #if ENABLED(PIDTEMP)
-  #if ENABLED(PID_PARAMS_PER_EXTRUDER)
-    float Temperature::Kp[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(DEFAULT_Kp),
-          Temperature::Ki[EXTRUDERS] = ARRAY_BY_EXTRUDERS1((DEFAULT_Ki) * (PID_dT)),
-          Temperature::Kd[EXTRUDERS] = ARRAY_BY_EXTRUDERS1((DEFAULT_Kd) / (PID_dT));
+  #if ENABLED(PID_PARAMS_PER_HOTEND)
+    float Temperature::Kp[HOTENDS] = ARRAY_BY_HOTENDS1(DEFAULT_Kp),
+          Temperature::Ki[HOTENDS] = ARRAY_BY_HOTENDS1((DEFAULT_Ki) * (PID_dT)),
+          Temperature::Kd[HOTENDS] = ARRAY_BY_HOTENDS1((DEFAULT_Kd) / (PID_dT));
    #if ENABLED(PID_ADD_EXTRUSION_RATE)
-      float Temperature::Kc[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(DEFAULT_Kc);
+      float Temperature::Kc[HOTENDS] = ARRAY_BY_HOTENDS1(DEFAULT_Kc);
    #endif
  #else
    float Temperature::Kp = DEFAULT_Kp,
@ -97,8 +97,8 @@ unsigned char Temperature::soft_pwm_bed;
 #endif

 #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_TEMP_PERIOD > 0
-  int Temperature::watch_target_temp[EXTRUDERS] = { 0 };
-  millis_t Temperature::watch_heater_next_ms[EXTRUDERS] = { 0 };
+  int Temperature::watch_target_temp[HOTENDS] = { 0 };
+  millis_t Temperature::watch_heater_next_ms[HOTENDS] = { 0 };
 #endif

 #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_BED_TEMP_PERIOD > 0
@ -120,23 +120,23 @@ unsigned char Temperature::soft_pwm_bed;
 volatile bool Temperature::temp_meas_ready = false;

 #if ENABLED(PIDTEMP)
-  float Temperature::temp_iState[EXTRUDERS] = { 0 };
-  float Temperature::temp_dState[EXTRUDERS] = { 0 };
-  float Temperature::pTerm[EXTRUDERS];
-  float Temperature::iTerm[EXTRUDERS];
-  float Temperature::dTerm[EXTRUDERS];
+  float Temperature::temp_iState[HOTENDS] = { 0 };
+  float Temperature::temp_dState[HOTENDS] = { 0 };
+  float Temperature::pTerm[HOTENDS];
+  float Temperature::iTerm[HOTENDS];
+  float Temperature::dTerm[HOTENDS];

  #if ENABLED(PID_ADD_EXTRUSION_RATE)
-    float Temperature::cTerm[EXTRUDERS];
-    long Temperature::last_position[EXTRUDERS];
+    float Temperature::cTerm[HOTENDS];
+    long Temperature::last_position[HOTENDS];
    long Temperature::lpq[LPQ_MAX_LEN];
    int Temperature::lpq_ptr = 0;
  #endif

-  float Temperature::pid_error[EXTRUDERS];
-  float Temperature::temp_iState_min[EXTRUDERS];
-  float Temperature::temp_iState_max[EXTRUDERS];
-  bool Temperature::pid_reset[EXTRUDERS];
+  float Temperature::pid_error[HOTENDS];
+  float Temperature::temp_iState_min[HOTENDS];
+  float Temperature::temp_iState_max[HOTENDS];
+  bool Temperature::pid_reset[HOTENDS];
 #endif

 #if ENABLED(PIDTEMPBED)
@ -156,10 +156,10 @@ unsigned long Temperature::raw_temp_value[4] = { 0 };
 unsigned long Temperature::raw_temp_bed_value = 0;

 // Init min and max temp with extreme values to prevent false errors during startup
-int Temperature::minttemp_raw[EXTRUDERS] = ARRAY_BY_EXTRUDERS(HEATER_0_RAW_LO_TEMP , HEATER_1_RAW_LO_TEMP , HEATER_2_RAW_LO_TEMP, HEATER_3_RAW_LO_TEMP);
-int Temperature::maxttemp_raw[EXTRUDERS] = ARRAY_BY_EXTRUDERS(HEATER_0_RAW_HI_TEMP , HEATER_1_RAW_HI_TEMP , HEATER_2_RAW_HI_TEMP, HEATER_3_RAW_HI_TEMP);
-int Temperature::minttemp[EXTRUDERS] = { 0 };
-int Temperature::maxttemp[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(16383);
+int Temperature::minttemp_raw[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_RAW_LO_TEMP , HEATER_1_RAW_LO_TEMP , HEATER_2_RAW_LO_TEMP, HEATER_3_RAW_LO_TEMP);
+int Temperature::maxttemp_raw[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_RAW_HI_TEMP , HEATER_1_RAW_HI_TEMP , HEATER_2_RAW_HI_TEMP, HEATER_3_RAW_HI_TEMP);
+int Temperature::minttemp[HOTENDS] = { 0 };
+int Temperature::maxttemp[HOTENDS] = ARRAY_BY_HOTENDS1(16383);

 #ifdef BED_MINTEMP
  int Temperature::bed_minttemp_raw = HEATER_BED_RAW_LO_TEMP;
@ -177,7 +177,7 @@ int Temperature::maxttemp[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(16383);
  millis_t Temperature::next_auto_fan_check_ms;
 #endif

-unsigned char Temperature::soft_pwm[EXTRUDERS];
+unsigned char Temperature::soft_pwm[HOTENDS];

 #if ENABLED(FAN_SOFT_PWM)
  unsigned char Temperature::soft_pwm_fan[FAN_COUNT];
@ -189,7 +189,7 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];

 #if HAS_PID_HEATING

-  void Temperature::PID_autotune(float temp, int extruder, int ncycles, bool set_result/*=false*/) {
+  void Temperature::PID_autotune(float temp, int hotend, int ncycles, bool set_result/*=false*/) {
    float input = 0.0;
    int cycles = 0;
    bool heating = true;
@ -208,12 +208,12 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];

    if (false
      #if ENABLED(PIDTEMP)
-         || extruder >= EXTRUDERS
+         || hotend >= HOTENDS
      #else
-         || extruder >= 0
+         || hotend >= 0
      #endif
      #if DISABLED(PIDTEMPBED)
-         || extruder < 0
+         || hotend < 0
      #endif
    ) {
      SERIAL_ECHOLN(MSG_PID_BAD_EXTRUDER_NUM);
@ -225,12 +225,12 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
    disable_all_heaters(); // switch off all heaters.

    #if HAS_PID_FOR_BOTH
-      if (extruder < 0)
+      if (hotend < 0)
        soft_pwm_bed = bias = d = (MAX_BED_POWER) / 2;
      else
-        soft_pwm[extruder] = bias = d = (PID_MAX) / 2;
+        soft_pwm[hotend] = bias = d = (PID_MAX) / 2;
    #elif ENABLED(PIDTEMP)
-      soft_pwm[extruder] = bias = d = (PID_MAX) / 2;
+      soft_pwm[hotend] = bias = d = (PID_MAX) / 2;
    #else
      soft_pwm_bed = bias = d = (MAX_BED_POWER) / 2;
    #endif
@ -245,9 +245,9 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];

        input =
          #if HAS_PID_FOR_BOTH
-            extruder < 0 ? current_temperature_bed : current_temperature[extruder]
+            hotend < 0 ? current_temperature_bed : current_temperature[hotend]
          #elif ENABLED(PIDTEMP)
-            current_temperature[extruder]
+            current_temperature[hotend]
          #else
            current_temperature_bed
          #endif
@ -267,12 +267,12 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
          if (ELAPSED(ms, t2 + 5000UL)) {
            heating = false;
            #if HAS_PID_FOR_BOTH
-              if (extruder < 0)
+              if (hotend < 0)
                soft_pwm_bed = (bias - d) >> 1;
              else
-                soft_pwm[extruder] = (bias - d) >> 1;
+                soft_pwm[hotend] = (bias - d) >> 1;
            #elif ENABLED(PIDTEMP)
-              soft_pwm[extruder] = (bias - d) >> 1;
+              soft_pwm[hotend] = (bias - d) >> 1;
            #elif ENABLED(PIDTEMPBED)
              soft_pwm_bed = (bias - d) >> 1;
            #endif
@ -290,7 +290,7 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
            if (cycles > 0) {
              long max_pow =
                #if HAS_PID_FOR_BOTH
-                  extruder < 0 ? MAX_BED_POWER : PID_MAX
+                  hotend < 0 ? MAX_BED_POWER : PID_MAX
                #elif ENABLED(PIDTEMP)
                  PID_MAX
                #else
@ -336,12 +336,12 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
              }
            }
            #if HAS_PID_FOR_BOTH
-              if (extruder < 0)
+              if (hotend < 0)
                soft_pwm_bed = (bias + d) >> 1;
              else
-                soft_pwm[extruder] = (bias + d) >> 1;
+                soft_pwm[hotend] = (bias + d) >> 1;
            #elif ENABLED(PIDTEMP)
-              soft_pwm[extruder] = (bias + d) >> 1;
+              soft_pwm[hotend] = (bias + d) >> 1;
            #else
              soft_pwm_bed = (bias + d) >> 1;
            #endif
@ -373,7 +373,7 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
        SERIAL_PROTOCOLLNPGM(MSG_PID_AUTOTUNE_FINISHED);

        #if HAS_PID_FOR_BOTH
-          const char* estring = extruder < 0 ? "bed" : "";
+          const char* estring = hotend < 0 ? "bed" : "";
          SERIAL_PROTOCOLPGM("#define  DEFAULT_"); SERIAL_PROTOCOL(estring); SERIAL_PROTOCOLPGM("Kp "); SERIAL_PROTOCOLLN(workKp);
          SERIAL_PROTOCOLPGM("#define  DEFAULT_"); SERIAL_PROTOCOL(estring); SERIAL_PROTOCOLPGM("Ki "); SERIAL_PROTOCOLLN(workKi);
          SERIAL_PROTOCOLPGM("#define  DEFAULT_"); SERIAL_PROTOCOL(estring); SERIAL_PROTOCOLPGM("Kd "); SERIAL_PROTOCOLLN(workKd);
@ -394,15 +394,15 @@ unsigned char Temperature::soft_pwm[EXTRUDERS];
          updatePID()

        #define _SET_EXTRUDER_PID() \
-          PID_PARAM(Kp, extruder) = workKp; \
-          PID_PARAM(Ki, extruder) = scalePID_i(workKi); \
-          PID_PARAM(Kd, extruder) = scalePID_d(workKd); \
+          PID_PARAM(Kp, hotend) = workKp; \
+          PID_PARAM(Ki, hotend) = scalePID_i(workKi); \
+          PID_PARAM(Kd, hotend) = scalePID_d(workKd); \
          updatePID()

        // Use the result? (As with "M303 U1")
        if (set_result) {
          #if HAS_PID_FOR_BOTH
-            if (extruder < 0) {
+            if (hotend < 0) {
              _SET_BED_PID();
            }
            else {
@ -430,7 +430,7 @@ Temperature::Temperature() { }

 void Temperature::updatePID() {
  #if ENABLED(PIDTEMP)
-    for (int e = 0; e < EXTRUDERS; e++) {
+    for (int e = 0; e < HOTENDS; e++) {
      temp_iState_max[e] = (PID_INTEGRAL_DRIVE_MAX) / PID_PARAM(Ki, e);
      #if ENABLED(PID_ADD_EXTRUSION_RATE)
        last_position[e] = 0;
@ -459,7 +459,7 @@ int Temperature::getHeaterPower(int heater) {
      EXTRUDER_3_AUTO_FAN_PIN == EXTRUDER_2_AUTO_FAN_PIN ? 2 : 3
    };
    uint8_t fanState = 0;
-    for (int f = 0; f <= EXTRUDERS; f++) {
+    for (int f = 0; f <= HOTENDS; f++) {
      if (current_temperature[f] > EXTRUDER_AUTO_FAN_TEMPERATURE)
        SBI(fanState, fanBit[f]);
    }
@ -665,8 +665,8 @@ void Temperature::manage_heater() {
    millis_t ms = millis();
  #endif

