Improvements for junction_deviation_mm

- Drop `max_jerk` with `JUNCTION_DEVIATION`
- Add `max_e_jerk_factor` for use by `LIN_ADVANCE`
- Recalculate `max_e_jerk_factor` when `junction_deviation_mm` changes
- Fix LCD editing of `junction_deviation_mm`

Marlin/src/gcode/config/M200-M205.cpp

@@ -134,8 +134,10 @@ void GcodeSuite::M205() {
   #if ENABLED(JUNCTION_DEVIATION)
     if (parser.seen('J')) {
       const float junc_dev = parser.value_linear_units();
-      if (WITHIN(junc_dev, 0.01, 0.3))
+      if (WITHIN(junc_dev, 0.01, 0.3)) {
         planner.junction_deviation_mm = junc_dev;
+        planner.recalculate_max_e_jerk_factor();
+      }
       else {
         SERIAL_ERROR_START();
         SERIAL_ERRORLNPGM("?J out of range (0.01 to 0.3)");
@@ -151,8 +153,6 @@ void GcodeSuite::M205() {
           SERIAL_ECHOLNPGM("WARNING! Low Z Jerk may lead to unwanted pauses.");
       #endif
     }
-  #endif
-  #if DISABLED(JUNCTION_DEVIATION) || ENABLED(LIN_ADVANCE)
     if (parser.seen('E')) planner.max_jerk[E_AXIS] = parser.value_linear_units();
   #endif
 }

Marlin/src/gcode/config/M92.cpp

@@ -39,7 +39,9 @@ void GcodeSuite::M92() {
         const float value = parser.value_per_axis_unit((AxisEnum)(E_AXIS + TARGET_EXTRUDER));
         if (value < 20.0) {
           float factor = planner.axis_steps_per_mm[E_AXIS + TARGET_EXTRUDER] / value; // increase e constants if M92 E14 is given for netfab.
+          #if DISABLED(JUNCTION_DEVIATION)
             planner.max_jerk[E_AXIS] *= factor;
+          #endif
           planner.max_feedrate_mm_s[E_AXIS + TARGET_EXTRUDER] *= factor;
           planner.max_acceleration_steps_per_s2[E_AXIS + TARGET_EXTRUDER] *= factor;
         }

Marlin/src/lcd/ultralcd.cpp

@@ -3752,7 +3752,7 @@ void lcd_quick_feedback(const bool clear_buttons) {
       MENU_BACK(MSG_MOTION);
 
       #if ENABLED(JUNCTION_DEVIATION)
-        MENU_ITEM_EDIT(float3, MSG_JUNCTION_DEVIATION, &planner.junction_deviation_mm, 0.01, 0.3);
+        MENU_ITEM_EDIT_CALLBACK(float43, MSG_JUNCTION_DEVIATION, &planner.junction_deviation_mm, 0.01, 0.3, planner.recalculate_max_e_jerk_factor);
       #else
         MENU_MULTIPLIER_ITEM_EDIT(float3, MSG_VA_JERK, &planner.max_jerk[A_AXIS], 1, 990);
         MENU_MULTIPLIER_ITEM_EDIT(float3, MSG_VB_JERK, &planner.max_jerk[B_AXIS], 1, 990);
@@ -3761,8 +3761,8 @@ void lcd_quick_feedback(const bool clear_buttons) {
         #else
           MENU_MULTIPLIER_ITEM_EDIT(float52sign, MSG_VC_JERK, &planner.max_jerk[C_AXIS], 0.1, 990);
         #endif
-      #endif
         MENU_MULTIPLIER_ITEM_EDIT(float3, MSG_VE_JERK, &planner.max_jerk[E_AXIS], 1, 990);
+      #endif
 
       END_MENU();
     }

Marlin/src/module/configuration_store.cpp

@@ -330,6 +330,10 @@ void MarlinSettings::postprocess() {
     fwretract.refresh_autoretract();
   #endif
 
+  #if ENABLED(JUNCTION_DEVIATION) && ENABLED(LIN_ADVANCE)
+    planner.recalculate_max_e_jerk_factor();
+  #endif
+
   // Refresh steps_to_mm with the reciprocal of axis_steps_per_mm
   // and init stepper.count[], planner.position[] with current_position
   planner.refresh_positioning();
@@ -411,11 +415,13 @@ void MarlinSettings::postprocess() {
     EEPROM_WRITE(planner.travel_acceleration);
     EEPROM_WRITE(planner.min_feedrate_mm_s);
     EEPROM_WRITE(planner.min_travel_feedrate_mm_s);
-    EEPROM_WRITE(planner.max_jerk);
 
