fix ADVANCED LPC

MK/Configuration_Feature.h

@@ -268,17 +268,37 @@
 #define THERMAL_PROTECTION_PERIOD    40     // Seconds
 #define THERMAL_PROTECTION_HYSTERESIS 4     // Degrees Celsius
 
-// Whenever an M104 or M109 increases the target temperature the firmware will wait for the
-// WATCH TEMP PERIOD to expire, and if the temperature hasn't increased by WATCH TEMP INCREASE
-// degrees, the machine is halted, requiring a hard reset. This test restarts with any M104/M109,
-//but only if the current temperature is far enough below the target for a reliable test.
-#define WATCH_TEMP_PERIOD  16               // Seconds
-#define WATCH_TEMP_INCREASE 4               // Degrees Celsius
+/**
+ * Whenever an M104 or M109 increases the target temperature the firmware will wait for the
+ * WATCH TEMP PERIOD to expire, and if the temperature hasn't increased by WATCH TEMP INCREASE
+ * degrees, the machine is halted, requiring a hard reset. This test restarts with any M104/M109,
+ * but only if the current temperature is far enough below the target for a reliable test.
+ *
+ * If you get false positives for "Heating failed" increase WATCH TEMP PERIOD and/or decrease WATCH TEMP INCREASE
+ * WATCH TEMP INCREASE should not be below 2.
+ */
+#define WATCH_TEMP_PERIOD  20               // Seconds
+#define WATCH_TEMP_INCREASE 2               // Degrees Celsius
 
+/**
+ * Thermal Protection parameters for the bed are just as above for hotends.
+ */
 //#define THERMAL_PROTECTION_BED 
 
 #define THERMAL_PROTECTION_BED_PERIOD    20 // Seconds
 #define THERMAL_PROTECTION_BED_HYSTERESIS 2 // Degrees Celsius
+
+/**
+ * Whenever an M140 or M190 increases the target temperature the firmware will wait for the
+ * WATCH BED TEMP PERIOD to expire, and if the temperature hasn't increased by WATCH BED TEMP INCREASE
+ * degrees, the machine is halted, requiring a hard reset. This test restarts with any M140/M190,
+ * but only if the current temperature is far enough below the target for a reliable test.
+ *
+ * If you get too many "Heating failed" errors, increase WATCH BED TEMP PERIOD and/or decrease
+ * WATCH BED TEMP INCREASE. (WATCH BED TEMP INCREASE should not be below 2.)
+ */
+#define WATCH_BED_TEMP_PERIOD  60           // Seconds
+#define WATCH_BED_TEMP_INCREASE 2           // Degrees Celsius
 /********************************************************************************/
 
 
@@ -563,9 +583,21 @@
  *****************************************************************************************/
 //#define ADVANCE
 
-#define EXTRUDER_ADVANCE_K .0
+#define EXTRUDER_ADVANCE_K 0.0
 #define D_FILAMENT 1.75
-#define STEPS_PER_CUBIC_MM_E 0.85
+/*****************************************************************************************/
+
+
+/*****************************************************************************************
+ ****************** Extruder Advance 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 ADVANCE_LPC
+#define ADVANCE_LPC_K 75
 /*****************************************************************************************/
 
 

MK/module/MK_Main.cpp

@@ -4185,7 +4185,7 @@ inline void gcode_G28() {
       home_delta_axis();
     deploy_z_probe();
     bed_safe_z = current_position[Z_AXIS];
-    
+
     if (code_seen('X') and code_seen('Y')) {
       // Probe specified X,Y point
       float x = code_seen('X') ? code_value():0.00;
@@ -5356,7 +5356,7 @@ inline void gcode_M92() {
 #endif
 
 /**
- * M104: Set hot end temperature
+ * M104: Set hotend temperature
  */
 inline void gcode_M104() {
   if (setTargetedExtruder(104)) return;
@@ -6368,7 +6368,7 @@ inline void gcode_M226() {
    * M363: SCARA calibration: Move to cal-position PsiB (90 deg calibration - steps per degree)
    */
   inline bool gcode_M363() {
-    ECHO_LM(DB,"Cal: Psi 90 ");
+    ECHO_LM(DB, "Cal: Psi 90 ");
     return SCARA_move_to_cal(50, 90);
   }
 
