From 4ce9ddbb74052bce8799326e03bd9f5daa081957 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Mon, 15 Jun 2015 17:50:26 -0700
Subject: [PATCH 1/4] Check the temperature before filament change

---
 Marlin/Marlin_main.cpp                | 6 ++++++
 Marlin/configurator/config/language.h | 1 +
 Marlin/language.h                     | 1 +
 3 files changed, 8 insertions(+)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 24eb891151..3dae65f713 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4891,6 +4891,12 @@ inline void gcode_M503() {
    */
   inline void gcode_M600() {
     float target[NUM_AXIS], lastpos[NUM_AXIS], fr60 = feedrate / 60;
+    if (degHotend(active_extruder) < extrude_min_temp) {
+      SERIAL_ERROR_START;
+      SERIAL_ERRORLNPGM(MSG_TOO_COLD_FOR_M600);
+      return;
+    }
+
     for (int i=0; i<NUM_AXIS; i++)
       target[i] = lastpos[i] = current_position[i];
 
diff --git a/Marlin/configurator/config/language.h b/Marlin/configurator/config/language.h
index 5f3d790c5e..f83a0d9a1e 100644
--- a/Marlin/configurator/config/language.h
+++ b/Marlin/configurator/config/language.h
@@ -170,6 +170,7 @@
 #define MSG_ENDSTOPS_HIT                    "endstops hit: "
 #define MSG_ERR_COLD_EXTRUDE_STOP           " cold extrusion prevented"
 #define MSG_ERR_LONG_EXTRUDE_STOP           " too long extrusion prevented"
+#define MSG_TOO_COLD_FOR_M600               "M600 Hotend too cold to change filament"
 #define MSG_BABYSTEPPING_X                  "Babystepping X"
 #define MSG_BABYSTEPPING_Y                  "Babystepping Y"
 #define MSG_BABYSTEPPING_Z                  "Babystepping Z"
diff --git a/Marlin/language.h b/Marlin/language.h
index eb20a5b92b..1405252700 100644
--- a/Marlin/language.h
+++ b/Marlin/language.h
@@ -171,6 +171,7 @@
 #define MSG_ENDSTOPS_HIT                    "endstops hit: "
 #define MSG_ERR_COLD_EXTRUDE_STOP           " cold extrusion prevented"
 #define MSG_ERR_LONG_EXTRUDE_STOP           " too long extrusion prevented"
+#define MSG_TOO_COLD_FOR_M600               "M600 Hotend too cold to change filament"
 #define MSG_BABYSTEPPING_X                  "Babystepping X"
 #define MSG_BABYSTEPPING_Y                  "Babystepping Y"
 #define MSG_BABYSTEPPING_Z                  "Babystepping Z"

From 97ec224d72247537ed1c498f1660e4eee4c58709 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Mon, 15 Jun 2015 17:52:51 -0700
Subject: [PATCH 2/4] Replace target with destination in M600

---
 Marlin/Marlin_main.cpp | 53 ++++++++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 3dae65f713..2d9ea465e6 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4890,55 +4890,57 @@ inline void gcode_M503() {
    * M600: Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
    */
   inline void gcode_M600() {
-    float target[NUM_AXIS], lastpos[NUM_AXIS], fr60 = feedrate / 60;
+
     if (degHotend(active_extruder) < extrude_min_temp) {
       SERIAL_ERROR_START;
       SERIAL_ERRORLNPGM(MSG_TOO_COLD_FOR_M600);
       return;
     }
 
+    float lastpos[NUM_AXIS], fr60 = feedrate / 60;
+
     for (int i=0; i<NUM_AXIS; i++)
-      target[i] = lastpos[i] = current_position[i];
+      lastpos[i] = destination[i] = current_position[i];
 
-    #define BASICPLAN plan_buffer_line(target[X_AXIS], target[Y_AXIS], target[Z_AXIS], target[E_AXIS], fr60, active_extruder);
     #ifdef DELTA
-      #define RUNPLAN calculate_delta(target); BASICPLAN
+      #define RUNPLAN calculate_delta(destination); \
+                      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], destination[E_AXIS], fr60, active_extruder);
     #else
-      #define RUNPLAN BASICPLAN
+      #define RUNPLAN line_to_destination();
     #endif
 
     //retract by E
-    if (code_seen('E')) target[E_AXIS] += code_value();
+    if (code_seen('E')) destination[E_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_FIRSTRETRACT
-      else target[E_AXIS] += FILAMENTCHANGE_FIRSTRETRACT;
+      else destination[E_AXIS] += FILAMENTCHANGE_FIRSTRETRACT;
     #endif
 
     RUNPLAN;
 
     //lift Z
-    if (code_seen('Z')) target[Z_AXIS] += code_value();
+    if (code_seen('Z')) destination[Z_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_ZADD
-      else target[Z_AXIS] += FILAMENTCHANGE_ZADD;
+      else destination[Z_AXIS] += FILAMENTCHANGE_ZADD;
     #endif
 
     RUNPLAN;
 
     //move xy
-    if (code_seen('X')) target[X_AXIS] = code_value();
+    if (code_seen('X')) destination[X_AXIS] = code_value();
     #ifdef FILAMENTCHANGE_XPOS
-      else target[X_AXIS] = FILAMENTCHANGE_XPOS;
+      else destination[X_AXIS] = FILAMENTCHANGE_XPOS;
     #endif
 
