diff --git a/.travis.yml b/.travis.yml
index 15b6991ee45ff4a287e883704b17900dc4863196..496b616aa0adeab72e303c1e722665d4b6f7f01e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -76,10 +76,12 @@ script:
- build_marlin
#
# Test 3 extruders on RUMBA (can use any board with >=3 extruders defined)
+ # Include a test for LIN_ADVANCE here also
#
- opt_set MOTHERBOARD BOARD_RUMBA
- opt_set EXTRUDERS 3
- opt_set TEMP_SENSOR_2 1
+ - opt_enable_adv LIN_ADVANCE
- build_marlin
#
# Test PIDTEMPBED
diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 952da0fa7e5ffada0d9b8fd70af66c1abd8edf0a..43b51115ebd99aaaf6835b9aa303b37eaac92cf1 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -445,6 +445,15 @@
#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
+
+#if ENABLED(LIN_ADVANCE)
+ #define LIN_ADVANCE_K 75
+#endif
+
// @section leveling
// Default mesh area is an area with an inset margin on the print area.
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 4fe165e4baf4306c79eb9d32cac97a88343ccdfa..691721fe09f23b3549c1853666619232da447789 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -6475,6 +6475,16 @@ 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();
+ }
+#endif
+
/**
* M907: Set digital trimpot motor current using axis codes X, Y, Z, E, B, S
*/
@@ -7347,6 +7357,12 @@ void process_next_command() {
gcode_M605();
break;
#endif // DUAL_X_CARRIAGE
+
+ #if ENABLED(LIN_ADVANCE)
+ case 905: // M905 Set advance factor.
+ gcode_M905();
+ break;
+ #endif
case 907: // M907 Set digital trimpot motor current using axis codes.
gcode_M907();
diff --git a/Marlin/SanityCheck.h b/Marlin/SanityCheck.h
index a913cb1b0b31c82bca8dac1832b622d83e3825c7..4110d67058a6a59b09f008db1d947e9c9ea9f956 100644
--- a/Marlin/SanityCheck.h
+++ b/Marlin/SanityCheck.h
@@ -351,6 +351,13 @@
#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
*/
@@ -358,7 +365,6 @@
#error "FILAMENT_WIDTH_SENSOR requires a FILWIDTH_PIN to be defined."
#endif
-
/**
* ULTIPANEL encoder
*/
diff --git a/Marlin/planner.cpp b/Marlin/planner.cpp
index bd60d75a1fc7753339adee8e5bfa3f5a54518ec3..699987f159086de4ff30e04c424da9e4934fd695 100644
--- a/Marlin/planner.cpp
+++ b/Marlin/planner.cpp
@@ -1050,7 +1050,23 @@ void Planner::check_axes_activity() {
for (int i = 0; i < NUM_AXIS; i++) previous_speed[i] = current_speed[i];
previous_nominal_speed = block->nominal_speed;
- #if ENABLED(ADVANCE)
+ #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 {
+ block->use_advance_lead = true;
+ block->e_speed_multiplier8 = (block->steps[E_AXIS] << 8) / block->step_event_count;
+ }
+
+ #elif ENABLED(ADVANCE)
+
// Calculate advance rate
if (!bse || (!bsx && !bsy && !bsz)) {
block->advance_rate = 0;
@@ -1069,7 +1085,8 @@ 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);
diff --git a/Marlin/planner.h b/Marlin/planner.h
index 07de37134e5be5596bf0cad2bcfe3d5707f80ea0..51219743edd02f3c51a47efcddf10e56b745abdf 100644
--- a/Marlin/planner.h
+++ b/Marlin/planner.h
@@ -64,7 +64,11 @@ 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;
diff --git a/Marlin/stepper.cpp b/Marlin/stepper.cpp
index f8e8a853c950147e6ffee2a84c291b7bb54e9b78..c9d49cd12c2abf32881bb0d7c32163479635bb86 100644