@@ -7230,6 +7230,17 @@ inline void gcode_M503() {
   }
 #endif
 
+#if ENABLED(ADVANCE_LPC)
+  /**
+   * M905: Set advance factor
+   */
+  inline void gcode_M905() {
+    st_synchronize();
+    if (code_seen('K')) extruder_advance_k = code_value();
+    ECHO_LMV(DB, "Advance factor = ", extruder_advance_k);
+  }
+#endif
+
 #if MB(ALLIGATOR)
   /**
    * M906: Set motor currents
@@ -7787,12 +7798,12 @@ void process_next_command() {
         case 48: // M48 Z-Probe repeatability
           gcode_M48(); break;
       #endif
-      
+
       #if HAS(POWER_CONSUMPTION_SENSOR)
         case 70: // M70 - Power consumption sensor calibration
           gcode_M70(); break;
       #endif
-      
+
       case 75: // Start print timer
         gcode_M75(); break;
 
@@ -7866,14 +7877,14 @@ void process_next_command() {
       case 112: //  M112 Emergency Stop
         gcode_M112(); break;
 
-      case 114: // M114 Report current position
-        gcode_M114(); break;
-
       #if ENABLED(HOST_KEEPALIVE_FEATURE)
         case 113: // M113: Set Host Keepalive interval
           gcode_M113(); break;
       #endif
 
+      case 114: // M114 Report current position
+        gcode_M114(); break;
+
       case 115: // M115 Report capabilities
         gcode_M115(); break;
 
@@ -8090,7 +8101,7 @@ void process_next_command() {
       #endif
 
       #if ENABLED(FILAMENTCHANGEENABLE)
-        case 600: //Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
+        case 600: // Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
           gcode_M600(); break;
       #endif
 
@@ -8104,6 +8115,11 @@ void process_next_command() {
           gcode_M666(); break;
       #endif
 
+      #if ENABLED(ADVANCE_LPC)
+        case 905: // M905 Set advance factor.
+          gcode_M905(); break;
+      #endif
+
       #if MB(ALLIGATOR)
         case 906: // M906 Set motor currents XYZ T0-4 E
           gcode_M906(); break;

MK/module/MK_Main.h

@@ -36,6 +36,10 @@ void idle(
 
 void manage_inactivity(bool ignore_stepper_queue = false);
 
+#if ENABLED(DUAL_X_CARRIAGE)
+  extern bool extruder_duplication_enabled;
+#endif
+
 void FlushSerialRequestResend();
 void ok_to_send();
 
@@ -134,6 +138,10 @@ extern bool axis_known_position[3];
 extern bool axis_homed[3];
 extern float zprobe_zoffset;
 
+#if ENABLED(ADVANCE_LPC)
+  extern int extruder_advance_k;
+#endif
+
 #if HEATER_USES_AD595
   extern float ad595_offset[HOTENDS];
   extern float ad595_gain[HOTENDS];

MK/module/conditionals.h

@@ -505,7 +505,7 @@
    */
   #if ENABLED(ADVANCE)
     #define EXTRUSION_AREA (0.25 * (D_FILAMENT) * (D_FILAMENT) * M_PI)
-    #define STEPS_PER_CUBIC_MM_E (axis_steps_per_unit[E_AXIS + active_extruder] / EXTRUSION_AREA)
+    #define STEPS_PER_CUBIC_MM_E (axis_steps_per_unit[E_AXIS + active_extruder] / (EXTRUSION_AREA))
   #endif
 
   /**

MK/module/language/language.h

@@ -221,7 +221,7 @@
 
 #define SERIAL_HEATER_BED                       "bed"
 #define SERIAL_STOPPED_HEATER                   ", system stopped! Heater_ID: "
-//#define SERIAL_REDUNDANCY                     "Heater switched off. Temperature difference between temp sensors is too high !"
+#define SERIAL_REDUNDANCY                       "Heater switched off. Temperature difference between temp sensors is too high !"
 #define SERIAL_T_HEATING_FAILED                 "Heating failed"
 #define SERIAL_T_THERMAL_RUNAWAY                "Thermal Runaway"
 #define SERIAL_T_MAXTEMP                        "MAXTEMP triggered"

