✨ PROBING_TOOL (#24411)

Marlin/Configuration.h

@@ -1552,6 +1552,12 @@
  */
 #define NOZZLE_TO_PROBE_OFFSET { 10, 10, 0 }
 
+// Enable and set to use a specific tool for probing. Disable to allow any tool.
+#define PROBING_TOOL 0
+#ifdef PROBING_TOOL
+  //#define PROBE_TOOLCHANGE_NO_MOVE  // Suppress motion on probe tool-change
+#endif
+
 // Most probes should stay away from the edges of the bed, but
 // with NOZZLE_AS_PROBE this can be negative for a wider probing area.
 #define PROBING_MARGIN 10

Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp

@@ -306,16 +306,13 @@ void unified_bed_leveling::G29() {
 
   const uint8_t p_val = parser.byteval('P');
   const bool may_move = p_val == 1 || p_val == 2 || p_val == 4 || parser.seen_test('J');
-  #if HAS_MULTI_HOTEND
-    const uint8_t old_tool_index = active_extruder;
-  #endif
 
   // Check for commands that require the printer to be homed
   if (may_move) {
     planner.synchronize();
     // Send 'N' to force homing before G29 (internal only)
     if (axes_should_home() || parser.seen_test('N')) gcode.home_all_axes();
-    TERN_(HAS_MULTI_HOTEND, if (active_extruder != 0) tool_change(0, true));
+    probe.use_probing_tool();
 
     // Position bed horizontally and Z probe vertically.
     #if HAS_SAFE_BED_LEVELING
@@ -696,7 +693,7 @@ void unified_bed_leveling::G29() {
     UNUSED(probe_deployed);
   #endif
 
-  TERN_(HAS_MULTI_HOTEND, if (old_tool_index != 0) tool_change(old_tool_index));
+  probe.use_probing_tool(false);
   return;
 }
 

Marlin/src/gcode/bedlevel/G35.cpp

@@ -86,11 +86,7 @@ void GcodeSuite::G35() {
     workspace_plane = PLANE_XY;
   #endif
 
-  // Always home with tool 0 active
-  #if HAS_MULTI_HOTEND
-    const uint8_t old_tool_index = active_extruder;
-    tool_change(0, true);
-  #endif
+  probe.use_probing_tool();
 
   // Disable duplication mode on homing
   TERN_(HAS_DUPLICATION_MODE, set_duplication_enabled(false));
@@ -153,9 +149,7 @@ void GcodeSuite::G35() {
     SERIAL_ECHOLNPGM("G35 aborted.");
 
   // Restore the active tool after homing
-  #if HAS_MULTI_HOTEND
-    if (old_tool_index != 0) tool_change(old_tool_index, DISABLED(PARKING_EXTRUDER)); // Fetch previous toolhead if not PARKING_EXTRUDER
-  #endif
+  probe.use_probing_tool(false);
 
   #if BOTH(HAS_LEVELING, RESTORE_LEVELING_AFTER_G35)
     set_bed_leveling_enabled(leveling_was_active);

Marlin/src/gcode/bedlevel/abl/G29.cpp

@@ -97,10 +97,6 @@ public:
   bool      dryrun,
             reenable;
 
-  #if HAS_MULTI_HOTEND
-    uint8_t tool_index;
-  #endif
-
   #if EITHER(PROBE_MANUALLY, AUTO_BED_LEVELING_LINEAR)
     int abl_probe_index;
   #endif
@@ -281,10 +277,7 @@ G29_TYPE GcodeSuite::G29() {
    */
   if (!g29_in_progress) {
 
-    #if HAS_MULTI_HOTEND
-      abl.tool_index = active_extruder;
-      if (active_extruder != 0) tool_change(0, true);
-    #endif
+    probe.use_probing_tool();
 
     #if EITHER(PROBE_MANUALLY, AUTO_BED_LEVELING_LINEAR)
       abl.abl_probe_index = -1;
@@ -947,7 +940,7 @@ G29_TYPE GcodeSuite::G29() {
     process_subcommands_now(F(Z_PROBE_END_SCRIPT));
   #endif
 
-  TERN_(HAS_MULTI_HOTEND, if (abl.tool_index != 0) tool_change(abl.tool_index));
+  probe.use_probing_tool(false);
 
   report_current_position();
 

Marlin/src/gcode/bedlevel/mbl/G29.cpp

@@ -103,9 +103,8 @@ void GcodeSuite::G29() {
       bedlevel.reset();
       mbl_probe_index = 0;
       if (!ui.wait_for_move) {
-        queue.inject(parser.seen_test('N') ? F("G28" TERN(CAN_SET_LEVELING_AFTER_G28, "L0", "") "\nG29S2") : F("G29S2"));
-        TERN_(EXTENSIBLE_UI, ExtUI::onLevelingStart());
-        TERN_(DWIN_LCD_PROUI, DWIN_LevelingStart());
+        if (parser.seen_test('N'))
+          queue.inject(F("G28" TERN_(CAN_SET_LEVELING_AFTER_G28, "L0")));
 
         // Position bed horizontally and Z probe vertically.
         #if HAS_SAFE_BED_LEVELING
@@ -141,6 +140,11 @@ void GcodeSuite::G29() {
           do_blocking_move_to(safe_position);
         #endif // HAS_SAFE_BED_LEVELING
 