-  // Loop through all extruders
-  for (int e = 0; e < EXTRUDERS; e++) {
+  // Loop through all hotends
+  for (int e = 0; e < HOTENDS; e++) {

    #if ENABLED(THERMAL_PROTECTION_HOTENDS)
      thermal_runaway_protection(&thermal_runaway_state_machine[e], &thermal_runaway_timer[e], current_temperature[e], target_temperature[e], e, THERMAL_PROTECTION_PERIOD, THERMAL_PROTECTION_HYSTERESIS);
@ -719,7 +719,7 @@ void Temperature::manage_heater() {
      }
    #endif

-  } // Extruders Loop
+  } // Hotends Loop

  #if HAS_AUTO_FAN
    if (ELAPSED(ms, next_auto_fan_check_ms)) { // only need to check fan state very infrequently
@ -790,9 +790,9 @@ void Temperature::manage_heater() {
 // For hot end temperature measurement.
 float Temperature::analog2temp(int raw, uint8_t e) {
  #if ENABLED(TEMP_SENSOR_1_AS_REDUNDANT)
-    if (e > EXTRUDERS)
+    if (e > HOTENDS)
  #else
-    if (e >= EXTRUDERS)
+    if (e >= HOTENDS)
  #endif
    {
      SERIAL_ERROR_START;
@ -873,7 +873,7 @@ void Temperature::updateTemperaturesFromRawValues() {
  #if ENABLED(HEATER_0_USES_MAX6675)
    current_temperature_raw[0] = read_max6675();
  #endif
-  for (uint8_t e = 0; e < EXTRUDERS; e++) {
+  for (uint8_t e = 0; e < HOTENDS; e++) {
    current_temperature[e] = Temperature::analog2temp(current_temperature_raw[e], e);
  }
  current_temperature_bed = Temperature::analog2tempBed(current_temperature_bed_raw);
@ -926,8 +926,8 @@ void Temperature::init() {
    MCUCR = _BV(JTD);
  #endif

-  // Finish init of mult extruder arrays
-  for (int e = 0; e < EXTRUDERS; e++) {
+  // Finish init of mult hotend arrays
+  for (int e = 0; e < HOTENDS; e++) {
    // populate with the first value
    maxttemp[e] = maxttemp[0];
    #if ENABLED(PIDTEMP)
@ -1083,30 +1083,30 @@ void Temperature::init() {
  #ifdef HEATER_0_MAXTEMP
    TEMP_MAX_ROUTINE(0);
  #endif
-  #if EXTRUDERS > 1
+  #if HOTENDS > 1
    #ifdef HEATER_1_MINTEMP
      TEMP_MIN_ROUTINE(1);
    #endif
    #ifdef HEATER_1_MAXTEMP
      TEMP_MAX_ROUTINE(1);
    #endif
-    #if EXTRUDERS > 2
+    #if HOTENDS > 2
      #ifdef HEATER_2_MINTEMP
        TEMP_MIN_ROUTINE(2);
      #endif
      #ifdef HEATER_2_MAXTEMP
        TEMP_MAX_ROUTINE(2);
      #endif
-      #if EXTRUDERS > 3
+      #if HOTENDS > 3
        #ifdef HEATER_3_MINTEMP
          TEMP_MIN_ROUTINE(3);
        #endif
        #ifdef HEATER_3_MAXTEMP
          TEMP_MAX_ROUTINE(3);
        #endif
-      #endif // EXTRUDERS > 3
-    #endif // EXTRUDERS > 2
-  #endif // EXTRUDERS > 1
+      #endif // HOTENDS > 3
+    #endif // HOTENDS > 2
+  #endif // HOTENDS > 1

  #ifdef BED_MINTEMP
    while(analog2tempBed(bed_minttemp_raw) < BED_MINTEMP) {
@ -1163,8 +1163,8 @@ void Temperature::init() {
 #if ENABLED(THERMAL_PROTECTION_HOTENDS) || HAS_THERMALLY_PROTECTED_BED

  #if ENABLED(THERMAL_PROTECTION_HOTENDS)
-    Temperature::TRState Temperature::thermal_runaway_state_machine[EXTRUDERS] = { TRInactive };
-    millis_t Temperature::thermal_runaway_timer[EXTRUDERS] = { 0 };
+    Temperature::TRState Temperature::thermal_runaway_state_machine[HOTENDS] = { TRInactive };
+    millis_t Temperature::thermal_runaway_timer[HOTENDS] = { 0 };
  #endif

  #if HAS_THERMALLY_PROTECTED_BED
@ -1174,7 +1174,7 @@ void Temperature::init() {

  void Temperature::thermal_runaway_protection(Temperature::TRState* state, millis_t* timer, float temperature, float target_temperature, int heater_id, int period_seconds, int hysteresis_degc) {

-    static float tr_target_temperature[EXTRUDERS + 1] = { 0.0 };
+    static float tr_target_temperature[HOTENDS + 1] = { 0.0 };

    /**
        SERIAL_ECHO_START;
@ -1187,7 +1187,7 @@ void Temperature::init() {
        SERIAL_EOL;
    */

-    int heater_index = heater_id >= 0 ? heater_id : EXTRUDERS;
+    int heater_index = heater_id >= 0 ? heater_id : HOTENDS;

    // If the target temperature changes, restart
    if (tr_target_temperature[heater_index] != target_temperature) {
@ -1218,7 +1218,7 @@ void Temperature::init() {
 #endif // THERMAL_PROTECTION_HOTENDS || THERMAL_PROTECTION_BED

 void Temperature::disable_all_heaters() {
-  for (int i = 0; i < EXTRUDERS; i++) setTargetHotend(0, i);
+  for (int i = 0; i < HOTENDS; i++) setTargetHotend(0, i);
  setTargetBed(0);