MK/module/language/language_it.h

@@ -151,13 +151,13 @@
 #define MSG_BABYSTEP_Z                      MSG_BABYSTEP " " MSG_Z
 #define MSG_ENDSTOP_ABORT                   "Finecorsa abort."
 #define MSG_HEATING_FAILED_LCD              "Riscaldamento fallito"
-#define MSG_ERR_REDUNDANT_TEMP              "REDUNDANT TEMP ERROR"
-#define MSG_THERMAL_RUNAWAY                 "THERMAL RUNAWAY"
+#define MSG_ERR_REDUNDANT_TEMP              "Err: TEMP RIDONDANTI"
+#define MSG_THERMAL_RUNAWAY                 "TEMP FUORI CONTROLLO"
 #define MSG_AD595                           "AD595 Offset & Gain"
-#define MSG_ERR_MAXTEMP                     "MAXTEMP ERROR"
-#define MSG_ERR_MINTEMP                     "MINTEMP ERROR"
-#define MSG_ERR_MAXTEMP_BED                 "MAXTEMP BED ERROR"
-#define MSG_ERR_MINTEMP_BED                 "MINTEMP BED ERROR"
+#define MSG_ERR_MAXTEMP                     "Err: TEMP MASSIMA"
+#define MSG_ERR_MINTEMP                     "Err: TEMP MINIMA"
+#define MSG_ERR_MAXTEMP_BED                 "Err: TEMP MASSIMA PIATTO"
+#define MSG_ERR_MINTEMP_BED                 "Err: TEMP MINIMA PIATTO"
 #define MSG_END_DAY                         "giorni"
 #define MSG_END_HOUR                        "ore"
 #define MSG_END_MINUTE                      "minuti"

MK/module/motion/planner.cpp

@@ -1126,7 +1126,20 @@ float junction_deviation = 0.1;
     ECHO_SMV(OK, "advance :", block->advance/256);
     ECHO_EMV("advance rate :", block->advance_rate/256);
     */
-  #endif // ADVANCE
+  #elif ENABLED(ADVANCE_LPC) // ADVANCE_LPC
+    // 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) || extruder_advance_k == 0 || bse == allsteps) {
+      block->use_advance_lead = false;
+    }
+    else {
+      block->use_advance_lead = true;
+      block->e_speed_multiplier8 = (block->steps[E_AXIS] << 8) / block->step_event_count;
+    }
+  #endif
 
   calculate_trapezoid_for_block(block, block->entry_speed / block->nominal_speed, safe_speed / block->nominal_speed);
 

MK/module/motion/planner.h

@@ -49,25 +49,32 @@
 // This struct is used when buffering the setup for each linear movement "nominal" values are as specified in
 // the source g-code and may never actually be reached if acceleration management is active.
 typedef struct {
+
+  unsigned char active_driver;              // Selects the active driver
+
   // Fields used by the bresenham algorithm for tracing the line
   unsigned long steps[NUM_AXIS];                      // Step count along each axis
+  unsigned long step_event_count;           // The number of step events required to complete this block
 
   #if ENABLED(COLOR_MIXING_EXTRUDER)
     unsigned long mix_event_count[DRIVER_EXTRUDERS];  // Step count for each stepper in a mixing extruder
   #endif
 
-  unsigned long step_event_count;           // The number of step events required to complete this block
   long accelerate_until;                    // The index of the step event on which to stop acceleration
   long decelerate_after;                    // The index of the step event on which to start decelerating
   long acceleration_rate;                   // The acceleration rate used for acceleration calculation
+
   unsigned char direction_bits;             // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
-  unsigned char active_driver;              // Selects the active driver
 
+  // Advance extrusion
   #if ENABLED(ADVANCE)
     long advance_rate;
     volatile long initial_advance;
     volatile long final_advance;
     float advance;
+  #elif ENABLED(ADVANCE_LPC)
+    bool use_advance_lead;
+    int e_speed_multiplier8;
   #endif
 
   // Fields used by the motion planner to manage acceleration

MK/module/motion/stepper.cpp

@@ -12,16 +12,35 @@
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * stepper.cpp - A singleton object to execute motion plans using stepper motors
+ *
+ * Derived from Grbl
+ * Copyright (c) 2009-2011 Simen Svale Skogsrud
+ *
+ * Grbl is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Grbl is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
+ * You should have received a copy of the GNU General Public License
+ * along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
- * stepper.cpp - stepper motor driver: executes motion plans using stepper motors
  * The timer calculations of this module informed by the 'RepRap cartesian firmware' by Zack Smith
  * and Philipp Tiefenbacher.
  */
@@ -46,8 +65,13 @@ block_t* current_block;  // A pointer to the block currently being traced
 //static makes it impossible to be called from outside of this file by extern.!
 