+        queue.inject(F("G29S2"));
+
+        TERN_(EXTENSIBLE_UI, ExtUI::onLevelingStart());
+        TERN_(DWIN_LCD_PROUI, DWIN_LevelingStart());
+
         return;
       }
       state = MeshNext;

Marlin/src/gcode/calibrate/G33.cpp

@@ -63,10 +63,6 @@ enum CalEnum : char {                        // the 7 main calibration points -
 #define LOOP_CAL_RAD(VAR) LOOP_CAL_PT(VAR, __A, _7P_STEP)
 #define LOOP_CAL_ACT(VAR, _4P, _OP) LOOP_CAL_PT(VAR, _OP ? _AB : __A, _4P ? _4P_STEP : _7P_STEP)
 
-#if HAS_MULTI_HOTEND
-  const uint8_t old_tool_index = active_extruder;
-#endif
-
 float lcd_probe_pt(const xy_pos_t &xy);
 
 void ac_home() {
@@ -78,7 +74,7 @@ void ac_home() {
 }
 
 void ac_setup(const bool reset_bed) {
-  TERN_(HAS_MULTI_HOTEND, tool_change(0, true));
+  TERN_(HAS_BED_PROBE, probe.use_probing_tool());
 
   planner.synchronize();
   remember_feedrate_scaling_off();
@@ -92,7 +88,7 @@ void ac_cleanup(TERN_(HAS_MULTI_HOTEND, const uint8_t old_tool_index)) {
   TERN_(DELTA_HOME_TO_SAFE_ZONE, do_blocking_move_to_z(delta_clip_start_height));
   TERN_(HAS_BED_PROBE, probe.stow());
   restore_feedrate_and_scaling();
-  TERN_(HAS_MULTI_HOTEND, tool_change(old_tool_index, true));
+  TERN_(HAS_BED_PROBE, probe.use_probing_tool(false));
 }
 
 void print_signed_float(FSTR_P const prefix, const_float_t f) {

Marlin/src/gcode/calibrate/G34_M422.cpp

@@ -108,6 +108,7 @@ void GcodeSuite::G34() {
   }
 
   #if ENABLED(Z_STEPPER_AUTO_ALIGN)
+
     do { // break out on error
 
       const int8_t z_auto_align_iterations = parser.intval('I', Z_STEPPER_ALIGN_ITERATIONS);
@@ -142,11 +143,7 @@ void GcodeSuite::G34() {
 
       TERN_(CNC_WORKSPACE_PLANES, workspace_plane = PLANE_XY);
 
-      // Always home with tool 0 active
-      #if HAS_MULTI_HOTEND
-        const uint8_t old_tool_index = active_extruder;
-        tool_change(0, true);
-      #endif
+      probe.use_probing_tool();
 
       TERN_(HAS_DUPLICATION_MODE, set_duplication_enabled(false));
 
@@ -448,14 +445,16 @@ void GcodeSuite::G34() {
         sync_plan_position();
       #endif
 
-      // Restore the active tool after homing
-      TERN_(HAS_MULTI_HOTEND, tool_change(old_tool_index, DISABLED(PARKING_EXTRUDER))); // Fetch previous tool for parking extruder
+      probe.use_probing_tool(false);
 
       #if BOTH(HAS_LEVELING, RESTORE_LEVELING_AFTER_G34)
         set_bed_leveling_enabled(leveling_was_active);
       #endif
 
     }while(0);
+
+    probe.use_probing_tool(false);
+
   #endif // Z_STEPPER_AUTO_ALIGN
 }
 

Marlin/src/gcode/probe/G30.cpp

@@ -53,10 +53,7 @@
  */
 void GcodeSuite::G30() {
 
-  #if HAS_MULTI_HOTEND
-    const uint8_t old_tool_index = active_extruder;
-    tool_change(0);
-  #endif
+  probe.use_probing_tool();
 
   // Convert the given logical position to native position
   const xy_pos_t pos = {
@@ -106,8 +103,7 @@ void GcodeSuite::G30() {
     #endif
   }
 
-  // Restore the active tool
-  TERN_(HAS_MULTI_HOTEND, tool_change(old_tool_index));
+  probe.use_probing_tool(false);
 }
 
 #endif // HAS_BED_PROBE

Marlin/src/inc/Conditionals_LCD.h

@@ -1110,6 +1110,14 @@
   #define HAS_BED_PROBE 1
 #endif
 
+// Probing tool change
+#if !HAS_MULTI_EXTRUDER
+  #undef PROBING_TOOL
+#endif
+#if HAS_BED_PROBE && defined(PROBING_TOOL)
+  #define DO_TOOLCHANGE_FOR_PROBING 1
+#endif
+
 /**
  * Fill in undefined Filament Sensor options
  */

Marlin/src/inc/SanityCheck.h

@@ -2664,6 +2664,10 @@ static_assert(X_MAX_LENGTH >= X_BED_SIZE, "Movement bounds (X_MIN_POS, X_MAX_POS
   #endif // HOTENDS > 2
 #endif // HAS_MULTI_HOTEND
 
+#if DO_TOOLCHANGE_FOR_PROBING && PROBING_TOOL >= EXTRUDERS
+  #error "PROBING_TOOL must be a valid tool index."
+#endif
+
 /**
  * Pins must be set for temp sensors, with some other feature requirements.
  */