     #if ENABLED(JUNCTION_DEVIATION)
+      const float planner_max_jerk[] = { DEFAULT_XJERK, DEFAULT_YJERK, DEFAULT_ZJERK, DEFAULT_EJERK };
+      EEPROM_WRITE(planner_max_jerk);
       EEPROM_WRITE(planner.junction_deviation_mm);
     #else
+      EEPROM_WRITE(planner.max_jerk);
       dummy = 0.02;
       EEPROM_WRITE(dummy);
     #endif
@@ -1008,11 +1014,12 @@ void MarlinSettings::postprocess() {
       EEPROM_READ(planner.travel_acceleration);
       EEPROM_READ(planner.min_feedrate_mm_s);
       EEPROM_READ(planner.min_travel_feedrate_mm_s);
-      EEPROM_READ(planner.max_jerk);
 
       #if ENABLED(JUNCTION_DEVIATION)
+        for (uint8_t q = 4; q--;) EEPROM_READ(dummy);
         EEPROM_READ(planner.junction_deviation_mm);
       #else
+        EEPROM_READ(planner.max_jerk);
         EEPROM_READ(dummy);
       #endif
 
@@ -1724,13 +1731,14 @@ void MarlinSettings::reset(PORTARG_SOLO) {
   planner.travel_acceleration = DEFAULT_TRAVEL_ACCELERATION;
   planner.min_feedrate_mm_s = DEFAULT_MINIMUMFEEDRATE;
   planner.min_travel_feedrate_mm_s = DEFAULT_MINTRAVELFEEDRATE;
+
+  #if ENABLED(JUNCTION_DEVIATION)
+    planner.junction_deviation_mm = JUNCTION_DEVIATION_MM;
+  #else
     planner.max_jerk[X_AXIS] = DEFAULT_XJERK;
     planner.max_jerk[Y_AXIS] = DEFAULT_YJERK;
     planner.max_jerk[Z_AXIS] = DEFAULT_ZJERK;
     planner.max_jerk[E_AXIS] = DEFAULT_EJERK;
-
-  #if ENABLED(JUNCTION_DEVIATION)
-    planner.junction_deviation_mm = JUNCTION_DEVIATION_MM;
   #endif
 
   #if HAS_HOME_OFFSET
@@ -2135,8 +2143,6 @@ void MarlinSettings::reset(PORTARG_SOLO) {
       SERIAL_ECHOPAIR_P(port, " X", LINEAR_UNIT(planner.max_jerk[X_AXIS]));
       SERIAL_ECHOPAIR_P(port, " Y", LINEAR_UNIT(planner.max_jerk[Y_AXIS]));
       SERIAL_ECHOPAIR_P(port, " Z", LINEAR_UNIT(planner.max_jerk[Z_AXIS]));
-    #endif
-    #if DISABLED(JUNCTION_DEVIATION) || ENABLED(LIN_ADVANCE)
       SERIAL_ECHOPAIR_P(port, " E", LINEAR_UNIT(planner.max_jerk[E_AXIS]));
     #endif
 

Marlin/src/module/planner.cpp

@@ -121,11 +121,15 @@ float Planner::max_feedrate_mm_s[XYZE_N],     // (mm/s) M203 XYZE - Max speeds
       Planner::acceleration,                  // (mm/s^2) M204 S - Normal acceleration. DEFAULT ACCELERATION for all printing moves.
       Planner::retract_acceleration,          // (mm/s^2) M204 R - Retract acceleration. Filament pull-back and push-forward while standing still in the other axes
       Planner::travel_acceleration,           // (mm/s^2) M204 T - Travel acceleration. DEFAULT ACCELERATION for all NON printing moves.
-      Planner::max_jerk[XYZE],                // (mm/s^2) M205 XYZE - The largest speed change requiring no acceleration.
       Planner::min_travel_feedrate_mm_s;      // (mm/s) M205 T - Minimum travel feedrate
 
 #if ENABLED(JUNCTION_DEVIATION)
   float Planner::junction_deviation_mm;       // (mm) M205 J
+  #if ENABLED(LIN_ADVANCE)
+    float Planner::max_e_jerk_factor;         // Calculated from junction_deviation_mm
+  #endif
+#else
+  float Planner::max_jerk[XYZE];              // (mm/s^2) M205 XYZE - The largest speed change requiring no acceleration.
 #endif
 
 #if ENABLED(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
@@ -134,6 +138,9 @@ float Planner::max_feedrate_mm_s[XYZE_N],     // (mm/s) M203 XYZE - Max speeds
 
 #if ENABLED(DISTINCT_E_FACTORS)
   uint8_t Planner::last_extruder = 0;     // Respond to extruder change
+  #define _EINDEX (E_AXIS + active_extruder)
+#else
+  #define _EINDEX E_AXIS
 #endif
 
 int16_t Planner::flow_percentage[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(100); // Extrusion factor for each extruder
@@ -2021,6 +2028,13 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
     accel = CEIL((esteps ? acceleration : travel_acceleration) * steps_per_mm);
 