 // Variables used by The Stepper Driver Interrupt
-static unsigned char out_bits = 0;        // The next stepping-bits to be output
-static unsigned int cleaning_buffer_counter;
+static unsigned char last_direction_bits = 0;  // The next stepping-bits to be output
+static unsigned int cleaning_buffer_counter = 0;
+
+//
+// The direction of a single motor
+//
+FORCE_INLINE bool motor_direction(AxisEnum axis) { return TEST(last_direction_bits, axis); }
 
 #if ENABLED(Z_DUAL_ENDSTOPS)
   static bool performing_homing = false,
@@ -59,10 +83,19 @@ static unsigned int cleaning_buffer_counter;
 static long counter_X, counter_Y, counter_Z, counter_E;
 volatile static unsigned long step_events_completed; // The number of step events executed in the current block
 
-#if ENABLED(ADVANCE)
-  static long advance_rate, advance, final_advance = 0;
-  static long old_advance = 0;
-  static long e_steps[6];
+#if ENABLED(ADVANCE) || ENABLED(ADVANCE_LPC)
+  unsigned char old_OCR0A;
+  #if ENABLED(ADVANCE)
+    static long advance_rate, advance, final_advance = 0;
+    static long old_advance = 0;
+    static long e_steps[6];
+  #elif ENABLED(ADVANCE_LPC)
+    int extruder_advance_k = ADVANCE_LPC_K;
+    volatile int e_steps[EXTRUDERS];
+    static int final_estep_rate;
+    static int current_estep_rate[EXTRUDERS]; // Actual extruder speed [steps/s]
+    static int current_adv_steps[EXTRUDERS];
+  #endif
 #endif
 
 static long acceleration_time, deceleration_time;
@@ -376,9 +409,9 @@ inline void update_endstops() {
     // Head direction in -X axis for CoreXY and CoreXZ bots.
     // If Delta1 == -Delta2, the movement is only in Y or Z axis
     if ((current_block->steps[A_AXIS] != current_block->steps[CORE_AXIS_2]) || (TEST(out_bits, A_AXIS) == TEST(out_bits, CORE_AXIS_2))) {
-      if (TEST(out_bits, X_HEAD))
+      if (motor_direction(X_HEAD))
   #else
-    if (TEST(out_bits, X_AXIS))   // stepping along -X axis (regular Cartesian bot)
+    if (motor_direction(X_AXIS))   // stepping along -X axis (regular Cartesian bot)
   #endif
       { // -direction
         #if ENABLED(DUAL_X_CARRIAGE)
@@ -410,9 +443,9 @@ inline void update_endstops() {
     // Head direction in -Y axis for CoreXY bots.
     // If DeltaX == DeltaY, the movement is only in X axis
     if ((current_block->steps[A_AXIS] != current_block->steps[B_AXIS]) || (TEST(out_bits, A_AXIS) != TEST(out_bits, B_AXIS))) {
-      if (TEST(out_bits, Y_HEAD))
+      if (motor_direction(Y_HEAD))
   #else
-      if (TEST(out_bits, Y_AXIS))   // -direction
+      if (motor_direction(Y_AXIS))   // -direction
   #endif
       { // -direction
         #if HAS(Y_MIN)
@@ -432,9 +465,9 @@ inline void update_endstops() {
     // Head direction in -Z axis for CoreXZ bots.
     // If DeltaX == DeltaZ, the movement is only in X axis
     if ((current_block->steps[A_AXIS] != current_block->steps[C_AXIS]) || (TEST(out_bits, A_AXIS) != TEST(out_bits, C_AXIS))) {
-      if (TEST(out_bits, Z_HEAD))
+      if (motor_direction(Z_HEAD))
   #else
-      if (TEST(out_bits, Z_AXIS))
+      if (motor_direction(Z_AXIS))
   #endif
       { // z -direction
         #if HAS(Z_MIN)
@@ -579,7 +612,7 @@ FORCE_INLINE unsigned short calc_timer(unsigned short step_rate) {
 void set_stepper_direction(bool onlye) {
 
   #define SET_STEP_DIR(AXIS) \
-    if (TEST(out_bits, AXIS ##_AXIS)) { \
+    if (motor_direction(AXIS ##_AXIS)) { \
       AXIS ##_APPLY_DIR(INVERT_## AXIS ##_DIR, false); \
       count_direction[AXIS ##_AXIS] = -1; \
     } \
@@ -595,7 +628,7 @@ void set_stepper_direction(bool onlye) {
   }
 