  // If all heaters go down then for sure our print job has stopped
@ -1236,15 +1236,15 @@ void Temperature::disable_all_heaters() {
    WRITE_HEATER_0P(LOW); // Should HEATERS_PARALLEL apply here? Then change to DISABLE_HEATER(0)
  #endif

-  #if EXTRUDERS > 1 && HAS_TEMP_1
+  #if HOTENDS > 1 && HAS_TEMP_1
    DISABLE_HEATER(1);
  #endif

-  #if EXTRUDERS > 2 && HAS_TEMP_2
+  #if HOTENDS > 2 && HAS_TEMP_2
    DISABLE_HEATER(2);
  #endif

-  #if EXTRUDERS > 3 && HAS_TEMP_3
+  #if HOTENDS > 3 && HAS_TEMP_3
    DISABLE_HEATER(3);
  #endif

@ -1390,11 +1390,11 @@ void Temperature::isr() {

  // Statics per heater
  ISR_STATICS(0);
-  #if (EXTRUDERS > 1) || ENABLED(HEATERS_PARALLEL)
+  #if (HOTENDS > 1) || ENABLED(HEATERS_PARALLEL)
    ISR_STATICS(1);
-    #if EXTRUDERS > 2
+    #if HOTENDS > 2
      ISR_STATICS(2);
-      #if EXTRUDERS > 3
+      #if HOTENDS > 3
        ISR_STATICS(3);
      #endif
    #endif
@ -1418,13 +1418,13 @@ void Temperature::isr() {
      }
      else WRITE_HEATER_0P(0); // If HEATERS_PARALLEL should apply, change to WRITE_HEATER_0

-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        soft_pwm_1 = soft_pwm[1];
        WRITE_HEATER_1(soft_pwm_1 > 0 ? 1 : 0);
-        #if EXTRUDERS > 2
+        #if HOTENDS > 2
          soft_pwm_2 = soft_pwm[2];
          WRITE_HEATER_2(soft_pwm_2 > 0 ? 1 : 0);
-          #if EXTRUDERS > 3
+          #if HOTENDS > 3
            soft_pwm_3 = soft_pwm[3];
            WRITE_HEATER_3(soft_pwm_3 > 0 ? 1 : 0);
          #endif
@ -1453,11 +1453,11 @@ void Temperature::isr() {
    }

    if (soft_pwm_0 < pwm_count) WRITE_HEATER_0(0);
-    #if EXTRUDERS > 1
+    #if HOTENDS > 1
      if (soft_pwm_1 < pwm_count) WRITE_HEATER_1(0);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        if (soft_pwm_2 < pwm_count) WRITE_HEATER_2(0);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          if (soft_pwm_3 < pwm_count) WRITE_HEATER_3(0);
        #endif
      #endif
@ -1524,11 +1524,11 @@ void Temperature::isr() {
    if (slow_pwm_count == 0) {

      SLOW_PWM_ROUTINE(0); // EXTRUDER 0
-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        SLOW_PWM_ROUTINE(1); // EXTRUDER 1
-        #if EXTRUDERS > 2
+        #if HOTENDS > 2
          SLOW_PWM_ROUTINE(2); // EXTRUDER 2
-          #if EXTRUDERS > 3
+          #if HOTENDS > 3
            SLOW_PWM_ROUTINE(3); // EXTRUDER 3
          #endif
        #endif
@ -1540,11 +1540,11 @@ void Temperature::isr() {
    } // slow_pwm_count == 0

    PWM_OFF_ROUTINE(0); // EXTRUDER 0
-    #if EXTRUDERS > 1
+    #if HOTENDS > 1
      PWM_OFF_ROUTINE(1); // EXTRUDER 1
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        PWM_OFF_ROUTINE(2); // EXTRUDER 2
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          PWM_OFF_ROUTINE(3); // EXTRUDER 3
        #endif
      #endif
@ -1589,11 +1589,11 @@ void Temperature::isr() {

      // EXTRUDER 0
      if (state_timer_heater_0 > 0) state_timer_heater_0--;
-      #if EXTRUDERS > 1    // EXTRUDER 1
+      #if HOTENDS > 1    // EXTRUDER 1
        if (state_timer_heater_1 > 0) state_timer_heater_1--;
-        #if EXTRUDERS > 2    // EXTRUDER 2
+        #if HOTENDS > 2    // EXTRUDER 2
          if (state_timer_heater_2 > 0) state_timer_heater_2--;
-          #if EXTRUDERS > 3    // EXTRUDER 3
+          #if HOTENDS > 3    // EXTRUDER 3
            if (state_timer_heater_3 > 0) state_timer_heater_3--;
          #endif
        #endif
@ -1736,7 +1736,7 @@ void Temperature::isr() {
      if (minttemp_raw[0] GE0 current_temperature_raw[0]) min_temp_error(0);
    #endif

-    #if HAS_TEMP_1 && EXTRUDERS > 1
+    #if HAS_TEMP_1 && HOTENDS > 1
      #if HEATER_1_RAW_LO_TEMP > HEATER_1_RAW_HI_TEMP
        #define GE1 <=
      #else
@ -1746,7 +1746,7 @@ void Temperature::isr() {
      if (minttemp_raw[1] GE1 current_temperature_raw[1]) min_temp_error(1);
    #endif // TEMP_SENSOR_1

-    #if HAS_TEMP_2 && EXTRUDERS > 2
+    #if HAS_TEMP_2 && HOTENDS > 2
      #if HEATER_2_RAW_LO_TEMP > HEATER_2_RAW_HI_TEMP
        #define GE2 <=
      #else
@ -1756,7 +1756,7 @@ void Temperature::isr() {
      if (minttemp_raw[2] GE2 current_temperature_raw[2]) min_temp_error(2);
    #endif // TEMP_SENSOR_2

