Patch LIN_ADVANCE for style and forward-compatibility

Marlin/Configuration_adv.h

@@ -452,13 +452,13 @@
   #define D_FILAMENT 2.85
 #endif
 
-//Implementation of a linear pressure control
-//Assumption: advance = k * (delta velocity)
-//K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
-#define LIN_ADVANCE
+// Implementation of a linear pressure control
+// Assumption: advance = k * (delta velocity)
+// K=0 means advance disabled. A good value for a gregs wade extruder will be around K=75
+//#define LIN_ADVANCE
 
 #if ENABLED(LIN_ADVANCE)
-  #define LIN_K 75
+  #define LIN_ADVANCE_K 75
 #endif
 
 // @section extras

Marlin/Marlin.h

@@ -134,6 +134,10 @@ void idle(
 
 void manage_inactivity(bool ignore_stepper_queue = false);
 
+#if ENABLED(DUAL_X_CARRIAGE)
+  extern bool extruder_duplication_enabled;
+#endif
+
 #if ENABLED(DUAL_X_CARRIAGE) && HAS_X_ENABLE && HAS_X2_ENABLE
   #define  enable_x() do { X_ENABLE_WRITE( X_ENABLE_ON); X2_ENABLE_WRITE( X_ENABLE_ON); } while (0)
   #define disable_x() do { X_ENABLE_WRITE(!X_ENABLE_ON); X2_ENABLE_WRITE(!X_ENABLE_ON); axis_known_position[X_AXIS] = false; } while (0)

Marlin/Marlin_main.cpp

@@ -6155,13 +6155,13 @@ inline void gcode_M503() {
 #endif // DUAL_X_CARRIAGE
 
 #if ENABLED(LIN_ADVANCE)
-/**
- * M905: Set advance factor
- */
-inline void gcode_M905() {
-  stepper.synchronize();
-  stepper.advance_M905();
-}
+  /**
+   * M905: Set advance factor
+   */
+  inline void gcode_M905() {
+    stepper.synchronize();
+    stepper.advance_M905();
+  }
 #endif
 
 /**

Marlin/SanityCheck.h

@@ -306,14 +306,20 @@
 
 #endif // AUTO_BED_LEVELING_FEATURE
 
+/**
+ * Advance Extrusion
+ */
+#if ENABLED(ADVANCE) && ENABLED(LIN_ADVANCE)
+  #error You can enable ADVANCE or LIN_ADVANCE, but not both.
+#endif
+
 /**
  * Filament Width Sensor
  */
 #if ENABLED(FILAMENT_WIDTH_SENSOR) && !HAS_FILAMENT_WIDTH_SENSOR
   #error FILAMENT_WIDTH_SENSOR requires a FILWIDTH_PIN to be defined.
 #endif
 
-
 /**
  * ULTIPANEL encoder
  */

Marlin/planner.cpp

@@ -966,24 +966,28 @@ void Planner::check_axes_activity() {
   // the maximum junction speed and may always be ignored for any speed reduction checks.
   block->nominal_length_flag = (block->nominal_speed <= v_allowable);
   block->recalculate_flag = true; // Always calculate trapezoid for new block
-
-  #ifdef LIN_ADVANCE
-    //bse = allsteps: A problem occures if there is a very tiny move before a retract.
-    //In this case, the retract and the move will be executed together. This leads to an enormus amount advance steps due to a hughe e_acceleration.
-    //The math is correct, but you don't want a retract move done with advance! This situation has to be filtered out.
-    if ((!bse || (!bsx && !bsy && !bsz)) || (stepper.get_advance_k() == 0) || (bse == allsteps)) {
+
+  // Update previous path unit_vector and nominal speed
+  for (int i = 0; i < NUM_AXIS; i++) previous_speed[i] = current_speed[i];
+  previous_nominal_speed = block->nominal_speed;
+
+  #if ENABLED(LIN_ADVANCE)
+
+    // bse == allsteps: A problem occurs when there's a very tiny move before a retract.
+    // In this case, the retract and the move will be executed together.
+    // This leads to an enormous number of advance steps due to a huge e_acceleration.
+    // The math is correct, but you don't want a retract move done with advance!
+    // So this situation is filtered out here.
+    if (!bse || (!bsx && !bsy && !bsz) || stepper.get_advance_k() == 0 || bse == allsteps) {
       block->use_advance_lead = false;
-    } else {
+    }
+    else {
       block->use_advance_lead = true;
       block->e_speed_multiplier8 = (block->steps[E_AXIS] << 8) / block->step_event_count;
     }
-  #endif
 
-  // Update previous path unit_vector and nominal speed
-  for (int i = 0; i < NUM_AXIS; i++) previous_speed[i] = current_speed[i];
-  previous_nominal_speed = block->nominal_speed;
+  #elif ENABLED(ADVANCE)
 
-  #if ENABLED(ADVANCE)
     // Calculate advance rate
     if (!bse || (!bsx && !bsy && !bsz)) {
       block->advance_rate = 0;
@@ -1002,7 +1006,8 @@ void Planner::check_axes_activity() {
      SERIAL_ECHOPGM("advance rate :");
      SERIAL_ECHOLN(block->advance_rate/256.0);
      */
-  #endif // ADVANCE
+
+  #endif // ADVANCE or LIN_ADVANCE
 
   calculate_trapezoid_for_block(block, block->entry_speed / block->nominal_speed, safe_speed / block->nominal_speed);
 

Marlin/planner.h

@@ -64,16 +64,16 @@ typedef struct {
 
   unsigned char direction_bits;             // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
 
-  #if ENABLED(ADVANCE)
+  // Advance extrusion
+  #if ENABLED(LIN_ADVANCE)
+    bool use_advance_lead;
+    int e_speed_multiplier8; // Factorised by 2^8 to avoid float
+  #elif ENABLED(ADVANCE)
     long advance_rate;
     volatile long initial_advance;
     volatile long final_advance;
     float advance;
   #endif
-  #ifdef LIN_ADVANCE
-    bool use_advance_lead;
-    int e_speed_multiplier8; //factorised by 2^8 to avoid float
-  #endif
 
   // Fields used by the motion planner to manage acceleration
   float nominal_speed;                               // The nominal speed for this block in mm/sec
@@ -169,10 +169,6 @@ class Planner {
       static long axis_segment_time[2][3] = { {MAX_FREQ_TIME + 1, 0, 0}, {MAX_FREQ_TIME + 1, 0, 0} };
     #endif
 
-    #if ENABLED(DUAL_X_CARRIAGE)
-      extern bool extruder_duplication_enabled;
-    #endif
-
   public:
 
     Planner();