✨ Optional HOST_STATUS_NOTIFICATIONS (#22833)

Marlin/Configuration_adv.h

  */
 //#define HOST_ACTION_COMMANDS
 #if ENABLED(HOST_ACTION_COMMANDS)
-  //#define HOST_PAUSE_M76
-  //#define HOST_PROMPT_SUPPORT
-  //#define HOST_START_MENU_ITEM      // Add a menu item that tells the host to start
-  //#define HOST_SHUTDOWN_MENU_ITEM   // Add a menu item that tells the host to shut down
+  //#define HOST_PAUSE_M76                // Tell the host to pause in response to M76
+  //#define HOST_PROMPT_SUPPORT           // Initiate host prompts to get user feedback
+  #if ENABLED(HOST_PROMPT_SUPPORT)
+    //#define HOST_STATUS_NOTIFICATIONS   // Send some status messages to the host as notifications
+  #endif
+  //#define HOST_START_MENU_ITEM          // Add a menu item that tells the host to start
+  //#define HOST_SHUTDOWN_MENU_ITEM       // Add a menu item that tells the host to shut down
 #endif
 
 /**

Marlin/src/gcode/control/M111.cpp

 
 #include "../gcode.h"
 
+#if ENABLED(HOST_ACTION_COMMANDS)
+  #include "../../feature/host_actions.h"
+#endif
+
 /**
  * M111: Set the debug level
  */
 void GcodeSuite::M111() {
   if (parser.seenval('S')) marlin_debug_flags = parser.value_byte();
 
+  #if EITHER(HOST_ACTION_COMMANDS, HOST_PROMPT_SUPPORT)
+    if (parser.seenval('H')) hostui.flag.bits = parser.value_byte();
+  #endif
+
   static PGMSTR(str_debug_1, STR_DEBUG_ECHO);
   static PGMSTR(str_debug_2, STR_DEBUG_INFO);
   static PGMSTR(str_debug_4, STR_DEBUG_ERRORS);

Marlin/src/inc/SanityCheck.h

   #error "DEFAULT_LCD_BRIGHTNESS is now LCD_BRIGHTNESS_DEFAULT."
 #endif
 
-#if MB(DUE3DOM_MINI) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
-  #warning "Onboard temperature sensor for BOARD_DUE3DOM_MINI has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
-#elif MB(BTT_SKR_E3_TURBO) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
-  #warning "Onboard temperature sensor for BOARD_BTT_SKR_E3_TURBO has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
-#endif
-
 constexpr float arm[] = AXIS_RELATIVE_MODES;
 static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _LOGICAL_AXES_STR "elements.");
 

Marlin/src/inc/Warnings.cpp

   #warning "Your Configuration provides no method to acquire user feedback!"
 #endif
 
+#if MB(DUE3DOM_MINI) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
+  #warning "Onboard temperature sensor for BOARD_DUE3DOM_MINI has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
+#elif MB(BTT_SKR_E3_TURBO) && PIN_EXISTS(TEMP_2) && DISABLED(TEMP_SENSOR_BOARD)
+  #warning "Onboard temperature sensor for BOARD_BTT_SKR_E3_TURBO has moved from TEMP_SENSOR_2 (TEMP_2_PIN) to TEMP_SENSOR_BOARD (TEMP_BOARD_PIN)."
+#endif
+
 #ifndef NO_AUTO_ASSIGN_WARNING
 
   #if AUTO_ASSIGNED_X2_STEPPER
   #warning "Creality 4.2.2 boards come with a variety of stepper drivers. Check the board label and set the correct *_DRIVER_TYPE! (C=HR4988, E=A4988, A=TMC2208, B=TMC2209, H=TMC2225)."
 #endif
 
+#if PRINTCOUNTER_SYNC
+  #warning "To prevent step loss, motion will pause for PRINTCOUNTER auto-save."
+#endif
+
 #if HOMING_Z_WITH_PROBE && IS_CARTESIAN && DISABLED(Z_SAFE_HOMING)
   #error "Z_SAFE_HOMING is recommended when homing with a probe. Enable Z_SAFE_HOMING or comment out this line to continue."
 #endif

