From a448cedbc57c9ea68c3f264115a8e83d694b0c2c Mon Sep 17 00:00:00 2001
From: Sebastianv650 <sebastian_v650@kabelmail.de>
Date: Sat, 8 Oct 2016 18:13:04 +0200
Subject: [PATCH] LIN_ADVANCE bug fix and optimization
.) long to int: Extruder stalls at 10kHz / 20kHz step limits with long.
.) Take the delta_adv_steps calculation out of the step_loops loop. Wasted calculation performance if done inside.
.) >> 2 replaced by 3: Is divide by 8. Reason: Timer 0 runs at 16/8=2MHz, Timer 1 at 16/64=0.25MHz. ==> 2/0.25=8.
---
Marlin/stepper.cpp | 43 +++++++++++++++++++++----------------------
Marlin/stepper.h | 2 +-
2 files changed, 22 insertions(+), 23 deletions(-)
diff --git a/Marlin/stepper.cpp b/Marlin/stepper.cpp
index f2800ebe56..7889b8a883 100644
--- a/Marlin/stepper.cpp
+++ b/Marlin/stepper.cpp
@@ -95,7 +95,7 @@ volatile uint32_t Stepper::step_events_completed = 0; // The number of step even
volatile unsigned char Stepper::eISR_Rate = 200; // Keep the ISR at a low rate until needed
#if ENABLED(LIN_ADVANCE)
- volatile long Stepper::e_steps[E_STEPPERS];
+ volatile int Stepper::e_steps[E_STEPPERS];
int Stepper::extruder_advance_k = LIN_ADVANCE_K,
Stepper::final_estep_rate,
Stepper::current_estep_rate[E_STEPPERS],
@@ -391,7 +391,7 @@ void Stepper::isr() {
#if ENABLED(MIXING_EXTRUDER)
// Step mixing steppers proportionally
- bool dir = motor_direction(E_AXIS);
+ const bool dir = motor_direction(E_AXIS);
MIXING_STEPPERS_LOOP(j) {
counter_m[j] += current_block->steps[E_AXIS];
if (counter_m[j] > 0) {
@@ -401,22 +401,6 @@ void Stepper::isr() {
}
#endif
- if (current_block->use_advance_lead) {
- int delta_adv_steps = (((long)extruder_advance_k * current_estep_rate[TOOL_E_INDEX]) >> 9) - current_adv_steps[TOOL_E_INDEX];
- #if ENABLED(MIXING_EXTRUDER)
- // Mixing extruders apply advance lead proportionally
- MIXING_STEPPERS_LOOP(j) {
- int steps = delta_adv_steps * current_block->step_event_count / current_block->mix_event_count[j];
- e_steps[j] += steps;
- current_adv_steps[j] += steps;
- }
- #else
- // For most extruders, advance the single E stepper
- e_steps[TOOL_E_INDEX] += delta_adv_steps;
- current_adv_steps[TOOL_E_INDEX] += delta_adv_steps;
- #endif
- }
-
#elif ENABLED(ADVANCE)
// Always count the unified E axis
@@ -432,7 +416,7 @@ void Stepper::isr() {
#if ENABLED(MIXING_EXTRUDER)
// Step mixing steppers proportionally
- bool dir = motor_direction(E_AXIS);
+ const bool dir = motor_direction(E_AXIS);
MIXING_STEPPERS_LOOP(j) {
counter_m[j] += current_block->steps[E_AXIS];
if (counter_m[j] > 0) {
@@ -536,6 +520,21 @@ void Stepper::isr() {
}
}
+ #if ENABLED(LIN_ADVANCE)
+ if (current_block->use_advance_lead) {
+ int delta_adv_steps = (((long)extruder_advance_k * current_estep_rate[TOOL_E_INDEX]) >> 9) - current_adv_steps[TOOL_E_INDEX];
+ current_adv_steps[TOOL_E_INDEX] += delta_adv_steps;
+ #if ENABLED(MIXING_EXTRUDER)
+ // Mixing extruders apply advance lead proportionally
+ MIXING_STEPPERS_LOOP(j)
+ e_steps[j] += delta_adv_steps * current_block->step_event_count / current_block->mix_event_count[j];
+ #else
+ // For most extruders, advance the single E stepper
+ e_steps[TOOL_E_INDEX] += delta_adv_steps;
+ #endif
+ }
+ #endif
+
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
// If we have esteps to execute, fire the next advance_isr "now"
if (e_steps[TOOL_E_INDEX]) OCR0A = TCNT0 + 2;
@@ -593,7 +592,7 @@ void Stepper::isr() {
#endif // ADVANCE or LIN_ADVANCE
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
- eISR_Rate = (timer >> 2) * step_loops / abs(e_steps[TOOL_E_INDEX]);
+ eISR_Rate = (timer >> 3) * step_loops / abs(e_steps[TOOL_E_INDEX]); //>> 3 is divide by 8. Reason: Timer 0 runs at 16/8=2MHz, Timer 1 at 16/64=0.25MHz. ==> 2/0.25=8.
#endif
}
else if (step_events_completed > (uint32_t)current_block->decelerate_after) {
@@ -643,7 +642,7 @@ void Stepper::isr() {
#endif // ADVANCE or LIN_ADVANCE
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
- eISR_Rate = (timer >> 2) * step_loops / abs(e_steps[TOOL_E_INDEX]);
+ eISR_Rate = (timer >> 3) * step_loops / abs(e_steps[TOOL_E_INDEX]);
#endif
}
else {
@@ -653,7 +652,7 @@ void Stepper::isr() {
if (current_block->use_advance_lead)
current_estep_rate[TOOL_E_INDEX] = final_estep_rate;
- eISR_Rate = (OCR1A_nominal >> 2) * step_loops_nominal / abs(e_steps[TOOL_E_INDEX]);
+ eISR_Rate = (OCR1A_nominal >> 3) * step_loops_nominal / abs(e_steps[TOOL_E_INDEX]);
#endif
diff --git a/Marlin/stepper.h b/Marlin/stepper.h
index 3e31f82d19..5b6b144f09 100644
--- a/Marlin/stepper.h
+++ b/Marlin/stepper.h
@@ -108,7 +108,7 @@ class Stepper {
static unsigned char old_OCR0A;
static volatile unsigned char eISR_Rate;
#if ENABLED(LIN_ADVANCE)
- static volatile long e_steps[E_STEPPERS];
+ static volatile int e_steps[E_STEPPERS];
static int extruder_advance_k;
static int final_estep_rate;
static int current_estep_rate[E_STEPPERS]; // Actual extruder speed [steps/s]