   #if DISABLED(ADVANCE)
-    if (TEST(out_bits, E_AXIS)) {
+    if (motor_direction(E_AXIS)) {
       REV_E_DIR();
       count_direction[E_AXIS] = -1;
     }
@@ -610,8 +643,11 @@ void set_stepper_direction(bool onlye) {
 // block begins.
 FORCE_INLINE void trapezoid_generator_reset() {
 
-  if (current_block->direction_bits != out_bits) {
-    out_bits = current_block->direction_bits;
+  static int8_t last_driver = -1;
+
+  if (current_block->direction_bits != last_direction_bits || current_block->active_driver != last_driver) {
+    last_direction_bits = current_block->direction_bits;
+    last_driver = current_block->active_driver;
     set_stepper_direction();
   }
 
@@ -630,6 +666,13 @@ FORCE_INLINE void trapezoid_generator_reset() {
   acc_step_rate = current_block->initial_rate;
   acceleration_time = calc_timer(acc_step_rate);
   OCR1A = acceleration_time;
+
+  #if ENABLED(ADVANCE_LPC)
+    if (current_block->use_advance_lead) {
+      current_estep_rate[current_block->active_driver] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
+      final_estep_rate = (current_block->nominal_rate * current_block->e_speed_multiplier8) >> 8;
+    }
+  #endif
 }
 
 // "The Stepper Driver Interrupt" - This timer interrupt is the workhorse.
@@ -698,12 +741,12 @@ ISR(TIMER1_COMPA_vect) {
           counter_E -= current_block->step_event_count;
           #if DISABLED(COLOR_MIXING_EXTRUDER)
             // Don't step E for mixing extruder
-            e_steps[current_block->active_driver] += TEST(out_bits, E_AXIS) ? -1 : 1;
+            e_steps[current_block->active_driver] += motor_direction(E_AXIS) ? -1 : 1;
           #endif
         }
 
         #if ENABLED(COLOR_MIXING_EXTRUDER)
-          long dir = TEST(out_bits, E_AXIS) ? -1 : 1;
+          long dir = motor_direction(E_AXIS) ? -1 : 1;
           for (uint8_t j = 0; j < DRIVER_EXTRUDERS; j++) {
             counter_m[j] += current_block->steps[E_AXIS];
             if (counter_m[j] > 0) {
@@ -712,7 +755,21 @@ ISR(TIMER1_COMPA_vect) {
             }
           }
         #endif // !COLOR_MIXING_EXTRUDER
-      #endif // ADVANCE
+      #elif ENABLED(ADVANCE_LPC) // ADVANCE_LPC
+        counter_E += current_block->steps[E_AXIS];
+        if (counter_E > 0) {
+          counter_E -= current_block->step_event_count;
+          count_position[E_AXIS] += count_direction[E_AXIS];
+          e_steps[current_block->active_driver] += motor_direction(E_AXIS) ? -1 : 1;
+        }
+
+        if (current_block->use_advance_lead) {
+          int delta_adv_steps; // Maybe a char would be enough?
+          delta_adv_steps = (((long)extruder_advance_k * current_estep_rate[current_block->active_driver]) >> 9) - current_adv_steps[current_block->active_driver];
+          e_steps[current_block->active_driver] += delta_adv_steps;
+          current_adv_steps[current_block->active_driver] += delta_adv_steps;
+        }
+      #endif
 
       #define _COUNTER(AXIS) counter_## AXIS
       #define _APPLY_STEP(AXIS) AXIS ##_APPLY_STEP
@@ -746,7 +803,7 @@ ISR(TIMER1_COMPA_vect) {
       STEP_START(X);
       STEP_START(Y);
       STEP_START(Z);
-      #if DISABLED(ADVANCE)
+      #if DISABLED(ADVANCE) && DISABLED(ADVANCE_LPC)
         STEP_START(E);
         #if ENABLED(COLOR_MIXING_EXTRUDER)
           STEP_START_MIXING;
@@ -760,7 +817,7 @@ ISR(TIMER1_COMPA_vect) {
       STEP_END(X);
       STEP_END(Y);
       STEP_END(Z);
-      #if DISABLED(ADVANCE)
+      #if DISABLED(ADVANCE) && DISABLED(ADVANCE_LPC)
         STEP_END(E);
         #if ENABLED(COLOR_MIXING_EXTRUDER)
           STEP_END_MIXING;
@@ -801,8 +858,11 @@ ISR(TIMER1_COMPA_vect) {
         #endif
 
         old_advance = advance >> 8;
+      #elif ENABLED(ADVANCE_LPC) // ADVANCE_LPC
+        if (current_block->use_advance_lead)
+          current_estep_rate[current_block->active_driver] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
+      #endif
 
