More 2nd extruder implementation. (Not usable)

Advance (not tested)

Marlin/Configuration.h

 
 #define DEFAULT_AXIS_STEPS_PER_UNIT   {78.7402,78.7402,200*8/3,760*1.1}                    // default steps per unit for ultimaker 
 //#define DEFAULT_AXIS_STEPS_PER_UNIT   {40, 40, 3333.92, 67} //sells mendel with v9 extruder
-#define DEFAULT_MAX_FEEDRATE          {500, 500, 5, 200000}    // (mm/sec)    
+#define DEFAULT_MAX_FEEDRATE          {500, 500, 5, 45}    // (mm/sec)    
 #define DEFAULT_MAX_ACCELERATION      {9000,9000,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot.
 
 #define DEFAULT_ACCELERATION          3000    // X, Y, Z and E max acceleration in mm/s^2 for printing moves 
-#define DEFAULT_RETRACT_ACCELERATION  7000   // X, Y, Z and E max acceleration in mm/s^2 for r retracts
+#define DEFAULT_RETRACT_ACCELERATION  3000   // X, Y, Z and E max acceleration in mm/s^2 for r retracts
 
 #define DEFAULT_MINIMUMFEEDRATE       0.0     // minimum feedrate
 #define DEFAULT_MINTRAVELFEEDRATE     0.0

Marlin/planner.cpp

   if (target[Z_AXIS] < position[Z_AXIS]) { block->direction_bits |= (1<<Z_AXIS); }
   if (target[E_AXIS] < position[E_AXIS]) { block->direction_bits |= (1<<E_AXIS); }
   
+  block->active_extruder = extruder;
+  
   //enable active axes
   if(block->steps_x != 0) enable_x();
   if(block->steps_y != 0) enable_y();
   if(block->steps_z != 0) enable_z();
-  if(block->steps_e != 0) enable_e();
-
+  if(extruder == 0) {
+    if(block->steps_e != 0) enable_e();
+  }
+  #if (EXTRUDERS > 1)
+  if(extruder == 1) {
+    if(block->steps_e != 0) enable_e1();
+  }
+  #endif
+  
   float delta_mm[4];
   delta_mm[X_AXIS] = (target[X_AXIS]-position[X_AXIS])/axis_steps_per_unit[X_AXIS];
   delta_mm[Y_AXIS] = (target[Y_AXIS]-position[Y_AXIS])/axis_steps_per_unit[Y_AXIS];
     else {
       long acc_dist = estimate_acceleration_distance(0, block->nominal_rate, block->acceleration_st);
       float advance = (STEPS_PER_CUBIC_MM_E * EXTRUDER_ADVANCE_K) * 
-        (block->speed_e * block->speed_e * EXTRUTION_AREA * EXTRUTION_AREA / 3600.0)*65536;
+        (current_speed[E_AXIS] * current_speed[E_AXIS] * EXTRUTION_AREA * EXTRUTION_AREA / 3600.0)*65536;
       block->advance = advance;
       if(acc_dist == 0) {
         block->advance_rate = 0;

Marlin/planner.h

   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_extruder;            // Selects the active extruder
   #ifdef ADVANCE
-//    long advance_rate;
-//    volatile long initial_advance;
-//    volatile long final_advance;
-//    float advance;
+    long advance_rate;
+    volatile long initial_advance;
+    volatile long final_advance;
+    float advance;
   #endif
 
   // Fields used by the motion planner to manage acceleration

Marlin/stepper.cpp

       }
     #endif //!ADVANCE
     for(int8_t i=0; i < step_loops; i++) { // Take multiple steps per interrupt (For high speed moves) 
-    MSerial.checkRx();
-    /*
+      MSerial.checkRx(); // Check for serial chars. 
+      
+      #ifdef ADVANCE
       counter_e += current_block->steps_e;
       if (counter_e > 0) {
         counter_e -= current_block->step_event_count;
           CRITICAL_SECTION_END;
         }
       }    
-      */
-      /*
       // Do E steps + advance steps
-      CRITICAL_SECTION_START;
       e_steps += ((advance >> 16) - old_advance);
-      CRITICAL_SECTION_END;
       old_advance = advance >> 16;  
-      */
-        
+      #endif //ADVANCE
+      
       counter_x += current_block->steps_x;
       if (counter_x > 0) {
         WRITE(X_STEP_PIN, HIGH);
       OCR1A = timer;
       acceleration_time += timer;
       #ifdef ADVANCE
-        advance += advance_rate;
+        for(int8_t i=0; i < step_loops; i++) {
+          advance += advance_rate;
+        }
       #endif
     } 
     else if (step_events_completed > current_block->decelerate_after) {   
       OCR1A = timer;
       deceleration_time += timer;
       #ifdef ADVANCE
-        advance -= advance_rate;
+        for(int8_t i=0; i < step_loops; i++) {
+          advance -= advance_rate;
+        }
         if(advance < final_advance)
           advance = final_advance;
       #endif //ADVANCE
     else {
       OCR1A = OCR1A_nominal;
     }
-    
+
     // If current block is finished, reset pointer 
     if (step_events_completed >= current_block->step_event_count) {
       current_block = NULL;
   // Timer 0 is shared with millies
   ISR(TIMER0_COMPA_vect)
   {
-    // Critical section needed because Timer 1 interrupt has higher priority. 
-    // The pin set functions are placed on trategic position to comply with the stepper driver timing.
-    WRITE(E_STEP_PIN, LOW);
+    old_OCR0A += 25; // ~10kHz interrupt
+    OCR0A = old_OCR0A;
     // Set E direction (Depends on E direction + advance)
-    if (e_steps < 0) {
-      WRITE(E_DIR_PIN,INVERT_E_DIR);    
-      e_steps++;
-      WRITE(E_STEP_PIN, HIGH);
-    } 
-    if (e_steps > 0) {
-      WRITE(E_DIR_PIN,!INVERT_E_DIR);
-      e_steps--;
-      WRITE(E_STEP_PIN, HIGH);
+    for(unsigned char i=0; i<4;) {
+      WRITE(E_STEP_PIN, LOW);
+      if (e_steps == 0) break;
+      i++;
+      if (e_steps < 0) {
+        WRITE(E_DIR_PIN,INVERT_E_DIR);    
+        e_steps++;
+        WRITE(E_STEP_PIN, HIGH);
+      } 
+      if (e_steps > 0) {
+        WRITE(E_DIR_PIN,!INVERT_E_DIR);
+        e_steps--;
+        WRITE(E_STEP_PIN, HIGH);
+      }
     }
-    old_OCR0A += 25; // 10kHz interrupt
-    OCR0A = old_OCR0A;
   }
 #endif // ADVANCE
 
   ENABLE_STEPPER_DRIVER_INTERRUPT();  
 
   #ifdef ADVANCE
+  #if defined(TCCR0A) && defined(WGM01)
+    TCCR0A &= ~(1<<WGM01);
+    TCCR0A &= ~(1<<WGM00);
+  #endif  
     e_steps = 0;
     TIMSK0 |= (1<<OCIE0A);
   #endif //ADVANCE