Add safety temperature for nozzle as probe

Marlin/Configuration.h

@@ -884,6 +884,13 @@
  * nozzle system or a piezo-electric smart effector.
  */
 //#define NOZZLE_AS_PROBE
+#if ENABLED(NOZZLE_AS_PROBE)
+  #define PROBE_REQUIRES_MINTEMP // Require a minimum temperature when using the nozzle as a probe
+  #if ENABLED(PROBE_REQUIRES_MINTEMP)
+    #define PROBE_REQUIRES_MINTEMP_NOZZLE 150
+    #define PROBE_REQUIRES_MINTEMP_BED 50
+  #endif
+#endif
 
 /**
  * Z Servo Probe, such as an endstop switch on a rotating arm.

Marlin/src/module/probe.cpp

@@ -348,6 +348,34 @@ bool Probe::set_deployed(const bool deploy) {
     constexpr bool deploy_stow_condition = true;
   #endif
 
+  #if BOTH(NOZZLE_AS_PROBE, PROBE_REQUIRES_MINTEMP)
+    bool setting_hotend, setting_bed = false;
+    #if defined(PROBE_REQUIRES_MINTEMP_NOZZLE) && PROBE_REQUIRES_MINTEMP_NOZZLE < 0 && HAS_TEMP_HOTEND
+      if (thermalManager.degTargetHotend(0) < PROBE_REQUIRES_MINTEMP_NOZZLE) {
+        uint16_t hotendTemperature = AUTOLEVEL_PREHEAT_NOZZLE_TEMP;
+        SERIAL_ECHOLNPAIR("Preheating hot-end to ", hotendTemperature);
+        thermalManager.setTargetHotend(hotendTemperature, 0);
+        setting_hotend = true;
+      }
+    #endif
+
+    #if defined(PROBE_REQUIRES_MINTEMP_BED) && PROBE_REQUIRES_MINTEMP_BED < 0 && HAS_HEATED_BED
+      if (thermalManager.degBed() < PROBE_REQUIRES_MINTEMP_BED) {
+        uint16_t bedTemperature = AUTOLEVEL_PREHEAT_BED_TEMP;
+        SERIAL_ECHOLNPAIR("Preheating bed to ", bedTemperature);
+        thermalManager.setTargetBed(bedTemperature);
+        setting_bed = true;
+      }
+      #endif
+
+    #if HAS_TEMP_HOTEND
+      if (setting_hotend) thermalManager.wait_for_hotend(0);
+    #endif
+    #if HAS_HEATED_BED
+      if (setting_bed) thermalManager.wait_for_bed_heating();
+    #endif
+  #endif
+
   // For beds that fall when Z is powered off only raise for trusted Z
   #if ENABLED(UNKNOWN_Z_NO_RAISE)
     const bool unknown_condition = axis_is_trusted(Z_AXIS);