-      #endif // ADVANCE
     }
     else if (step_events_completed > (unsigned long)current_block->decelerate_after) {
       MultiU24X32toH16(step_rate, deceleration_time, current_block->acceleration_rate);
@@ -836,9 +896,16 @@ ISR(TIMER1_COMPA_vect) {
         #endif
 
         old_advance = advance_whole;
-      #endif //ADVANCE
+      #elif ENABLED(ADVANCE_LPC) // ADVANCE_LPC
+        if (current_block->use_advance_lead)
+          current_estep_rate[current_block->active_driver] = ((unsigned long)step_rate * current_block->e_speed_multiplier8) >> 8;
+      #endif
     }
     else {
+      #if ENABLED(ADVANCE_LPC)
+        if (current_block->use_advance_lead)
+          current_estep_rate[current_block->active_driver] = final_estep_rate;
+      #endif
       OCR1A = OCR1A_nominal;
       // ensure we're running at the correct step rate, even if we just came off an acceleration
       step_loops = step_loops_nominal;
@@ -854,12 +921,25 @@ ISR(TIMER1_COMPA_vect) {
   }
 }
 
-#if ENABLED(ADVANCE)
-  unsigned char old_OCR0A;
+#if ENABLED(ADVANCE) || ENABLED(ADVANCE_LPC)
+
   // Timer interrupt for E. e_steps is set in the main routine;
   // Timer 0 is shared with millies
   ISR(TIMER0_COMPA_vect) {
-    old_OCR0A += 52; // ~10kHz interrupt (250000 / 26 = 9615kHz)
+
+    byte maxesteps = 0;
+    for (unsigned char i = 0; i < EXTRUDERS; i++)
+      if (abs(e_steps[i]) > maxesteps) maxesteps = abs(e_steps[i]);
+
+    if (maxesteps > 3)
+      old_OCR0A += 13; // ~19kHz (250000/13 = 19230 Hz)
+    else if (maxesteps > 2)
+      old_OCR0A += 17; // ~15kHz (250000/17 = 14705 Hz)
+    else if (maxesteps > 1)
+      old_OCR0A += 26; // ~10kHz (250000/26 =  9615 Hz)
+    else
+      old_OCR0A += 52; //  ~5kHz (250000/52 =  4807 Hz)
+
     OCR0A = old_OCR0A;
 
     #define STEP_E_ONCE(INDEX) \
@@ -876,27 +956,25 @@ ISR(TIMER1_COMPA_vect) {
         E## INDEX ##_STEP_WRITE(!INVERT_E_STEP_PIN); \
       }
 
-    // Step all E steppers that have steps, up to 4 steps per interrupt
-    for (uint8_t i = 0; i < 4; i++) {
-      STEP_E_ONCE(0);
-      #if DRIVER_EXTRUDERS > 1
-        STEP_E_ONCE(1);
-        #if DRIVER_EXTRUDERS > 2
-          STEP_E_ONCE(2);
-          #if DRIVER_EXTRUDERS > 3
-            STEP_E_ONCE(3);
-            #if DRIVER_EXTRUDERS > 4
-              STEP_E_ONCE(4);
-              #if DRIVER_EXTRUDERS > 5
-                STEP_E_ONCE(5);
-              #endif // DRIVER_EXTRUDERS > 5
-            #endif // DRIVER_EXTRUDERS > 4
-          #endif // DRIVER_EXTRUDERS > 3
-        #endif // DRIVER_EXTRUDERS > 2
-      #endif // DRIVER_EXTRUDERS > 1
-    }
+    // Step all E steppers that have steps
+    STEP_E_ONCE(0);
+    #if EXTRUDERS > 1
+      STEP_E_ONCE(1);
+      #if EXTRUDERS > 2
+        STEP_E_ONCE(2);
+        #if EXTRUDERS > 3
+          STEP_E_ONCE(3);
+          #if EXTRUDERS > 4
+            STEP_E_ONCE(4);
+            #if EXTRUDERS > 5
+              STEP_E_ONCE(5);
+            #endif
+          #endif
+        #endif
+      #endif
+    #endif
   }
-#endif // ADVANCE
+#endif
 
 void st_init() {
   digipot_init(); //Initialize Digipot Motor Current
@@ -1165,14 +1243,23 @@ void st_init() {
   TCNT1 = 0;
   ENABLE_STEPPER_DRIVER_INTERRUPT();
 