--- a/Marlin/stepper.cpp
+++ b/Marlin/stepper.cpp
@@ -89,13 +89,24 @@ long Stepper::counter_X = 0,
volatile unsigned long Stepper::step_events_completed = 0; // The number of step events executed in the current block
-#if ENABLED(ADVANCE)
+#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
+
unsigned char Stepper::old_OCR0A;
- long Stepper::final_advance = 0,
- Stepper::old_advance = 0,
- Stepper::e_steps[EXTRUDERS],
- Stepper::advance_rate,
- Stepper::advance;
+ volatile unsigned char Stepper::eISR_Rate = 200; // Keep the ISR at a low rate until needed
+
+ #if ENABLED(LIN_ADVANCE)
+ volatile int Stepper::e_steps[EXTRUDERS];
+ int Stepper::extruder_advance_k = LIN_ADVANCE_K,
+ Stepper::final_estep_rate,
+ Stepper::current_estep_rate[EXTRUDERS],
+ Stepper::current_adv_steps[EXTRUDERS];
+ #else
+ long Stepper::e_steps[EXTRUDERS],
+ Stepper::final_advance = 0,
+ Stepper::old_advance = 0,
+ Stepper::advance_rate,
+ Stepper::advance;
+ #endif
#endif
long Stepper::acceleration_time, Stepper::deceleration_time;
@@ -344,14 +355,32 @@ void Stepper::isr() {
customizedSerial.checkRx(); // Check for serial chars.
#endif
- #if ENABLED(ADVANCE)
+ #if ENABLED(LIN_ADVANCE)
+
+ 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_extruder] += 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_extruder]) >> 9) - current_adv_steps[current_block->active_extruder];
+ e_steps[current_block->active_extruder] += delta_adv_steps;
+ current_adv_steps[current_block->active_extruder] += delta_adv_steps;
+ }
+
+ #elif ENABLED(ADVANCE)
+
counter_E += current_block->steps[E_AXIS];
if (counter_E > 0) {
counter_E -= current_block->step_event_count;
e_steps[current_block->active_extruder] += motor_direction(E_AXIS) ? -1 : 1;
}
- #endif //ADVANCE
+ #endif // ADVANCE or LIN_ADVANCE
+
#define _COUNTER(AXIS) counter_## AXIS
#define _APPLY_STEP(AXIS) AXIS ##_APPLY_STEP
#define _INVERT_STEP_PIN(AXIS) INVERT_## AXIS ##_STEP_PIN
@@ -363,7 +392,7 @@ void Stepper::isr() {
STEP_ADD(X);
STEP_ADD(Y);
STEP_ADD(Z);
- #if DISABLED(ADVANCE)
+ #if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
STEP_ADD(E);
#endif
@@ -377,13 +406,19 @@ void Stepper::isr() {
STEP_IF_COUNTER(X);
STEP_IF_COUNTER(Y);
STEP_IF_COUNTER(Z);
- #if DISABLED(ADVANCE)
+ #if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
STEP_IF_COUNTER(E);
#endif
step_events_completed++;
if (step_events_completed >= current_block->step_event_count) break;
}
+
+ #if ENABLED(LIN_ADVANCE)
+ // If we have esteps to execute, fire the next ISR "now"
+ if (e_steps[current_block->active_extruder]) OCR0A = TCNT0 + 2;
+ #endif
+
// Calculate new timer value
unsigned short timer, step_rate;
if (step_events_completed <= (unsigned long)current_block->accelerate_until) {
@@ -399,7 +434,12 @@ void Stepper::isr() {
OCR1A = timer;
acceleration_time += timer;
- #if ENABLED(ADVANCE)
+ #if ENABLED(LIN_ADVANCE)
+
+ if (current_block->use_advance_lead)
+ current_estep_rate[current_block->active_extruder] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
+
+ #elif ENABLED(ADVANCE)
advance += advance_rate * step_loops;
