🔧 Permit extrude without hotend (MarlinFirmware#25709)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Author: ellensp

Marlin/src/gcode/gcode.cpp

@@ -581,7 +581,7 @@ void GcodeSuite::process_parsed_command(const bool no_ok/*=false*/) {
         case 102: M102(); break;                                  // M102: Configure Bed Distance Sensor
       #endif
 
-      #if HAS_EXTRUDERS
+      #if HAS_HOTEND
         case 104: M104(); break;                                  // M104: Set hot end temperature
         case 109: M109(); break;                                  // M109: Wait for hotend temperature to reach target
       #endif

Marlin/src/gcode/gcode.h

@@ -716,7 +716,7 @@ class GcodeSuite {
     static void M102_report(const bool forReplay=true);
   #endif
 
-  #if HAS_EXTRUDERS
+  #if HAS_HOTEND
     static void M104_M109(const bool isM109);
     FORCE_INLINE static void M104() { M104_M109(false); }
     FORCE_INLINE static void M109() { M104_M109(true); }

Marlin/src/gcode/temp/M104_M109.cpp

@@ -28,7 +28,7 @@
 
 #include "../../inc/MarlinConfigPre.h"
 
-#if HAS_EXTRUDERS
+#if HAS_HOTEND
 
 #include "../gcode.h"
 #include "../../module/temperature.h"
@@ -135,4 +135,4 @@ void GcodeSuite::M104_M109(const bool isM109) {
     (void)thermalManager.wait_for_hotend(target_extruder, no_wait_for_cooling);
 }
 
-#endif // EXTRUDERS
+#endif // HAS_HOTEND

Marlin/src/inc/Conditionals_LCD.h

@@ -624,8 +624,6 @@
   #undef MIXING_EXTRUDER
   #undef HOTEND_IDLE_TIMEOUT
   #undef DISABLE_E
-  #undef THERMAL_PROTECTION_HOTENDS
-  #undef PREVENT_COLD_EXTRUSION
   #undef PREVENT_LENGTHY_EXTRUDE
   #undef FILAMENT_RUNOUT_SENSOR
   #undef FILAMENT_RUNOUT_DISTANCE_MM
@@ -657,9 +655,6 @@
   #else
     #define E_STEPPERS    1
   #endif
-  #if !HAS_SWITCHING_NOZZLE
-    #define HOTENDS       E_STEPPERS
-  #endif
 
 #elif ENABLED(MIXING_EXTRUDER)      // Multiple feeds are mixed proportionally
 
@@ -691,23 +686,53 @@
   #define SINGLENOZZLE
 #endif
 
-#if EITHER(SINGLENOZZLE, MIXING_EXTRUDER)         // One hotend, one thermistor, no XY offset
-  #undef HOTENDS
-  #define HOTENDS       1
-  #undef HOTEND_OFFSET_X
-  #undef HOTEND_OFFSET_Y
-#endif
-
-#ifndef HOTENDS
-  #define HOTENDS EXTRUDERS
-#endif
+// Default E steppers / manual motion is one per extruder
 #ifndef E_STEPPERS
   #define E_STEPPERS EXTRUDERS
 #endif
 #ifndef E_MANUAL
   #define E_MANUAL EXTRUDERS
 #endif
 
+// Number of hotends...
+#if EITHER(SINGLENOZZLE, MIXING_EXTRUDER)               // Only one for singlenozzle or mixing extruder
+  #define HOTENDS 1
+#elif HAS_SWITCHING_EXTRUDER && !HAS_SWITCHING_NOZZLE   // One for each pair of abstract "extruders"
+  #define HOTENDS E_STEPPERS
+#elif TEMP_SENSOR_0
+  #define HOTENDS EXTRUDERS                             // One per extruder if at least one heater exists
+#else
+  #define HOTENDS 0                                     // A machine with no hotends at all can still extrude
+#endif
+
+// More than one hotend...
+#if HOTENDS > 1
+  #define HAS_MULTI_HOTEND 1
+  #define HAS_HOTEND_OFFSET 1
+  #ifndef HOTEND_OFFSET_X
+    #define HOTEND_OFFSET_X { 0 } // X offsets for each extruder
+  #endif
+  #ifndef HOTEND_OFFSET_Y
+    #define HOTEND_OFFSET_Y { 0 } // Y offsets for each extruder
+  #endif
+  #ifndef HOTEND_OFFSET_Z
+    #define HOTEND_OFFSET_Z { 0 } // Z offsets for each extruder
+  #endif
+#else
+  #undef HOTEND_OFFSET_X
+  #undef HOTEND_OFFSET_Y
+  #undef HOTEND_OFFSET_Z
+#endif
+
+// At least one hotend...
+#if HOTENDS
+  #define HAS_HOTEND 1
+  #ifndef HOTEND_OVERSHOOT
+    #define HOTEND_OVERSHOOT 15
+  #endif
+#endif
+
+// Clean up E-stepper-based settings...
 #if E_STEPPERS <= 7
   #undef INVERT_E7_DIR
   #undef E7_DRIVER_TYPE
@@ -1037,19 +1062,6 @@
   #define E_INDEX_N(E) 0
 #endif
 
-#if HOTENDS
-  #define HAS_HOTEND 1
-  #ifndef HOTEND_OVERSHOOT
-    #define HOTEND_OVERSHOOT 15
-  #endif
-  #if HOTENDS > 1
-    #define HAS_MULTI_HOTEND 1
-    #define HAS_HOTEND_OFFSET 1
-  #endif
-#else
-  #undef PID_PARAMS_PER_HOTEND
-#endif
-
 // Helper macros for extruder and hotend arrays
 #define _EXTRUDER_LOOP(E) for (int8_t E = 0; E < EXTRUDERS; E++)
 #define EXTRUDER_LOOP() _EXTRUDER_LOOP(e)
@@ -1061,21 +1073,6 @@
 #define ARRAY_BY_HOTENDS(V...) ARRAY_N(HOTENDS, V)
 #define ARRAY_BY_HOTENDS1(v1) ARRAY_N_1(HOTENDS, v1)
 
-/**
- * Default hotend offsets, if not defined
- */
-#if HAS_HOTEND_OFFSET
-  #ifndef HOTEND_OFFSET_X
-    #define HOTEND_OFFSET_X { 0 } // X offsets for each extruder
-  #endif
-  #ifndef HOTEND_OFFSET_Y
-    #define HOTEND_OFFSET_Y { 0 } // Y offsets for each extruder
-  #endif
-  #ifndef HOTEND_OFFSET_Z
-    #define HOTEND_OFFSET_Z { 0 } // Z offsets for each extruder
-  #endif
-#endif
-
 /**
  * Disable unused SINGLENOZZLE sub-options
  */