Marlin/src/lcd/marlinui.cpp

   void MarlinUI::set_status(const char * const cstr, const bool persist) {
     if (alert_level) return;
 
-    TERN_(HOST_PROMPT_SUPPORT, hostui.notify(cstr));
+    TERN_(HOST_STATUS_NOTIFICATIONS, hostui.notify(cstr));
 
     // Here we have a problem. The message is encoded in UTF8, so
     // arbitrarily cutting it will be a problem. We MUST be sure
     if (level < alert_level) return;
     alert_level = level;
 
-    TERN_(HOST_PROMPT_SUPPORT, hostui.notify(fstr));
+    TERN_(HOST_STATUS_NOTIFICATIONS, hostui.notify(fstr));
 
     // Since the message is encoded in UTF8 it must
     // only be cut on a character boundary.
     va_start(args, FTOP(fmt));
     vsnprintf_P(status_message, MAX_MESSAGE_LENGTH, FTOP(fmt), args);
     va_end(args);
+
+    TERN_(HOST_STATUS_NOTIFICATIONS, hostui.notify(status_message));
+
     finish_status(level > 0);
   }
 

Marlin/src/module/printcounter.cpp

 
 #if PRINTCOUNTER_SYNC
   #include "../module/planner.h"
-  #warning "To prevent step loss, motion will pause for PRINTCOUNTER auto-save."
 #endif
 
 // Service intervals

Marlin/src/module/settings.cpp

   #include "../lcd/e3v2/jyersui/dwin.h"
 #endif
 
+#if ENABLED(HOST_PROMPT_SUPPORT)
+  #include "../feature/host_actions.h"
+#endif
+
 #if HAS_SERVOS
   #include "servo.h"
 #endif
 #define DEBUG_OUT EITHER(EEPROM_CHITCHAT, DEBUG_LEVELING_FEATURE)
 #include "../core/debug_out.h"
 
+#if BOTH(EEPROM_CHITCHAT, HOST_PROMPT_SUPPORT)
+  #define HOST_EEPROM_CHITCHAT 1
+#endif
+
 #if ENABLED(EEPROM_SETTINGS)
 
   #define EEPROM_ASSERT(TST,ERR)  do{ if (!(TST)) { SERIAL_ERROR_MSG(ERR); eeprom_error = true; } }while(0)
         store_mesh(ubl.storage_slot);
     #endif
 
-    if (!eeprom_error) LCD_MESSAGE(MSG_SETTINGS_STORED);
+    if (!eeprom_error) {
+      LCD_MESSAGE(MSG_SETTINGS_STORED);
+      TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_SETTINGS_STORED)));
+    }
 
     TERN_(EXTENSIBLE_UI, ExtUI::onConfigurationStoreWritten(!eeprom_error));
 
       }
       DEBUG_ECHO_MSG("EEPROM version mismatch (EEPROM=", stored_ver, " Marlin=" EEPROM_VERSION ")");
       TERN_(DWIN_CREALITY_LCD_ENHANCED, LCD_MESSAGE(MSG_ERR_EEPROM_VERSION));
+      TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_ERR_EEPROM_VERSION)));
 
       IF_DISABLED(EEPROM_AUTO_INIT, ui.eeprom_alert_version());
       eeprom_error = true;
         eeprom_error = true;
         DEBUG_ERROR_MSG("EEPROM CRC mismatch - (stored) ", stored_crc, " != ", working_crc, " (calculated)!");
         TERN_(DWIN_CREALITY_LCD_ENHANCED, LCD_MESSAGE(MSG_ERR_EEPROM_CRC));
+        TERN_(HOST_EEPROM_CHITCHAT, hostui.notify(GET_TEXT_F(MSG_ERR_EEPROM_CRC)));
         IF_DISABLED(EEPROM_AUTO_INIT, ui.eeprom_alert_crc());
       }
       else if (!validating) {
         DEBUG_ECHO_START();
         DEBUG_ECHO(version);
         DEBUG_ECHOLNPGM(" stored settings retrieved (", eeprom_index - (EEPROM_OFFSET), " bytes; crc ", (uint32_t)working_crc, ")");
+        TERN_(HOST_EEPROM_CHITCHAT, hostui.notify(F("Stored settings retrieved")));
       }
 