-    if (code_seen('Y')) target[Y_AXIS] = code_value();
+    if (code_seen('Y')) destination[Y_AXIS] = code_value();
     #ifdef FILAMENTCHANGE_YPOS
-      else target[Y_AXIS] = FILAMENTCHANGE_YPOS;
+      else destination[Y_AXIS] = FILAMENTCHANGE_YPOS;
     #endif
 
     RUNPLAN;
 
-    if (code_seen('L')) target[E_AXIS] += code_value();
+    if (code_seen('L')) destination[E_AXIS] += code_value();
     #ifdef FILAMENTCHANGE_FINALRETRACT
-      else target[E_AXIS] += FILAMENTCHANGE_FINALRETRACT;
+      else destination[E_AXIS] += FILAMENTCHANGE_FINALRETRACT;
     #endif
 
     RUNPLAN;
@@ -4972,12 +4974,12 @@ inline void gcode_M503() {
     #endif
           
     //return to normal
-    if (code_seen('L')) target[E_AXIS] -= code_value();
+    if (code_seen('L')) destination[E_AXIS] -= code_value();
     #ifdef FILAMENTCHANGE_FINALRETRACT
-      else target[E_AXIS] -= FILAMENTCHANGE_FINALRETRACT;
+      else destination[E_AXIS] -= FILAMENTCHANGE_FINALRETRACT;
     #endif
 
-    current_position[E_AXIS] = target[E_AXIS]; //the long retract of L is compensated by manual filament feeding
+    current_position[E_AXIS] = destination[E_AXIS]; //the long retract of L is compensated by manual filament feeding
     plan_set_e_position(current_position[E_AXIS]);
 
     RUNPLAN; //should do nothing
@@ -4986,12 +4988,17 @@ inline void gcode_M503() {
 
     #ifdef DELTA
       calculate_delta(lastpos);
-      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move xyz back
-      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder); //final untretract
+      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], destination[E_AXIS], fr60, active_extruder);
+      plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder);
     #else
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], target[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move xy back
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], lastpos[Z_AXIS], target[E_AXIS], fr60, active_extruder); //move z back
-      plan_buffer_line(lastpos[X_AXIS], lastpos[Y_AXIS], lastpos[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder); //final untretract
+      // Move XY to starting position, then Z, then E
+      destination[X_AXIS] = lastpos[X_AXIS];
+      destination[Y_AXIS] = lastpos[Y_AXIS];
+      line_to_destination();
+      destination[Z_AXIS] = lastpos[Z_AXIS];
+      line_to_destination();
+      destination[E_AXIS] = lastpos[E_AXIS];
+      line_to_destination();
     #endif        
 
     #ifdef FILAMENT_RUNOUT_SENSOR

From fb16a83b8ab491efb8c1f4c0c901d0a186e96d5f Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Mon, 15 Jun 2015 17:54:41 -0700
Subject: [PATCH 3/4] Cleanup M600 documentation comments

---
 Marlin/Marlin_main.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 2d9ea465e6..4b77c64bae 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4887,7 +4887,16 @@ inline void gcode_M503() {
 #ifdef FILAMENTCHANGEENABLE
 
   /**
-   * M600: Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
+   * M600: Pause for filament change
+   *
+   *  E[distance] - Retract the filament this far (negative value)
+   *  Z[distance] - Move the Z axis by this distance
+   *  X[position] - Move to this X position, with Y
+   *  Y[position] - Move to this Y position, with X
+   *  L[distance] - Retract distance for removal (manual reload)
+   *
+   *  Default values are used for omitted arguments.
+   *
    */
   inline void gcode_M600() {
 
@@ -4987,6 +4996,7 @@ inline void gcode_M503() {
     lcd_reset_alert_level();
 
     #ifdef DELTA
+      // Move XYZ to starting position, then E
       calculate_delta(lastpos);
       plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], destination[E_AXIS], fr60, active_extruder);
       plan_buffer_line(delta[X_AXIS], delta[Y_AXIS], delta[Z_AXIS], lastpos[E_AXIS], fr60, active_extruder);

From 5ccb1c9e7d49dc2496574b925d74f78393606028 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Mon, 15 Jun 2015 17:55:39 -0700
Subject: [PATCH 4/4] Use millis for M600 audio feedback interval

---
 Marlin/Marlin_main.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 4b77c64bae..9a7c290942 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -4963,10 +4963,14 @@ inline void gcode_M503() {
     disable_e3();
     delay(100);
     LCD_ALERTMESSAGEPGM(MSG_FILAMENTCHANGE);
-    uint8_t cnt = 0;
+    millis_t next_tick = 0;
     while (!lcd_clicked()) {
       #ifndef AUTO_FILAMENT_CHANGE
-        if (++cnt == 0) lcd_quick_feedback(); // every 256th frame till the lcd is clicked
+        millis_t ms = millis();
+        if (ms >= next_tick) {
+          lcd_quick_feedback();
+          next_tick = ms + 2500; // feedback every 2.5s while waiting
+        }
         manage_heater();
         manage_inactivity(true);
         lcd_update();
@@ -4976,6 +4980,7 @@ inline void gcode_M503() {
         st_synchronize();
       #endif
     } // while(!lcd_clicked)
+    lcd_quick_feedback(); // click sound feedback
 
     #ifdef AUTO_FILAMENT_CHANGE
       current_position[E_AXIS]= 0;