-    #if HAS_TEMP_3 && EXTRUDERS > 3
+    #if HAS_TEMP_3 && HOTENDS > 3
      #if HEATER_3_RAW_LO_TEMP > HEATER_3_RAW_HI_TEMP
        #define GE3 <=
      #else
--- a/Marlin/temperature.h
+++ b/Marlin/temperature.h
@ -42,9 +42,9 @@ class Temperature {

  public:

-    static int current_temperature_raw[EXTRUDERS];
-    static float current_temperature[EXTRUDERS];
-    static int target_temperature[EXTRUDERS];
+    static int current_temperature_raw[HOTENDS];
+    static float current_temperature[HOTENDS];
+    static int target_temperature[HOTENDS];

    static int current_temperature_bed_raw;
    static float current_temperature_bed;
@ -66,11 +66,11 @@ class Temperature {

    #if ENABLED(PIDTEMP)

-      #if ENABLED(PID_PARAMS_PER_EXTRUDER)
+      #if ENABLED(PID_PARAMS_PER_HOTEND)

-        static float Kp[EXTRUDERS], Ki[EXTRUDERS], Kd[EXTRUDERS];
+        static float Kp[HOTENDS], Ki[HOTENDS], Kd[HOTENDS];
        #if ENABLED(PID_ADD_EXTRUSION_RATE)
-          static float Kc[EXTRUDERS];
+          static float Kc[HOTENDS];
        #endif
        #define PID_PARAM(param, e) Temperature::param[e]

@ -82,7 +82,7 @@ class Temperature {
        #endif
        #define PID_PARAM(param, e) Temperature::param

-      #endif // PID_PARAMS_PER_EXTRUDER
+      #endif // PID_PARAMS_PER_HOTEND

      // Apply the scale factors to the PID values
      #define scalePID_i(i)   ( (i) * PID_dT )
@ -101,8 +101,8 @@ class Temperature {
    #endif

    #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_TEMP_PERIOD > 0
-      static int watch_target_temp[EXTRUDERS];
-      static millis_t watch_heater_next_ms[EXTRUDERS];
+      static int watch_target_temp[HOTENDS];
+      static millis_t watch_heater_next_ms[HOTENDS];
    #endif

    #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_BED_TEMP_PERIOD > 0
@ -127,23 +127,23 @@ class Temperature {
    static volatile bool temp_meas_ready;

    #if ENABLED(PIDTEMP)
-      static float temp_iState[EXTRUDERS];
-      static float temp_dState[EXTRUDERS];
-      static float pTerm[EXTRUDERS];
-      static float iTerm[EXTRUDERS];
-      static float dTerm[EXTRUDERS];
+      static float temp_iState[HOTENDS];
+      static float temp_dState[HOTENDS];
+      static float pTerm[HOTENDS];
+      static float iTerm[HOTENDS];
+      static float dTerm[HOTENDS];

      #if ENABLED(PID_ADD_EXTRUSION_RATE)
-        static float cTerm[EXTRUDERS];
-        static long last_position[EXTRUDERS];
+        static float cTerm[HOTENDS];
+        static long last_position[HOTENDS];
        static long lpq[LPQ_MAX_LEN];
        static int lpq_ptr;
      #endif

-      static float pid_error[EXTRUDERS];
-      static float temp_iState_min[EXTRUDERS];
-      static float temp_iState_max[EXTRUDERS];
-      static bool pid_reset[EXTRUDERS];
+      static float pid_error[HOTENDS];
+      static float temp_iState_min[HOTENDS];
+      static float temp_iState_max[HOTENDS];
+      static bool pid_reset[HOTENDS];
    #endif

    #if ENABLED(PIDTEMPBED)
@ -163,10 +163,10 @@ class Temperature {
    static unsigned long raw_temp_bed_value;

    // Init min and max temp with extreme values to prevent false errors during startup
-    static int minttemp_raw[EXTRUDERS];
-    static int maxttemp_raw[EXTRUDERS];
-    static int minttemp[EXTRUDERS];
-    static int maxttemp[EXTRUDERS];
+    static int minttemp_raw[HOTENDS];
+    static int maxttemp_raw[HOTENDS];
+    static int minttemp[HOTENDS];
+    static int maxttemp[HOTENDS];

    #ifdef BED_MINTEMP
      static int bed_minttemp_raw;
@ -184,7 +184,7 @@ class Temperature {
      static millis_t next_auto_fan_check_ms;
    #endif

-    static unsigned char soft_pwm[EXTRUDERS];
+    static unsigned char soft_pwm[HOTENDS];

    #if ENABLED(FAN_SOFT_PWM)
      static unsigned char soft_pwm_fan[FAN_COUNT];
@ -230,15 +230,36 @@ class Temperature {
    //inline so that there is no performance decrease.
    //deg=degreeCelsius

-    static float degHotend(uint8_t extruder) { return current_temperature[extruder]; }
+    #if HOTENDS == 1
+      #define HOTEND_ARG 0
+    #else
+      #define HOTEND_ARG hotend
+    #endif
+
+    static float degHotend(uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      return current_temperature[HOTEND_ARG];
+    }
    static float degBed() { return current_temperature_bed; }

    #if ENABLED(SHOW_TEMP_ADC_VALUES)
-    static float rawHotendTemp(uint8_t extruder) { return current_temperature_raw[extruder]; }
+    static float rawHotendTemp(uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      return current_temperature_raw[HOTEND_ARG];
+    }
    static float rawBedTemp() { return current_temperature_bed_raw; }
    #endif

-    static float degTargetHotend(uint8_t extruder) { return target_temperature[extruder]; }
+    static float degTargetHotend(uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      return target_temperature[HOTEND_ARG];
+    }
    static float degTargetBed() { return target_temperature_bed; }

    #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_TEMP_PERIOD > 0
@ -249,10 +270,13 @@ class Temperature {
      static void start_watching_bed();
    #endif

-    static void setTargetHotend(const float& celsius, uint8_t extruder) {
-      target_temperature[extruder] = celsius;
+    static void setTargetHotend(const float& celsius, uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      target_temperature[HOTEND_ARG] = celsius;
      #if ENABLED(THERMAL_PROTECTION_HOTENDS) && WATCH_TEMP_PERIOD > 0
-        start_watching_heater(extruder);
+        start_watching_heater(HOTEND_ARG);
      #endif
    }

@ -263,10 +287,20 @@ class Temperature {
      #endif
    }

-    static bool isHeatingHotend(uint8_t extruder) { return target_temperature[extruder] > current_temperature[extruder]; }
+    static bool isHeatingHotend(uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      return target_temperature[HOTEND_ARG] > current_temperature[HOTEND_ARG];
+    }
    static bool isHeatingBed() { return target_temperature_bed > current_temperature_bed; }

-    static bool isCoolingHotend(uint8_t extruder) { return target_temperature[extruder] < current_temperature[extruder]; }
+    static bool isCoolingHotend(uint8_t hotend) {
+      #if HOTENDS == 1
+        UNUSED(hotend);
+      #endif
+      return target_temperature[HOTEND_ARG] < current_temperature[HOTEND_ARG];
+    }
    static bool isCoolingBed() { return target_temperature_bed < current_temperature_bed; }

    /**
@ -283,7 +317,7 @@ class Temperature {
     * Perform auto-tuning for hotend or bed in response to M303
     */
    #if HAS_PID_HEATING
-      static void PID_autotune(float temp, int extruder, int ncycles, bool set_result=false);
+      static void PID_autotune(float temp, int hotend, int ncycles, bool set_result=false);
    #endif

    /**
@ -362,8 +396,8 @@ class Temperature {
      static void thermal_runaway_protection(TRState* state, millis_t* timer, float temperature, float target_temperature, int heater_id, int period_seconds, int hysteresis_degc);

      #if ENABLED(THERMAL_PROTECTION_HOTENDS)
-        static TRState thermal_runaway_state_machine[EXTRUDERS];
-        static millis_t thermal_runaway_timer[EXTRUDERS];
+        static TRState thermal_runaway_state_machine[HOTENDS];
+        static millis_t thermal_runaway_timer[HOTENDS];
      #endif

      #if HAS_THERMALLY_PROTECTED_BED
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@ -593,28 +593,28 @@ void lcd_set_home_offsets() {
  #if TEMP_SENSOR_0 != 0
    void watch_temp_callback_E0() { thermalManager.start_watching_heater(0); }
  #endif
-  #if EXTRUDERS > 1 && TEMP_SENSOR_1 != 0
+  #if HOTENDS > 1 && TEMP_SENSOR_1 != 0
    void watch_temp_callback_E1() { thermalManager.start_watching_heater(1); }
-  #endif // EXTRUDERS > 1
-  #if EXTRUDERS > 2 && TEMP_SENSOR_2 != 0
+  #endif // HOTENDS > 1
+  #if HOTENDS > 2 && TEMP_SENSOR_2 != 0
    void watch_temp_callback_E2() { thermalManager.start_watching_heater(2); }
-  #endif // EXTRUDERS > 2
-  #if EXTRUDERS > 3 && TEMP_SENSOR_3 != 0
+  #endif // HOTENDS > 2
+  #if HOTENDS > 3 && TEMP_SENSOR_3 != 0
    void watch_temp_callback_E3() { thermalManager.start_watching_heater(3); }
-  #endif // EXTRUDERS > 3
+  #endif // HOTENDS > 3
 #else
  #if TEMP_SENSOR_0 != 0
    void watch_temp_callback_E0() {}
  #endif
-  #if EXTRUDERS > 1 && TEMP_SENSOR_1 != 0
+  #if HOTENDS > 1 && TEMP_SENSOR_1 != 0
    void watch_temp_callback_E1() {}
-  #endif // EXTRUDERS > 1
-  #if EXTRUDERS > 2 && TEMP_SENSOR_2 != 0
+  #endif // HOTENDS > 1
+  #if HOTENDS > 2 && TEMP_SENSOR_2 != 0
    void watch_temp_callback_E2() {}
-  #endif // EXTRUDERS > 2
-  #if EXTRUDERS > 3 && TEMP_SENSOR_3 != 0
+  #endif // HOTENDS > 2
+  #if HOTENDS > 3 && TEMP_SENSOR_3 != 0
    void watch_temp_callback_E3() {}
-  #endif // EXTRUDERS > 3
+  #endif // HOTENDS > 3
 #endif

 #if ENABLED(THERMAL_PROTECTION_BED) && WATCH_BED_TEMP_PERIOD > 0
@ -654,28 +654,28 @@ static void lcd_tune_menu() {
  // Nozzle:
  // Nozzle [1-4]:
  //
-  #if EXTRUDERS == 1
+  #if HOTENDS == 1
    #if TEMP_SENSOR_0 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE, &thermalManager.target_temperature[0], 0, HEATER_0_MAXTEMP - 15, watch_temp_callback_E0);
    #endif
-  #else //EXTRUDERS > 1
+  #else //HOTENDS > 1
    #if TEMP_SENSOR_0 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N1, &thermalManager.target_temperature[0], 0, HEATER_0_MAXTEMP - 15, watch_temp_callback_E0);
    #endif
    #if TEMP_SENSOR_1 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N2, &thermalManager.target_temperature[1], 0, HEATER_1_MAXTEMP - 15, watch_temp_callback_E1);
    #endif
-    #if EXTRUDERS > 2
+    #if HOTENDS > 2
      #if TEMP_SENSOR_2 != 0
        MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N3, &thermalManager.target_temperature[2], 0, HEATER_2_MAXTEMP - 15, watch_temp_callback_E2);
      #endif
-      #if EXTRUDERS > 3
+      #if HOTENDS > 3
        #if TEMP_SENSOR_3 != 0
          MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N4, &thermalManager.target_temperature[3], 0, HEATER_3_MAXTEMP - 15, watch_temp_callback_E3);
        #endif
-      #endif // EXTRUDERS > 3
-    #endif // EXTRUDERS > 2
-  #endif // EXTRUDERS > 1
+      #endif // HOTENDS > 3
+    #endif // HOTENDS > 2
+  #endif // HOTENDS > 1