       if (!validating && !eeprom_error) postprocess();
     #endif
   #endif
 
-  TERN_(EXTENSIBLE_UI, ExtUI::onFactoryReset());
   TERN_(DWIN_CREALITY_LCD_ENHANCED, DWIN_SetDataDefaults());
   TERN_(DWIN_CREALITY_LCD_JYERSUI, CrealityDWIN.Reset_Settings());
 
 
   postprocess();
 
-  DEBUG_ECHO_MSG("Hardcoded Default Settings Loaded");
+  FSTR_P const hdsl = F("Hardcoded Default Settings Loaded");
+  TERN_(HOST_EEPROM_CHITCHAT, hostui.notify(hdsl));
+  DEBUG_ECHO_START(); DEBUG_ECHOLNF(hdsl);
+
+  TERN_(EXTENSIBLE_UI, ExtUI::onFactoryReset());
 }
 
 #if DISABLED(DISABLE_M503)

Marlin/src/module/temperature.cpp

       SERIAL_ECHOLNPGM(STR_PID_TEMP_TOO_HIGH);
       TERN_(EXTENSIBLE_UI, ExtUI::onPidTuning(ExtUI::result_t::PID_TEMP_TOO_HIGH));
       TERN_(DWIN_CREALITY_LCD_ENHANCED, DWIN_PidTuning(PID_TEMP_TOO_HIGH));
+      TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_PID_TEMP_TOO_HIGH)));
       return;
     }
 
         SERIAL_ECHOLNPGM(STR_PID_TEMP_TOO_HIGH);
         TERN_(EXTENSIBLE_UI, ExtUI::onPidTuning(ExtUI::result_t::PID_TEMP_TOO_HIGH));
         TERN_(DWIN_CREALITY_LCD_ENHANCED, DWIN_PidTuning(PID_TEMP_TOO_HIGH));
+        TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_PID_TEMP_TOO_HIGH)));
         break;
       }
 
         TERN_(DWIN_CREALITY_LCD, DWIN_Popup_Temperature(0));
         TERN_(DWIN_CREALITY_LCD_ENHANCED, DWIN_PidTuning(PID_TUNING_TIMEOUT));
         TERN_(EXTENSIBLE_UI, ExtUI::onPidTuning(ExtUI::result_t::PID_TUNING_TIMEOUT));
+        TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_PID_TIMEOUT)));
         SERIAL_ECHOLNPGM(STR_PID_TIMEOUT);
         break;
       }
 
       if (cycles > ncycles && cycles > 2) {
         SERIAL_ECHOLNPGM(STR_PID_AUTOTUNE_FINISHED);
+        TERN_(HOST_PROMPT_SUPPORT, hostui.notify(GET_TEXT_F(MSG_PID_AUTOTUNE_DONE)));
 
         #if EITHER(PIDTEMPBED, PIDTEMPCHAMBER)
           FSTR_P const estring = GHV(F("chamber"), F("bed"), FPSTR(NUL_STR));

buildroot/tests/rambo

         FAN_MIN_PWM 50 FAN_KICKSTART_TIME 100 \
         XY_FREQUENCY_LIMIT 15
 opt_enable COREYX USE_XMAX_PLUG MIXING_EXTRUDER GRADIENT_MIX \
-           BABYSTEPPING BABYSTEP_DISPLAY_TOTAL FILAMENT_LCD_DISPLAY FILAMENT_WIDTH_SENSOR \
+           BABYSTEPPING BABYSTEP_DISPLAY_TOTAL FILAMENT_LCD_DISPLAY \
            REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER MENU_ADDAUTOSTART SDSUPPORT SDCARD_SORT_ALPHA \
            ENDSTOP_NOISE_THRESHOLD FAN_SOFT_PWM \
            FIX_MOUNTED_PROBE PROBING_ESTEPPERS_OFF PROBE_OFFSET_WIZARD \