Split first layer calibration load filament and intro line into separate steps. If load fails, pause print apparently flushes command buffer and intro line is not printed after issue is resolved.

Firmware/first_lay_cal.cpp

@@ -40,15 +40,26 @@ void lay1cal_preheat()
 
 }
 
-//! @brief Print intro line
+//! @brief Load filament
 //! @param cmd_buffer character buffer needed to format gcodes
 //! @param filament filament to use (applies for MMU only)
-void lay1cal_intro_line(char *cmd_buffer, uint8_t filament)
+void lay1cal_load_filament(char *cmd_buffer, uint8_t filament)
+{
+    if (mmu_enabled)
+    {
+        enquecommand_P(PSTR("M83"));
+        enquecommand_P(PSTR("G1 Y-3.0 F1000.0"));
+        enquecommand_P(PSTR("G1 Z0.4 F1000.0"));
+        sprintf_P(cmd_buffer, PSTR("T%d"), filament);
+        enquecommand(cmd_buffer);
+    }
+
+}
+
+//! @brief Print intro line
+void lay1cal_intro_line()
 {
-    static const char cmd_intro_mmu_0[] PROGMEM = "M83";
-    static const char cmd_intro_mmu_1[] PROGMEM = "G1 Y-3.0 F1000.0";
-    static const char cmd_intro_mmu_2[] PROGMEM = "G1 Z0.4 F1000.0";
-    static const char cmd_intro_mmu_3[] PROGMEM = "G1 X55.0 E32.0 F1073.0"; // call T code before
+    static const char cmd_intro_mmu_3[] PROGMEM = "G1 X55.0 E32.0 F1073.0";
     static const char cmd_intro_mmu_4[] PROGMEM = "G1 X5.0 E32.0 F1800.0";
     static const char cmd_intro_mmu_5[] PROGMEM = "G1 X55.0 E8.0 F2000.0";
     static const char cmd_intro_mmu_6[] PROGMEM = "G1 Z0.3 F1000.0";
@@ -61,10 +72,7 @@ void lay1cal_intro_line(char *cmd_buffer, uint8_t filament)
 
     static const char * const intro_mmu_cmd[] PROGMEM =
     {
-        cmd_intro_mmu_0,
-        cmd_intro_mmu_1,
-        cmd_intro_mmu_2,
-        cmd_intro_mmu_3, // call T code before
+        cmd_intro_mmu_3,
         cmd_intro_mmu_4,
         cmd_intro_mmu_5,
         cmd_intro_mmu_6,
@@ -80,11 +88,6 @@ void lay1cal_intro_line(char *cmd_buffer, uint8_t filament)
     {
         for (uint8_t i = 0; i < (sizeof(intro_mmu_cmd)/sizeof(intro_mmu_cmd[0])); ++i)
         {
-            if (3 == i)
-                {
-                    sprintf_P(cmd_buffer, PSTR("T%d"), filament);
-                    enquecommand(cmd_buffer);
-                }
             enquecommand_P(static_cast<char*>(pgm_read_ptr(&intro_mmu_cmd[i])));
         }
     }

Firmware/first_lay_cal.h

@@ -7,7 +7,8 @@
 #include <stdint.h>
 
 void lay1cal_preheat();
-void lay1cal_intro_line(char *cmd_buffer, uint8_t filament);
+void lay1cal_load_filament(char *cmd_buffer, uint8_t filament);
+void lay1cal_intro_line();
 void lay1cal_before_meander();
 void lay1cal_meander(char *cmd_buffer);
 void lay1cal_square(char *cmd_buffer, uint8_t i);

Firmware/ultralcd.cpp

@@ -1359,37 +1359,41 @@ void lcd_commands()
             switch(lcd_commands_step)
             {
             case 0:
-                lcd_commands_step = 10;
+                lcd_commands_step = 11;
                 break;
             case 20:
                 filament = 0;
-                lcd_commands_step = 10;
+                lcd_commands_step = 11;
                 break;
             case 21:
                 filament = 1;
-                lcd_commands_step = 10;
+                lcd_commands_step = 11;
                 break;
             case 22:
                 filament = 2;
-                lcd_commands_step = 10;
+                lcd_commands_step = 11;
                 break;
             case 23:
                 filament = 3;
-                lcd_commands_step = 10;
+                lcd_commands_step = 11;
                 break;
             case 24:
                 filament = 4;
+                lcd_commands_step = 11;
+                break;
+            case 11:
+                lay1cal_preheat();
                 lcd_commands_step = 10;
                 break;
             case 10:
-                lay1cal_preheat();
+                lay1cal_load_filament(cmd1, filament);
                 lcd_commands_step = 9;
                 break;
             case 9:
                 lcd_clear();
                 menu_depth = 0;
                 menu_submenu(lcd_babystep_z);
-                lay1cal_intro_line(cmd1, filament);
+                lay1cal_intro_line();
                 lcd_commands_step = 8;
                 break;
             case 8: