Fixes for LCD change filament (T1438, T1221)

- "Change filament" now allows extruder selection on dual extruder heads (T1438)
- Fix for broken M600 resume_print; head motion during M600; backport from upstream (T1221)

Marlin/Conditionals_LulzBot.h

@@ -13,7 +13,7 @@
  * got disabled.
  */
 
-#define LULZBOT_FW_VERSION ".55" // Change this with each update
+#define LULZBOT_FW_VERSION ".56" // Change this with each update
 
 #if ( \
     !defined(LULZBOT_Gladiola_Mini) && \
@@ -130,7 +130,7 @@
     #define LULZBOT_SENSORLESS_HOMING
     #define LULZBOT_USE_TMC_STEALTHCHOP_Z
     #define LULZBOT_USE_Z_BELT
-    #define LULZBOT_USE_STATUS_LED
+    #define LULZBOT_USE_EXPERIMENTAL_FEATURES
     #define LULZBOT_BAUDRATE 250000
     #define LULZBOT_PRINTCOUNTER
     #define LULZBOT_UUID "e5502411-d46d-421d-ba3a-a20126d7930f"
@@ -149,7 +149,7 @@
     #define LULZBOT_SENSORLESS_HOMING
     #define LULZBOT_USE_TMC_STEALTHCHOP_Z
     #define LULZBOT_USE_Z_BELT
-    #define LULZBOT_USE_STATUS_LED
+    #define LULZBOT_USE_EXPERIMENTAL_FEATURES
     #define LULZBOT_BAUDRATE 250000
     #define LULZBOT_PRINTCOUNTER
     #define LULZBOT_UUID "e5502411-d46d-421d-ba3a-a20126d7930f"
@@ -249,6 +249,15 @@
 // as described in T1393
 #define LULZBOT_ENDSTOPS_ALWAYS_ON_DEFAULT_WORKAROUND
 
+// Backport of upstream Marlin fix T7811 related to M600 resume_print
+#define LULZBOT_M600_BACKPORT_T7811
+
+/************************* EXPERIMENTAL FEATURES ******************************/
+
+#if defined(LULZBOT_USE_EXPERIMENTAL_FEATURES)
+    #define LULZBOT_USE_STATUS_LED
+#endif
+
 /******************** MOTHERBOARD AND PIN CONFIGURATION ***********************/
 
 #if defined(TOOLHEAD_Devel_ServoDual)
@@ -1798,8 +1807,10 @@
     #define LULZBOT_SCROLL_LONG_FILE_NAMES
     #define LULZBOT_REORDERED_MENUS
     #define LULZBOT_ESTEP_REDUCED_LCD_PRECISION
+    #if LULZBOT_EXTRUDERS > 0
+      #define LULZBOT_CHANGE_FILAMENT_DUAL_EXTRUDER_SUPPORT
+    #endif
 #endif
-
 
 /* Marlin requires static PSTRs to display on the LCD display, because of this */
 /* we have to use a preprocessor trick to append the heater name on temp errors */

Marlin/Marlin_main.cpp

@@ -6343,6 +6343,10 @@ inline void gcode_M17() {
     KEEPALIVE_STATE(IN_HANDLER);
   }
 
+  #if defined(LULZBOT_CHANGE_FILAMENT_DUAL_EXTRUDER_SUPPORT)
+    void LULZBOT_RESTORE_ACTIVE_TOOLHEAD();
+  #endif
+
   static void resume_print(const float &load_length = 0, const float &initial_extrude_length = 0, const int8_t max_beep_count = 0) {
     bool nozzle_timed_out = false;
 
@@ -6360,6 +6364,10 @@ inline void gcode_M17() {
       filament_change_beep(max_beep_count, true);
     #endif
 
