Message for every KILL and STOP

No more mystery halts & resets

Moved messages to language.h

Added current command to inactive timeout message

Marlin/Marlin_main.cpp

@@ -2030,14 +2030,26 @@ static void clean_up_after_endstop_or_probe_move() {
         set_bltouch_deployed(true);        // Also needs to deploy and stow to
         set_bltouch_deployed(false);       // clear the triggered condition.
         if (TEST_BLTOUCH()) {              // If it still claims to be triggered...
+          SERIAL_ERROR_START;
+          SERIAL_ERRORLNPGM(MSG_STOP_BLTOUCH);
           stop();                          // punt!
           return true;
         }
       }
     #elif ENABLED(Z_PROBE_SLED)
-      if (axis_unhomed_error(true, false, false)) { stop(); return true; }
+      if (axis_unhomed_error(true, false, false)) {
+        SERIAL_ERROR_START;
+        SERIAL_ERRORLNPGM(MSG_STOP_UNHOMED);
+        stop();
+        return true;
+      }
     #elif ENABLED(Z_PROBE_ALLEN_KEY)
-      if (axis_unhomed_error(true, true,  true )) { stop(); return true; }
+      if (axis_unhomed_error(true, true,  true )) {
+        SERIAL_ERROR_START;
+        SERIAL_ERRORLNPGM(MSG_STOP_UNHOMED);
+        stop();
+        return true;
+      }
     #endif
 
     const float oldXpos = current_position[X_AXIS],
@@ -10298,7 +10310,11 @@ void manage_inactivity(bool ignore_stepper_queue/*=false*/) {
 
   millis_t ms = millis();
 
-  if (max_inactive_time && ELAPSED(ms, previous_cmd_ms + max_inactive_time)) kill(PSTR(MSG_KILLED));
+  if (max_inactive_time && ELAPSED(ms, previous_cmd_ms + max_inactive_time)) {
+    SERIAL_ERROR_START;
+    SERIAL_ECHOLNPAIR(MSG_KILL_INACTIVE_TIME, current_command);
+    kill(PSTR(MSG_KILLED));
+  }
 
   // Prevent steppers timing-out in the middle of M600
   #if ENABLED(FILAMENT_CHANGE_FEATURE) && ENABLED(FILAMENT_CHANGE_NO_STEPPER_TIMEOUT)
@@ -10348,7 +10364,11 @@ void manage_inactivity(bool ignore_stepper_queue/*=false*/) {
     // Exceeded threshold and we can confirm that it was not accidental
     // KILL the machine
     // ----------------------------------------------------------------
-    if (killCount >= KILL_DELAY) kill(PSTR(MSG_KILLED));
+    if (killCount >= KILL_DELAY) {
+      SERIAL_ERROR_START;
+      SERIAL_ERRORLNPGM(MSG_KILL_BUTTON);
+      kill(PSTR(MSG_KILLED));
+    }
   #endif
 
   #if HAS_HOME

Marlin/language.h

@@ -200,6 +200,11 @@
 
 #define MSG_ERR_EEPROM_WRITE                "Error writing to EEPROM!"
 
+#define MSG_STOP_BLTOUCH                    "STOP called because of BLTouch error - restart with M999"
+#define MSG_STOP_UNHOMED                    "STOP called because of unhomed error - restart with M999"
+#define MSG_KILL_INACTIVE_TIME              "KILL caused by too much inactive time - current command: "
+#define MSG_KILL_BUTTON                     "KILL caused by KILL button/pin"
+
 // temperature.cpp strings
 #define MSG_PID_AUTOTUNE                    "PID Autotune"
 #define MSG_PID_AUTOTUNE_START              MSG_PID_AUTOTUNE " start"