//NOLESS(advance, current_block->advance);
@@ -408,7 +448,11 @@ void Stepper::isr() {
e_steps[current_block->active_extruder] += ((advance >> 8) - old_advance);
old_advance = advance >> 8;
- #endif //ADVANCE
+ #endif // ADVANCE or LIN_ADVANCE
+
+ #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
+ eISR_Rate = (timer >> 2) / abs(e_steps[current_block->active_extruder]);
+ #endif
}
else if (step_events_completed > (unsigned long)current_block->decelerate_after) {
MultiU24X32toH16(step_rate, deceleration_time, current_block->acceleration_rate);
@@ -424,8 +468,14 @@ void Stepper::isr() {
timer = calc_timer(step_rate);
OCR1A = timer;
deceleration_time += timer;
+
+ #if ENABLED(LIN_ADVANCE)
+
+ if (current_block->use_advance_lead)
+ current_estep_rate[current_block->active_extruder] = ((unsigned long)step_rate * current_block->e_speed_multiplier8) >> 8;
+
+ #elif ENABLED(ADVANCE)
- #if ENABLED(ADVANCE)
advance -= advance_rate * step_loops;
NOLESS(advance, final_advance);
@@ -433,9 +483,24 @@ void Stepper::isr() {
uint32_t advance_whole = advance >> 8;
e_steps[current_block->active_extruder] += advance_whole - old_advance;
old_advance = advance_whole;
- #endif //ADVANCE
+
+ #endif // ADVANCE or LIN_ADVANCE
+
+ #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
+ eISR_Rate = (timer >> 2) / abs(e_steps[current_block->active_extruder]);
+ #endif
}
else {
+
+ #if ENABLED(LIN_ADVANCE)
+
+ if (current_block->use_advance_lead)
+ current_estep_rate[current_block->active_extruder] = final_estep_rate;
+
+ eISR_Rate = (OCR1A_nominal >> 2) / abs(e_steps[current_block->active_extruder]);
+
+ #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;
@@ -451,13 +516,15 @@ void Stepper::isr() {
}
}
-#if ENABLED(ADVANCE)
+#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
+
// Timer interrupt for E. e_steps is set in the main routine;
// Timer 0 is shared with millies
ISR(TIMER0_COMPA_vect) { Stepper::advance_isr(); }
void Stepper::advance_isr() {
- old_OCR0A += 52; // ~10kHz interrupt (250000 / 26 = 9615kHz)
+
+ old_OCR0A += eISR_Rate;
OCR0A = old_OCR0A;
#define STEP_E_ONCE(INDEX) \
@@ -474,22 +541,21 @@ void Stepper::isr() {
E## INDEX ##_STEP_WRITE(!INVERT_E_STEP_PIN); \
}
- // Step all E steppers that have steps, up to 4 steps per interrupt
- for (unsigned char i = 0; i < 4; i++) {
- 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);
- #endif
+ // 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);
#endif
#endif
- }
+ #endif
+
}
-#endif // ADVANCE
+#endif // ADVANCE or LIN_ADVANCE
void Stepper::init() {
@@ -656,14 +722,28 @@ void Stepper::init() {
TCNT1 = 0;
ENABLE_STEPPER_DRIVER_INTERRUPT();
- #if ENABLED(ADVANCE)
+ #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
+
+ #if ENABLED(LIN_ADVANCE)
+
+ for (int i = 0; i < EXTRUDERS; i++) {
+ e_steps[i] = 0;
+ current_adv_steps[i] = 0;
+ }
+
+ #elif ENABLED(ADVANCE)
+
+ for (uint8_t i = 0; i < EXTRUDERS; i++) e_steps[i] = 0;
+
+ #endif
+
#if defined(TCCR0A) && defined(WGM01)
CBI(TCCR0A, WGM01);
CBI(TCCR0A, WGM00);
#endif
- for (uint8_t i = 0; i < EXTRUDERS; i++) e_steps[i] = 0;
SBI(TIMSK0, OCIE0A);
- #endif //ADVANCE
+
