Merge pull request #2368 from wavexx/unretract_after_lcd_pause

Unretract when resuming a paused print

Firmware/Marlin.h

@@ -308,6 +308,7 @@ extern float max_pos[3];
 extern bool axis_known_position[3];
 extern int fanSpeed;
 extern int8_t lcd_change_fil_state;
+extern float default_retraction;
 
 #ifdef TMC2130
 void homeaxis(int axis, uint8_t cnt = 1, uint8_t* pstep = 0);

Firmware/Marlin_main.cpp

@@ -9568,10 +9568,6 @@ void long_pause() //long pause print
     // Stop heaters
     setAllTargetHotends(0);
 
-	//retract
-	current_position[E_AXIS] -= default_retraction;
-	plan_buffer_line_curposXYZE(400, active_extruder);
-
 	//lift z
 	current_position[Z_AXIS] += Z_PAUSE_LIFT;
 	if (current_position[Z_AXIS] > Z_MAX_POS) current_position[Z_AXIS] = Z_MAX_POS;
@@ -10246,23 +10242,29 @@ void stop_and_save_print_to_ram(float z_move, float e_move)
     // move away from the print.
     char buf[48];
 
-	// First unretract (relative extrusion)
-	if(!saved_extruder_relative_mode){
-		enquecommand(PSTR("M83"), true);
-	}
-	//retract 45mm/s
-	// A single sprintf may not be faster, but is definitely 20B shorter
-	// than a sequence of commands building the string piece by piece
-	// A snprintf would have been a safer call, but since it is not used
-	// in the whole program, its implementation would bring more bytes to the total size
-	// The behavior of dtostrf 8,3 should be roughly the same as %-0.3
-	sprintf_P(buf, PSTR("G1 E%-0.3f F2700"), e_move);
-	enquecommand(buf, false);
-
-	// Then lift Z axis
-	sprintf_P(buf, PSTR("G1 Z%-0.3f F%-0.3f"), saved_pos[Z_AXIS] + z_move, homing_feedrate[Z_AXIS]); 
-    // At this point the command queue is empty.
-    enquecommand(buf, false);
+    if(e_move)
+    {
+        // First unretract (relative extrusion)
+        if(!saved_extruder_relative_mode){
+            enquecommand(PSTR("M83"), true);
+        }
+        //retract 45mm/s
+        // A single sprintf may not be faster, but is definitely 20B shorter
+        // than a sequence of commands building the string piece by piece
+        // A snprintf would have been a safer call, but since it is not used
+        // in the whole program, its implementation would bring more bytes to the total size
+        // The behavior of dtostrf 8,3 should be roughly the same as %-0.3
+        sprintf_P(buf, PSTR("G1 E%-0.3f F2700"), e_move);
+        enquecommand(buf, false);
+    }
+
+    if(z_move)
+    {
+        // Then lift Z axis
+        sprintf_P(buf, PSTR("G1 Z%-0.3f F%-0.3f"), saved_pos[Z_AXIS] + z_move, homing_feedrate[Z_AXIS]);
+        enquecommand(buf, false);
+    }
+
     // If this call is invoked from the main Arduino loop() function, let the caller know that the command
     // in the command queue is not the original command, but a new one, so it should not be removed from the queue.
     repeatcommand_front();

Firmware/ultralcd.cpp

@@ -1574,7 +1574,7 @@ void lcd_return_to_status()
 //! @brief Pause print, disable nozzle heater, move to park position
 void lcd_pause_print()
 {
-    stop_and_save_print_to_ram(0.0,0.0);
+    stop_and_save_print_to_ram(0.0, -default_retraction);
     lcd_return_to_status();
     isPrintPaused = true;
     if (LcdCommands::Idle == lcd_commands_type)
@@ -6685,7 +6685,7 @@ void lcd_resume_print()
     if (fan_error_selftest()) return; //abort if error persists
 
     isPrintPaused = false;
-    restore_print_from_ram_and_continue(0.0);
+    restore_print_from_ram_and_continue(default_retraction);
     pause_time += (_millis() - start_pause_print); //accumulate time when print is paused for correct statistics calculation
     refresh_cmd_timeout();
     SERIAL_PROTOCOLLNRPGM(MSG_OCTOPRINT_RESUMED); //resume octoprint