  //
  // Bed:
@ -777,24 +777,24 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
  void lcd_preheat_abs0() { _lcd_preheat(0, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
 #endif

-#if EXTRUDERS > 1
+#if HOTENDS > 1
  void lcd_preheat_pla1() { _lcd_preheat(1, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
  void lcd_preheat_abs1() { _lcd_preheat(1, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
-  #if EXTRUDERS > 2
+  #if HOTENDS > 2
    void lcd_preheat_pla2() { _lcd_preheat(2, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
    void lcd_preheat_abs2() { _lcd_preheat(2, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
-    #if EXTRUDERS > 3
+    #if HOTENDS > 3
      void lcd_preheat_pla3() { _lcd_preheat(3, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
      void lcd_preheat_abs3() { _lcd_preheat(3, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
    #endif
  #endif

  void lcd_preheat_pla0123() {
-    #if EXTRUDERS > 1
+    #if HOTENDS > 1
      thermalManager.setTargetHotend(plaPreheatHotendTemp, 1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        thermalManager.setTargetHotend(plaPreheatHotendTemp, 2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          thermalManager.setTargetHotend(plaPreheatHotendTemp, 3);
        #endif
      #endif
@ -802,11 +802,11 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
    lcd_preheat_pla0();
  }
  void lcd_preheat_abs0123() {
-    #if EXTRUDERS > 1
+    #if HOTENDS > 1
      thermalManager.setTargetHotend(absPreheatHotendTemp, 1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        thermalManager.setTargetHotend(absPreheatHotendTemp, 2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          thermalManager.setTargetHotend(absPreheatHotendTemp, 3);
        #endif
      #endif
@ -814,7 +814,7 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
    lcd_preheat_abs0();
  }

-#endif // EXTRUDERS > 1
+#endif // HOTENDS > 1

 #if TEMP_SENSOR_BED != 0
  void lcd_preheat_pla_bedonly() { _lcd_preheat(0, 0, plaPreheatHPBTemp, plaPreheatFanSpeed); }
@ -826,14 +826,14 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
  static void lcd_preheat_pla_menu() {
    START_MENU();
    MENU_ITEM(back, MSG_PREPARE);
-    #if EXTRUDERS == 1
+    #if HOTENDS == 1
      MENU_ITEM(function, MSG_PREHEAT_PLA, lcd_preheat_pla0);
    #else
      MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H1, lcd_preheat_pla0);
      MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H2, lcd_preheat_pla1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H3, lcd_preheat_pla2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H4, lcd_preheat_pla3);
        #endif
      #endif
@ -848,14 +848,14 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
  static void lcd_preheat_abs_menu() {
    START_MENU();
    MENU_ITEM(back, MSG_PREPARE);
-    #if EXTRUDERS == 1
+    #if HOTENDS == 1
      MENU_ITEM(function, MSG_PREHEAT_ABS, lcd_preheat_abs0);
    #else
      MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H1, lcd_preheat_abs0);
      MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H2, lcd_preheat_abs1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H3, lcd_preheat_abs2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H4, lcd_preheat_abs3);
        #endif
      #endif
@ -1380,8 +1380,8 @@ static void lcd_control_menu() {
 #if ENABLED(PID_AUTOTUNE_MENU)

  #if ENABLED(PIDTEMP)
-    int autotune_temp[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(150);
-    const int heater_maxtemp[EXTRUDERS] = ARRAY_BY_EXTRUDERS(HEATER_0_MAXTEMP, HEATER_1_MAXTEMP, HEATER_2_MAXTEMP, HEATER_3_MAXTEMP);
+    int autotune_temp[HOTENDS] = ARRAY_BY_HOTENDS1(150);
+    const int heater_maxtemp[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_MAXTEMP, HEATER_1_MAXTEMP, HEATER_2_MAXTEMP, HEATER_3_MAXTEMP);
  #endif

  #if ENABLED(PIDTEMPBED)
@ -1409,14 +1409,14 @@ static void lcd_control_menu() {
  // Helpers for editing PID Ki & Kd values
  // grab the PID value out of the temp variable; scale it; then update the PID driver
  void copy_and_scalePID_i(int e) {
-    #if DISABLED(PID_PARAMS_PER_EXTRUDER)
+    #if DISABLED(PID_PARAMS_PER_HOTEND)
      UNUSED(e);
    #endif
    PID_PARAM(Ki, e) = scalePID_i(raw_Ki);
    thermalManager.updatePID();
  }
  void copy_and_scalePID_d(int e) {
-    #if DISABLED(PID_PARAMS_PER_EXTRUDER)
+    #if DISABLED(PID_PARAMS_PER_HOTEND)
      UNUSED(e);
    #endif
    PID_PARAM(Kd, e) = scalePID_d(raw_Kd);
@ -1435,17 +1435,17 @@ static void lcd_control_menu() {
  #endif

  _PIDTEMP_FUNCTIONS(0);
-  #if ENABLED(PID_PARAMS_PER_EXTRUDER)
-    #if EXTRUDERS > 1
+  #if ENABLED(PID_PARAMS_PER_HOTEND)
+    #if HOTENDS > 1
      _PIDTEMP_FUNCTIONS(1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        _PIDTEMP_FUNCTIONS(2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          _PIDTEMP_FUNCTIONS(3);
-        #endif //EXTRUDERS > 3
-      #endif //EXTRUDERS > 2
-    #endif //EXTRUDERS > 1
-  #endif //PID_PARAMS_PER_EXTRUDER
+        #endif //HOTENDS > 3
+      #endif //HOTENDS > 2
+    #endif //HOTENDS > 1
+  #endif //PID_PARAMS_PER_HOTEND