+ #endif // ADVANCE or LIN_ADVANCE
endstops.enable(true); // Start with endstops active. After homing they can be disabled
sei();
@@ -1040,3 +1120,14 @@ void Stepper::microstep_readings() {
SERIAL_PROTOCOLLN(digitalRead(E1_MS2_PIN));
#endif
}
+
+#if ENABLED(LIN_ADVANCE)
+
+ void Stepper::advance_M905() {
+ if (code_seen('K')) extruder_advance_k = code_value();
+ SERIAL_ECHO_START;
+ SERIAL_ECHOPAIR("Advance factor: ", extruder_advance_k);
+ SERIAL_EOL;
+ }
+
+#endif // LIN_ADVANCE
diff --git a/Marlin/stepper.h b/Marlin/stepper.h
index 1aebe366c01eeef27226b40fc8ca3ef173a56183..279db1807f46575002b84e458dcf88d4a5708ac4 100644
--- a/Marlin/stepper.h
+++ b/Marlin/stepper.h
@@ -22,7 +22,7 @@
/**
* stepper.h - stepper motor driver: executes motion plans of planner.c using the stepper motors
- * Part of Grbl
+ * Derived from Grbl
*
* Copyright (c) 2009-2011 Simen Svale Skogsrud
*
@@ -90,10 +90,6 @@ class Stepper {
static bool performing_homing;
#endif
- #if ENABLED(ADVANCE)
- static long e_steps[EXTRUDERS];
- #endif
-
private:
static unsigned char last_direction_bits; // The next stepping-bits to be output
@@ -107,10 +103,23 @@ class Stepper {
static long counter_X, counter_Y, counter_Z, counter_E;
static volatile unsigned long step_events_completed; // The number of step events executed in the current block
- #if ENABLED(ADVANCE)
+ #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
static unsigned char old_OCR0A;
- static long advance_rate, advance, old_advance, final_advance;
- #endif
+ static volatile unsigned char eISR_Rate;
+ #if ENABLED(LIN_ADVANCE)
+ static volatile int e_steps[EXTRUDERS];
+ static int extruder_advance_k;
+ static int final_estep_rate;
+ static int current_estep_rate[EXTRUDERS]; // Actual extruder speed [steps/s]
+ static int current_adv_steps[EXTRUDERS]; // The amount of current added esteps due to advance.
+ // i.e., the current amount of pressure applied
+ // to the spring (=filament).
+ #else
+ static long e_steps[EXTRUDERS];
+ static long advance_rate, advance, final_advance;
+ static long old_advance;
+ #endif
+ #endif // ADVANCE or LIN_ADVANCE
static long acceleration_time, deceleration_time;
//unsigned long accelerate_until, decelerate_after, acceleration_rate, initial_rate, final_rate, nominal_rate;
@@ -156,7 +165,7 @@ class Stepper {
static void isr();
- #if ENABLED(ADVANCE)
+ #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
static void advance_isr();
#endif
@@ -246,6 +255,11 @@ class Stepper {
return endstops_trigsteps[axis] / planner.axis_steps_per_mm[axis];
}
+ #if ENABLED(LIN_ADVANCE)
+ void advance_M905();
+ FORCE_INLINE int get_advance_k() { return extruder_advance_k; }
+ #endif
+
private:
static FORCE_INLINE unsigned short calc_timer(unsigned short step_rate) {
@@ -315,6 +329,13 @@ class Stepper {
acc_step_rate = current_block->initial_rate;
acceleration_time = calc_timer(acc_step_rate);
OCR1A = acceleration_time;
+
+ #if ENABLED(LIN_ADVANCE)
+ if (current_block->use_advance_lead) {
+ current_estep_rate[current_block->active_extruder] = ((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
// SERIAL_ECHO_START;
// SERIAL_ECHOPGM("advance :");