     #if ENABLED(LIN_ADVANCE)
+
+      #if ENABLED(JUNCTION_DEVIATION)
+        #define MAX_E_JERK (max_e_jerk_factor * max_acceleration_mm_per_s2[_EINDEX])
+      #else
+        #define MAX_E_JERK max_jerk[E_AXIS]
+      #endif
+
       /**
        *
        * Use LIN_ADVANCE for blocks if all these are true:
@@ -2051,10 +2065,9 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
         if (block->e_D_ratio > 3.0)
           block->use_advance_lead = false;
         else {
-          const uint32_t max_accel_steps_per_s2 = max_jerk[E_AXIS] / (extruder_advance_K * block->e_D_ratio) * steps_per_mm;
+          const uint32_t max_accel_steps_per_s2 = MAX_E_JERK / (extruder_advance_K * block->e_D_ratio) * steps_per_mm;
           #if ENABLED(LA_DEBUG)
-            if (accel > max_accel_steps_per_s2)
+            if (accel > max_accel_steps_per_s2) SERIAL_ECHOLNPGM("Acceleration limited.");
-              SERIAL_ECHOLNPGM("Acceleration limited.");
           #endif
           NOMORE(accel, max_accel_steps_per_s2);
         }
@@ -2459,10 +2472,7 @@ bool Planner::buffer_segment(const float &a, const float &b, const float &c, con
 
 void Planner::_set_position_mm(const float &a, const float &b, const float &c, const float &e) {
   #if ENABLED(DISTINCT_E_FACTORS)
-    #define _EINDEX (E_AXIS + active_extruder)
     last_extruder = active_extruder;
-  #else
-    #define _EINDEX E_AXIS
   #endif
   position[A_AXIS] = LROUND(a * axis_steps_per_mm[A_AXIS]),
   position[B_AXIS] = LROUND(b * axis_steps_per_mm[B_AXIS]),

Marlin/src/module/planner.h

@@ -195,21 +195,25 @@ class Planner {
                                                       // May be auto-adjusted by a filament width sensor
     #endif
 
-    static uint32_t max_acceleration_steps_per_s2[XYZE_N],
+    static uint32_t max_acceleration_mm_per_s2[XYZE_N],    // (mm/s^2) M201 XYZE
-                    max_acceleration_mm_per_s2[XYZE_N], // Use M201 to override
+                    max_acceleration_steps_per_s2[XYZE_N], // (steps/s^2) Derived from mm_per_s2
-                    min_segment_time_us; // Use 'M205 B<µs>' to override
+                    min_segment_time_us;                   // (µs) M205 B
-    static float max_feedrate_mm_s[XYZE_N],         // Max speeds in mm per second
+    static float max_feedrate_mm_s[XYZE_N],     // (mm/s) M203 XYZE - Max speeds
-                 axis_steps_per_mm[XYZE_N],
+                 axis_steps_per_mm[XYZE_N],     // (steps) M92 XYZE - Steps per millimeter
-                 steps_to_mm[XYZE_N],
+                 steps_to_mm[XYZE_N],           // (mm) Millimeters per step
-                 min_feedrate_mm_s,
+                 min_feedrate_mm_s,             // (mm/s) M205 S - Minimum linear feedrate
-                 acceleration,         // Normal acceleration mm/s^2  DEFAULT ACCELERATION for all printing moves. M204 SXXXX
+                 acceleration,                  // (mm/s^2) M204 S - Normal acceleration. DEFAULT ACCELERATION for all printing moves.
-                 retract_acceleration, // Retract acceleration mm/s^2 filament pull-back and push-forward while standing still in the other axes M204 TXXXX
+                 retract_acceleration,          // (mm/s^2) M204 R - Retract acceleration. Filament pull-back and push-forward while standing still in the other axes
-                 travel_acceleration,  // Travel acceleration mm/s^2  DEFAULT ACCELERATION for all NON printing moves. M204 MXXXX
+                 travel_acceleration,           // (mm/s^2) M204 T - Travel acceleration. DEFAULT ACCELERATION for all NON printing moves.
-                 max_jerk[XYZE],       // The largest speed change requiring no acceleration
+                 min_travel_feedrate_mm_s;      // (mm/s) M205 T - Minimum travel feedrate
-                 min_travel_feedrate_mm_s;
 
     #if ENABLED(JUNCTION_DEVIATION)
-      static float junction_deviation_mm; // Initialized by EEPROM
+      static float junction_deviation_mm;       // (mm) M205 J
+      #if ENABLED(LIN_ADVANCE)
+        static float max_e_jerk_factor;         // Calculated from junction_deviation_mm
+      #endif
+    #else
+      static float max_jerk[XYZE];              // (mm/s^2) M205 XYZE - The largest speed change requiring no acceleration.
     #endif
 
     #if HAS_LEVELING
@@ -745,6 +749,14 @@ class Planner {
       static void autotemp_M104_M109();
     #endif
 
+    #if ENABLED(JUNCTION_DEVIATION)
+      FORCE_INLINE static void recalculate_max_e_jerk_factor() {
+        #if ENABLED(LIN_ADVANCE)
+          max_e_jerk_factor = SQRT(SQRT(0.5) * junction_deviation_mm) * RECIPROCAL(1.0 - SQRT(0.5));
+        #endif
+      }
+    #endif
+
   private:
 
     /**