 #endif //PIDTEMP

@ -1466,28 +1466,28 @@ static void lcd_control_temperature_menu() {
  // Nozzle:
  // Nozzle [1-4]:
  //
-  #if EXTRUDERS == 1
+  #if HOTENDS == 1
    #if TEMP_SENSOR_0 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE, &thermalManager.target_temperature[0], 0, HEATER_0_MAXTEMP - 15, watch_temp_callback_E0);
    #endif
-  #else //EXTRUDERS > 1
+  #else //HOTENDS > 1
    #if TEMP_SENSOR_0 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N1, &thermalManager.target_temperature[0], 0, HEATER_0_MAXTEMP - 15, watch_temp_callback_E0);
    #endif
    #if TEMP_SENSOR_1 != 0
      MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N2, &thermalManager.target_temperature[1], 0, HEATER_1_MAXTEMP - 15, watch_temp_callback_E1);
    #endif
-    #if EXTRUDERS > 2
+    #if HOTENDS > 2
      #if TEMP_SENSOR_2 != 0
        MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N3, &thermalManager.target_temperature[2], 0, HEATER_2_MAXTEMP - 15, watch_temp_callback_E2);
      #endif
-      #if EXTRUDERS > 3
+      #if HOTENDS > 3
        #if TEMP_SENSOR_3 != 0
          MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(int3, MSG_NOZZLE MSG_N4, &thermalManager.target_temperature[3], 0, HEATER_3_MAXTEMP - 15, watch_temp_callback_E3);
        #endif
-      #endif // EXTRUDERS > 3
-    #endif // EXTRUDERS > 2
-  #endif // EXTRUDERS > 1
+      #endif // HOTENDS > 3
+    #endif // HOTENDS > 2
+  #endif // HOTENDS > 1

  //
  // Bed:
@ -1558,18 +1558,18 @@ static void lcd_control_temperature_menu() {
      #define PID_MENU_ITEMS(ELABEL, eindex) _PID_MENU_ITEMS(ELABEL, eindex)
    #endif

-    #if ENABLED(PID_PARAMS_PER_EXTRUDER) && EXTRUDERS > 1
+    #if ENABLED(PID_PARAMS_PER_HOTEND) && HOTENDS > 1
      PID_MENU_ITEMS(MSG_E1, 0);
      PID_MENU_ITEMS(MSG_E2, 1);
-      #if EXTRUDERS > 2
+      #if HOTENDS > 2
        PID_MENU_ITEMS(MSG_E3, 2);
-        #if EXTRUDERS > 3
+        #if HOTENDS > 3
          PID_MENU_ITEMS(MSG_E4, 3);
-        #endif //EXTRUDERS > 3
-      #endif //EXTRUDERS > 2
-    #else //!PID_PARAMS_PER_EXTRUDER || EXTRUDERS == 1
+        #endif //HOTENDS > 3
+      #endif //HOTENDS > 2
+    #else //!PID_PARAMS_PER_HOTEND || HOTENDS == 1
      PID_MENU_ITEMS("", 0);
-    #endif //!PID_PARAMS_PER_EXTRUDER || EXTRUDERS == 1
+    #endif //!PID_PARAMS_PER_HOTEND || HOTENDS == 1

  #endif //PIDTEMP

--- a/Marlin/ultralcd_implementation_hitachi_HD44780.h
+++ b/Marlin/ultralcd_implementation_hitachi_HD44780.h
@ -638,10 +638,10 @@ static void lcd_implementation_status_screen() {
    //
    // Hotend 1 or Bed Temperature
    //
-    #if EXTRUDERS > 1 || TEMP_SENSOR_BED != 0
+    #if HOTENDS > 1 || TEMP_SENSOR_BED != 0

      lcd.setCursor(8, 0);
-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        lcd.print(LCD_STR_THERMOMETER[0]);
        LCD_TEMP_ONLY(thermalManager.degHotend(1), thermalManager.degTargetHotend(1));
      #else
@ -649,7 +649,7 @@ static void lcd_implementation_status_screen() {
        LCD_TEMP_ONLY(thermalManager.degBed(), thermalManager.degTargetBed());
      #endif

-    #endif // EXTRUDERS > 1 || TEMP_SENSOR_BED != 0
+    #endif // HOTENDS > 1 || TEMP_SENSOR_BED != 0

  #else // LCD_WIDTH >= 20

@ -661,15 +661,15 @@ static void lcd_implementation_status_screen() {
    //
    // Hotend 1 or Bed Temperature
    //
-    #if EXTRUDERS > 1 || TEMP_SENSOR_BED != 0
+    #if HOTENDS > 1 || TEMP_SENSOR_BED != 0
      lcd.setCursor(10, 0);
-      #if EXTRUDERS > 1
+      #if HOTENDS > 1
        LCD_TEMP(thermalManager.degHotend(1), thermalManager.degTargetHotend(1), LCD_STR_THERMOMETER[0]);
      #else
        LCD_TEMP(thermalManager.degBed(), thermalManager.degTargetBed(), LCD_STR_BEDTEMP[0]);
      #endif

-    #endif  // EXTRUDERS > 1 || TEMP_SENSOR_BED != 0
+    #endif  // HOTENDS > 1 || TEMP_SENSOR_BED != 0

  #endif // LCD_WIDTH >= 20

@ -697,7 +697,7 @@ static void lcd_implementation_status_screen() {

      lcd.setCursor(0, 1);

-      #if EXTRUDERS > 1 && TEMP_SENSOR_BED != 0
+      #if HOTENDS > 1 && TEMP_SENSOR_BED != 0

        // If we both have a 2nd extruder and a heated bed,
        // show the heated bed temp on the left,
@ -717,7 +717,7 @@ static void lcd_implementation_status_screen() {
        _draw_axis_label(Y_AXIS, PSTR(MSG_Y), blink);
        lcd.print(ftostr4sign(current_position[Y_AXIS]));

-      #endif // EXTRUDERS > 1 || TEMP_SENSOR_BED != 0
+      #endif // HOTENDS > 1 || TEMP_SENSOR_BED != 0

    #endif // LCD_WIDTH >= 20

@ -943,7 +943,7 @@ void lcd_implementation_drawedit(const char* pstr, const char* value=NULL) {
      ) leds |= LED_C;
    #endif // FAN_COUNT > 0

-    #if EXTRUDERS > 1
+    #if HOTENDS > 1
      if (thermalManager.degTargetHotend(1) > 0) leds |= LED_C;
    #endif