-  #if ENABLED(ADVANCE)
+  #if ENABLED(ADVANCE) || ENABLED(ADVANCE_LPC)
+    #if ENABLED(ADVANCE)
+      e_steps[0] = e_steps[1] = e_steps[2] = e_steps[3] = e_steps[4] = e_steps[5] = 0;
+    #elif ENABLED(ADVANCE_LPC)
+      for (uint8_t i = 0; i < EXTRUDERS; i++) {
+        e_steps[i] = 0;
+        current_adv_steps[i] = 0;
+      }
+    #endif
+      
     #if defined(TCCR0A) && defined(WGM01)
       CBI(TCCR0A, WGM01);
       CBI(TCCR0A, WGM00);
     #endif
-    e_steps[0] = e_steps[1] = e_steps[2] = e_steps[3] = e_steps[4] = e_steps[5] = 0;
     SBI(TIMSK0, OCIE0A);
-  #endif //ADVANCE
+
+  #endif // ADVANCE or ADVANCE_LPC
 
   enable_endstops(true); // Start with endstops active. After homing they can be disabled
   sei();

MK/module/motion/stepper_indirection.h

@@ -232,7 +232,6 @@
     #define NORM_E_DIR()    { switch(current_block->active_driver) { case 1: E1_DIR_WRITE(!INVERT_E1_DIR); break; case 0: E0_DIR_WRITE(!INVERT_E0_DIR); break; }}
     #define REV_E_DIR()     { switch(current_block->active_driver) { case 1: E1_DIR_WRITE( INVERT_E1_DIR); break; case 0: E0_DIR_WRITE( INVERT_E0_DIR); break; }}
   #else
-    extern bool extruder_duplication_enabled;
     #define E_STEP_WRITE(v) { if(extruder_duplication_enabled) { E0_STEP_WRITE(v); E1_STEP_WRITE(v); } else if(current_block->active_driver == 1) { E1_STEP_WRITE(v); } else { E0_STEP_WRITE(v); }}
     #define NORM_E_DIR()    { if(extruder_duplication_enabled) { E0_DIR_WRITE(!INVERT_E0_DIR); E1_DIR_WRITE(!INVERT_E1_DIR); } else if(current_block->active_driver == 1) { E1_DIR_WRITE(!INVERT_E1_DIR); } else { E0_DIR_WRITE(!INVERT_E0_DIR); }}
     #define REV_E_DIR()     { if(extruder_duplication_enabled) { E0_DIR_WRITE( INVERT_E0_DIR); E1_DIR_WRITE( INVERT_E1_DIR); } else if(current_block->active_driver == 1) { E1_DIR_WRITE( INVERT_E1_DIR); } else { E0_DIR_WRITE( INVERT_E0_DIR); }}

MK/module/sanitycheck.h

@@ -391,6 +391,12 @@
     #endif
   #endif
 
+  /**
+   * Advance Extrusion
+   */
+  #if ENABLED(ADVANCE) && ENABLED(ADVANCE_LPC)
+    #error You can enable ADVANCE or ADVANCE_LPC, but not both.
+  #endif
   #if ENABLED(ADVANCE)
     #if DISABLED(EXTRUDER_ADVANCE_K)
       #error DEPENDENCY ERROR: Missing setting EXTRUDER_ADVANCE_K

MK/module/temperature/temperature.cpp

@@ -200,6 +200,11 @@ static void updateTemperaturesFromRawValues();
   millis_t watch_heater_next_ms[HOTENDS] = { 0 };
 #endif
 
+#if ENABLED(THERMAL_PROTECTION_BED)
+  int watch_target_bed_temp = 0;
+  millis_t watch_bed_next_ms = 0;
+#endif
+
 #if DISABLED(SOFT_PWM_SCALE)
   #define SOFT_PWM_SCALE 0
 #endif
@@ -286,12 +291,12 @@ void autotempShutdown() {
         #if HAS(AUTO_FAN)
           if (ms > next_auto_fan_check_ms) {
             checkExtruderAutoFans();
-            next_auto_fan_check_ms = ms + 2500;
+            next_auto_fan_check_ms = ms + 2500UL;
           }
         #endif
 
         if (heating && input > temp) {
-          if (ms > t2 + 5000) {
+          if (ms > t2 + 5000UL) {
             heating = false;
             if (hotend < 0)
               soft_pwm_bed = (bias - d) >> 1;
@@ -304,7 +309,7 @@ void autotempShutdown() {
         }
 
         if (!heating && input < temp) {
-          if (ms > t1 + 5000) {
+          if (ms > t1 + 5000UL) {
             heating = true;
             t2 = ms;
             t_low = t2 - t1;
@@ -699,7 +704,7 @@ void manage_heater() {
     if (ct < max(HEATER_0_MINTEMP, 0.01)) min_temp_error(0);
   #endif
 