+    #if defined(LULZBOT_M600_BACKPORT_T7811)
+    set_destination_to_current();
+    #endif
+
     if (load_length != 0) {
       #if ENABLED(ULTIPANEL)
         // Show "insert filament"
@@ -6439,6 +6447,10 @@ inline void gcode_M17() {
       lcd_advanced_pause_show_message(ADVANCED_PAUSE_MESSAGE_STATUS);
     #endif
 
+    #if defined(LULZBOT_CHANGE_FILAMENT_DUAL_EXTRUDER_SUPPORT)
+    LULZBOT_RESTORE_ACTIVE_TOOLHEAD();
+    #endif
+
     #if ENABLED(SDSUPPORT)
       if (sd_print_paused) {
         card.startFileprint();
@@ -6447,6 +6459,7 @@ inline void gcode_M17() {
     #endif
 
     move_away_flag = false;
+
   }
 #endif // ADVANCED_PAUSE_FEATURE
 

Marlin/ultralcd.cpp

@@ -899,6 +899,33 @@ void kill_screen(const char* lcd_msg) {
   static void lcd_store_settings();
   static void lcd_load_settings();
 
+  #if defined(LULZBOT_CHANGE_FILAMENT_DUAL_EXTRUDER_SUPPORT)
+
+  void tool_change(const uint8_t tmp_extruder, const float fr_mm_s/*=0.0*/, bool no_move/*=false*/);
+
+  static uint8_t active_extruder_before_filament_change = -1;
+
+  void lcd_enqueue_filament_change_e0() {
+    if (axis_unhomed_error()) {lcd_return_to_status(); return;};
+    active_extruder_before_filament_change = active_extruder;
+    tool_change(0, 0, true);
+    lcd_enqueue_filament_change();
+  }
+
+  void lcd_enqueue_filament_change_e1() {
+    if (axis_unhomed_error()) {lcd_return_to_status(); return;};
+    active_extruder_before_filament_change = active_extruder;
+    tool_change(1, 0, true);
+    lcd_enqueue_filament_change();
+  }
+
+  void LULZBOT_RESTORE_ACTIVE_TOOLHEAD() {
+    if(active_extruder_before_filament_change > -1) {
+      tool_change(active_extruder_before_filament_change, 0, true);
+      active_extruder_before_filament_change = -1;
+    }
+  }
+  #endif
 
   void lcd_main_menu() {
     START_MENU();
@@ -908,16 +935,24 @@ void kill_screen(const char* lcd_msg) {
 
     if (isPrinting) {
       MENU_ITEM(submenu, MSG_TUNE, lcd_tune_menu);
-      #if ENABLED(ADVANCED_PAUSE_FEATURE)
-        if (!thermalManager.tooColdToExtrude(active_extruder))
-          MENU_ITEM(function, MSG_FILAMENTCHANGE, lcd_enqueue_filament_change);
-      #endif
     } else {
       MENU_ITEM(submenu, _UxGT("Movement"), lcd_movement_menu);
       MENU_ITEM(submenu, MSG_TEMPERATURE, lcd_control_temperature_menu);
       MENU_ITEM(submenu, _UxGT("Configuration"), lcd_configuration_menu);
     }
 
+    #if ENABLED(ADVANCED_PAUSE_FEATURE)
+      #if defined(LULZBOT_CHANGE_FILAMENT_DUAL_EXTRUDER_SUPPORT)
+        if (!thermalManager.tooColdToExtrude(0))
+          MENU_ITEM(function, MSG_FILAMENTCHANGE " E1", lcd_enqueue_filament_change_e0);
+        if (!thermalManager.tooColdToExtrude(1))
+          MENU_ITEM(function, MSG_FILAMENTCHANGE " E2", lcd_enqueue_filament_change_e1);
+      #else
+        if (!thermalManager.tooColdToExtrude(active_extruder))
+          MENU_ITEM(function, MSG_FILAMENTCHANGE, lcd_enqueue_filament_change_e0);
+      #endif
+    #endif
+
     #if ENABLED(SDSUPPORT)
       if (card.cardOK) {
         if (card.isFileOpen()) {