-  #if ENABLED(THERMAL_PROTECTION_HOTENDS) || DISABLED(PIDTEMPBED) || HAS(AUTO_FAN)
+  #if ENABLED(THERMAL_PROTECTION_HOTENDS) || ENABLED(THERMAL_PROTECTION_BED) || DISABLED(PIDTEMPBED) || HAS(AUTO_FAN)
     millis_t ms = millis();
   #endif
 
@@ -733,9 +738,27 @@ void manage_heater() {
 
     #endif // THERMAL_PROTECTION_HOTENDS
 
+    // Check if the temperature is failing to increase
+    #if ENABLED(THERMAL_PROTECTION_BED)
+
+      // Is it time to check the bed?
+      if (watch_bed_next_ms && ELAPSED(ms, watch_bed_next_ms)) {
+        // Has it failed to increase enough?
+        if (degBed() < watch_target_bed_temp) {
+          // Stop!
+          _temp_error(-1, PSTR(SERIAL_T_HEATING_FAILED), PSTR(MSG_HEATING_FAILED_LCD));
+        }
+        else {
+          // Start again if the target is still far off
+          start_watching_bed();
+        }
+      }
+
+    #endif // THERMAL_PROTECTION_HOTENDS
+
     #if ENABLED(TEMP_SENSOR_1_AS_REDUNDANT)
       if (fabs(current_temperature[0] - redundant_temperature) > MAX_REDUNDANT_TEMP_SENSOR_DIFF) {
-        _temp_error(0, PSTR(MSG_EXTRUDER_SWITCHED_OFF), PSTR(MSG_ERR_REDUNDANT_TEMP));
+        _temp_error(0, PSTR(SERIAL_REDUNDANCY), PSTR(MSG_ERR_REDUNDANT_TEMP));
       }
     #endif
 
@@ -791,7 +814,7 @@ void manage_heater() {
         soft_pwm_bed = 0;
         WRITE_HEATER_BED(LOW);
       }
-    #else // BED_LIMIT_SWITCHING
+    #else // !PIDTEMPBED && !BED_LIMIT_SWITCHING
       // Check if temperature is within the correct range
       if (current_temperature_bed > BED_MINTEMP && current_temperature_bed < BED_MAXTEMP) {
         soft_pwm_bed = current_temperature_bed < target_temperature_bed ? MAX_BED_POWER >> 1 : 0;
@@ -1226,6 +1249,22 @@ void tp_init() {
   }
 #endif
 
+#if ENABLED(THERMAL_PROTECTION_BED)
+  /**
+   * Start Heating Sanity Check for bed that are below
+   * their target temperature by a configurable margin.
+   * This is called when the temperature is set. (M140, M190)
+   */
+  void start_watching_bed() {
+    if (degBed() < degTargetBed() - (WATCH_BED_TEMP_INCREASE + TEMP_BED_HYSTERESIS + 1)) {
+      watch_target_bed_temp = degBed() + WATCH_BED_TEMP_INCREASE;
+      watch_bed_next_ms = millis() + (WATCH_BED_TEMP_PERIOD) * 1000UL;
+    }
+    else
+      watch_bed_next_ms = 0;
+  }
+#endif
+
 #if ENABLED(THERMAL_PROTECTION_HOTENDS) || ENABLED(THERMAL_PROTECTION_BED)
 
   void thermal_runaway_protection(TRState* state, millis_t* timer, float temperature, float target_temperature, int heater_id, int period_seconds, int hysteresis_degc) {
@@ -1268,7 +1307,7 @@ void tp_init() {
         if (temperature >= tr_target_temperature[heater_index] - hysteresis_degc)
           *timer = millis();
         // If the timer goes too long without a reset, trigger shutdown
-        else if (millis() > *timer + period_seconds * 1000UL)
+        else if (ELAPSED(millis(), *timer + period_seconds * 1000UL))
           *state = TRRunaway;
         break;
       case TRRunaway: