--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/planner.cpp Sat Nov 07 13:23:07 2015 +0100
@@ -0,0 +1,815 @@
+/*
+ planner.c - buffers movement commands and manages the acceleration profile plan
+ Part of 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/>.
+*/
+
+/* The ring buffer implementation gleaned from the wiring_serial library by David A. Mellis. */
+
+/*
+ Reasoning behind the mathematics in this module (in the key of 'Mathematica'):
+
+ s == speed, a == acceleration, t == time, d == distance
+
+ Basic definitions:
+
+ Speed[s_, a_, t_] := s + (a*t)
+ Travel[s_, a_, t_] := Integrate[Speed[s, a, t], t]
+
+ Distance to reach a specific speed with a constant acceleration:
+
+ Solve[{Speed[s, a, t] == m, Travel[s, a, t] == d}, d, t]
+ d -> (m^2 - s^2)/(2 a) --> estimate_acceleration_distance()
+
+ Speed after a given distance of travel with constant acceleration:
+
+ Solve[{Speed[s, a, t] == m, Travel[s, a, t] == d}, m, t]
+ m -> Sqrt[2 a d + s^2]
+
+ DestinationSpeed[s_, a_, d_] := Sqrt[2 a d + s^2]
+
+ When to start braking (di) to reach a specified destionation speed (s2) after accelerating
+ from initial speed s1 without ever stopping at a plateau:
+
+ Solve[{DestinationSpeed[s1, a, di] == DestinationSpeed[s2, a, d - di]}, di]
+ di -> (2 a d - s1^2 + s2^2)/(4 a) --> intersection_distance()
+
+ IntersectionDistance[s1_, s2_, a_, d_] := (2 a d - s1^2 + s2^2)/(4 a)
+*/
+
+#include "Marlin.h"
+#include "planner.h"
+#include "stepper.h"
+#include "temperature.h"
+#include "ultralcd.h"
+#include "language.h"
+#include "led.h"
+
+//===========================================================================
+//=============================public variables ============================
+//===========================================================================
+
+unsigned long minsegmenttime;
+float max_feedrate[4]; // set the max speeds
+float axis_steps_per_unit[4];
+unsigned long max_acceleration_units_per_sq_second[4]; // Use M201 to override by software
+float minimumfeedrate;
+float acceleration; // Normal acceleration mm/s^2 THIS IS THE DEFAULT ACCELERATION for all moves. M204 SXXXX
+float retract_acceleration; // mm/s^2 filament pull-pack and push-forward while standing still in the other axis M204 TXXXX
+float max_xy_jerk; //speed than can be stopped at once, if i understand correctly.
+float max_z_jerk;
+float max_e_jerk;
+float mintravelfeedrate;
+unsigned long axis_steps_per_sqr_second[NUM_AXIS];
+
+// The current position of the tool in absolute steps
+long position[4]; //rescaled from extern when axis_steps_per_unit are changed by gcode
+static float previous_speed[4]; // Speed of previous path line segment
+static float previous_nominal_speed; // Nominal speed of previous path line segment
+
+extern volatile int extrudemultiply; // Sets extrude multiply factor (in percent)
+
+#ifdef AUTOTEMP
+ float autotemp_max=250;
+ float autotemp_min=210;
+ float autotemp_factor=0.1;
+ bool autotemp_enabled=false;
+#endif
+
+//===========================================================================
+//=================semi-private variables, used in inline functions =====
+//===========================================================================
+block_t block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instfructions
+volatile unsigned char block_buffer_head; // Index of the next block to be pushed
+volatile unsigned char block_buffer_tail; // Index of the block to process now
+
+//===========================================================================
+//=============================private variables ============================
+//===========================================================================
+#ifdef PREVENT_DANGEROUS_EXTRUDE
+ bool allow_cold_extrude=false;
+#endif
+#ifdef XY_FREQUENCY_LIMIT
+ // Used for the frequency limit
+ static unsigned char old_direction_bits = 0; // Old direction bits. Used for speed calculations
+ static long x_segment_time[3]={0,0,0}; // Segment times (in us). Used for speed calculations
+ static long y_segment_time[3]={0,0,0};
+#endif
+
+// Returns the index of the next block in the ring buffer
+// NOTE: Removed modulo (%) operator, which uses an expensive divide and multiplication.
+static int8_t next_block_index(int8_t block_index) {
+ block_index++;
+ if (block_index == BLOCK_BUFFER_SIZE) { block_index = 0; }
+ return(block_index);
+}
+
+
+// Returns the index of the previous block in the ring buffer
+static int8_t prev_block_index(int8_t block_index) {
+ if (block_index == 0) { block_index = BLOCK_BUFFER_SIZE; }
+ block_index--;
+ return(block_index);
+}
+
+//===========================================================================
+//=============================functions ============================
+//===========================================================================
+
+// Calculates the distance (not time) it takes to accelerate from initial_rate to target_rate using the
+// given acceleration:
+FORCE_INLINE float estimate_acceleration_distance(float initial_rate, float target_rate, float acceleration)
+{
+ if (acceleration!=0) {
+ return((target_rate*target_rate-initial_rate*initial_rate)/
+ (2.0*acceleration));
+ }
+ else {
+ return 0.0; // acceleration was 0, set acceleration distance to 0
+ }
+}
+
+// This function gives you the point at which you must start braking (at the rate of -acceleration) if
+// you started at speed initial_rate and accelerated until this point and want to end at the final_rate after
+// a total travel of distance. This can be used to compute the intersection point between acceleration and
+// deceleration in the cases where the trapezoid has no plateau (i.e. never reaches maximum speed)
+
+FORCE_INLINE float intersection_distance(float initial_rate, float final_rate, float acceleration, float distance)
+{
+ if (acceleration!=0) {
+ return((2.0*acceleration*distance-initial_rate*initial_rate+final_rate*final_rate)/
+ (4.0*acceleration) );
+ }
+ else {
+ return 0.0; // acceleration was 0, set intersection distance to 0
+ }
+}
+
+// Calculates trapezoid parameters so that the entry- and exit-speed is compensated by the provided factors.
+
+void calculate_trapezoid_for_block(block_t *block, float entry_factor, float exit_factor) {
+ unsigned long initial_rate = ceil(block->nominal_rate*entry_factor); // (step/min)
+ unsigned long final_rate = ceil(block->nominal_rate*exit_factor); // (step/min)
+
+ // Limit minimal step rate (Otherwise the timer will overflow.)
+ if(initial_rate <120) {initial_rate=120; }
+ if(final_rate < 120) {final_rate=120; }
+
+ long acceleration = block->acceleration_st;
+ int32_t accelerate_steps =
+ ceil(estimate_acceleration_distance(block->initial_rate, block->nominal_rate, acceleration));
+ int32_t decelerate_steps =
+ floor(estimate_acceleration_distance(block->nominal_rate, block->final_rate, -acceleration));
+
+ // Calculate the size of Plateau of Nominal Rate.
+ int32_t plateau_steps = block->step_event_count-accelerate_steps-decelerate_steps;
+
+ // Is the Plateau of Nominal Rate smaller than nothing? That means no cruising, and we will
+ // have to use intersection_distance() to calculate when to abort acceleration and start braking
+ // in order to reach the final_rate exactly at the end of this block.
+ if (plateau_steps < 0) {
+ accelerate_steps = ceil(
+ intersection_distance(block->initial_rate, block->final_rate, acceleration, block->step_event_count));
+ accelerate_steps = max(accelerate_steps,0); // Check limits due to numerical round-off
+ accelerate_steps = min(accelerate_steps,block->step_event_count);
+ plateau_steps = 0;
+ }
+
+ #ifdef ADVANCE
+ volatile long initial_advance = block->advance*entry_factor*entry_factor;
+ volatile long final_advance = block->advance*exit_factor*exit_factor;
+ #endif // ADVANCE
+
+ // block->accelerate_until = accelerate_steps;
+ // block->decelerate_after = accelerate_steps+plateau_steps;
+ CRITICAL_SECTION_START; // Fill variables used by the stepper in a critical section
+ if(block->busy == false) { // Don't update variables if block is busy.
+ block->accelerate_until = accelerate_steps;
+ block->decelerate_after = accelerate_steps+plateau_steps;
+ block->initial_rate = initial_rate;
+ block->final_rate = final_rate;
+ #ifdef ADVANCE
+ block->initial_advance = initial_advance;
+ block->final_advance = final_advance;
+ #endif //ADVANCE
+ }
+ CRITICAL_SECTION_END;
+}
+
+// Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
+// acceleration within the allotted distance.
+FORCE_INLINE float max_allowable_speed(float acceleration, float target_velocity, float distance) {
+ return sqrt(target_velocity*target_velocity-2*acceleration*distance);
+}
+
+// "Junction jerk" in this context is the immediate change in speed at the junction of two blocks.
+// This method will calculate the junction jerk as the euclidean distance between the nominal
+// velocities of the respective blocks.
+//inline float junction_jerk(block_t *before, block_t *after) {
+// return sqrt(
+// pow((before->speed_x-after->speed_x), 2)+pow((before->speed_y-after->speed_y), 2));
+//}
+
+
+// The kernel called by planner_recalculate() when scanning the plan from last to first entry.
+void planner_reverse_pass_kernel(block_t *previous, block_t *current, block_t *next) {
+ if(!current) { return; }
+
+ if (next) {
+ // If entry speed is already at the maximum entry speed, no need to recheck. Block is cruising.
+ // If not, block in state of acceleration or deceleration. Reset entry speed to maximum and
+ // check for maximum allowable speed reductions to ensure maximum possible planned speed.
+ if (current->entry_speed != current->max_entry_speed) {
+
+ // If nominal length true, max junction speed is guaranteed to be reached. Only compute
+ // for max allowable speed if block is decelerating and nominal length is false.
+ if ((!current->nominal_length_flag) && (current->max_entry_speed > next->entry_speed)) {
+ current->entry_speed = min( current->max_entry_speed,
+ max_allowable_speed(-current->acceleration,next->entry_speed,current->millimeters));
+ } else {
+ current->entry_speed = current->max_entry_speed;
+ }
+ current->recalculate_flag = true;
+
+ }
+ } // Skip last block. Already initialized and set for recalculation.
+}
+
+// planner_recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
+// implements the reverse pass.
+void planner_reverse_pass() {
+ uint8_t block_index = block_buffer_head;
+ if(((block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1)) > 3) {
+ block_index = (block_buffer_head - 3) & (BLOCK_BUFFER_SIZE - 1);
+ block_t *block[3] = { NULL, NULL, NULL };
+ while(block_index != block_buffer_tail) {
+ block_index = prev_block_index(block_index);
+ block[2]= block[1];
+ block[1]= block[0];
+ block[0] = &block_buffer[block_index];
+ planner_reverse_pass_kernel(block[0], block[1], block[2]);
+ }
+ }
+}
+
+// The kernel called by planner_recalculate() when scanning the plan from first to last entry.
+void planner_forward_pass_kernel(block_t *previous, block_t *current, block_t *next) {
+ if(!previous) { return; }
+
+ // If the previous block is an acceleration block, but it is not long enough to complete the
+ // full speed change within the block, we need to adjust the entry speed accordingly. Entry
+ // speeds have already been reset, maximized, and reverse planned by reverse planner.
+ // If nominal length is true, max junction speed is guaranteed to be reached. No need to recheck.
+ if (!previous->nominal_length_flag) {
+ if (previous->entry_speed < current->entry_speed) {
+ double entry_speed = min( current->entry_speed,
+ max_allowable_speed(-previous->acceleration,previous->entry_speed,previous->millimeters) );
+
+ // Check for junction speed change
+ if (current->entry_speed != entry_speed) {
+ current->entry_speed = entry_speed;
+ current->recalculate_flag = true;
+ }
+ }
+ }
+}
+
+// planner_recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
+// implements the forward pass.
+void planner_forward_pass() {
+ uint8_t block_index = block_buffer_tail;
+ block_t *block[3] = { NULL, NULL, NULL };
+
+ while(block_index != block_buffer_head) {
+ block[0] = block[1];
+ block[1] = block[2];
+ block[2] = &block_buffer[block_index];
+ planner_forward_pass_kernel(block[0],block[1],block[2]);
+ block_index = next_block_index(block_index);
+ }
+ planner_forward_pass_kernel(block[1], block[2], NULL);
+}
+
+// Recalculates the trapezoid speed profiles for all blocks in the plan according to the
+// entry_factor for each junction. Must be called by planner_recalculate() after
+// updating the blocks.
+void planner_recalculate_trapezoids() {
+ int8_t block_index = block_buffer_tail;
+ block_t *current;
+ block_t *next = NULL;
+
+ while(block_index != block_buffer_head) {
+ current = next;
+ next = &block_buffer[block_index];
+ if (current) {
+ // Recalculate if current block entry or exit junction speed has changed.
+ if (current->recalculate_flag || next->recalculate_flag) {
+ // NOTE: Entry and exit factors always > 0 by all previous logic operations.
+ calculate_trapezoid_for_block(current, current->entry_speed/current->nominal_speed,
+ next->entry_speed/current->nominal_speed);
+ current->recalculate_flag = false; // Reset current only to ensure next trapezoid is computed
+ }
+ }
+ block_index = next_block_index( block_index );
+ }
+ // Last/newest block in buffer. Exit speed is set with MINIMUM_PLANNER_SPEED. Always recalculated.
+ if(next != NULL) {
+ calculate_trapezoid_for_block(next, next->entry_speed/next->nominal_speed,
+ MINIMUM_PLANNER_SPEED/next->nominal_speed);
+ next->recalculate_flag = false;
+ }
+}
+
+// Recalculates the motion plan according to the following algorithm:
+//
+// 1. Go over every block in reverse order and calculate a junction speed reduction (i.e. block_t.entry_factor)
+// so that:
+// a. The junction jerk is within the set limit
+// b. No speed reduction within one block requires faster deceleration than the one, true constant
+// acceleration.
+// 2. Go over every block in chronological order and dial down junction speed reduction values if
+// a. The speed increase within one block would require faster accelleration than the one, true
+// constant acceleration.
+//
+// When these stages are complete all blocks have an entry_factor that will allow all speed changes to
+// be performed using only the one, true constant acceleration, and where no junction jerk is jerkier than
+// the set limit. Finally it will:
+//
+// 3. Recalculate trapezoids for all blocks.
+
+void planner_recalculate() {
+ planner_reverse_pass();
+ planner_forward_pass();
+ planner_recalculate_trapezoids();
+}
+
+void plan_init() {
+ block_buffer_head = 0;
+ block_buffer_tail = 0;
+ memset(position, 0, sizeof(position)); // clear position
+ previous_speed[0] = 0.0;
+ previous_speed[1] = 0.0;
+ previous_speed[2] = 0.0;
+ previous_speed[3] = 0.0;
+ previous_nominal_speed = 0.0;
+}
+
+
+
+
+#ifdef AUTOTEMP
+void getHighESpeed()
+{
+ static float oldt=0;
+ if(!autotemp_enabled){
+ return;
+ }
+ if(degTargetHotend0()+2<autotemp_min) { //probably temperature set to zero.
+ return; //do nothing
+ }
+
+ float high=0.0;
+ uint8_t block_index = block_buffer_tail;
+
+ while(block_index != block_buffer_head) {
+ if((block_buffer[block_index].steps_x != 0) ||
+ (block_buffer[block_index].steps_y != 0) ||
+ (block_buffer[block_index].steps_z != 0)) {
+ float se=(float(block_buffer[block_index].steps_e)/float(block_buffer[block_index].step_event_count))*block_buffer[block_index].nominal_speed;
+ //se; mm/sec;
+ if(se>high)
+ {
+ high=se;
+ }
+ }
+ block_index = (block_index+1) & (BLOCK_BUFFER_SIZE - 1);
+ }
+
+ float g=autotemp_min+high*autotemp_factor;
+ float t=g;
+ if(t<autotemp_min)
+ t=autotemp_min;
+ if(t>autotemp_max)
+ t=autotemp_max;
+ if(oldt>t)
+ {
+ t=AUTOTEMP_OLDWEIGHT*oldt+(1-AUTOTEMP_OLDWEIGHT)*t;
+ }
+ oldt=t;
+ setTargetHotend0(t);
+}
+#endif
+
+void check_axes_activity() {
+ unsigned char x_active = 0;
+ unsigned char y_active = 0;
+ unsigned char z_active = 0;
+ unsigned char e_active = 0;
+ unsigned char fan_speed = 0;
+ unsigned char tail_fan_speed = 0;
+ block_t *block;
+
+ if(block_buffer_tail != block_buffer_head) {
+ uint8_t block_index = block_buffer_tail;
+ tail_fan_speed = block_buffer[block_index].fan_speed;
+ while(block_index != block_buffer_head) {
+ block = &block_buffer[block_index];
+ if(block->steps_x != 0) x_active++;
+ if(block->steps_y != 0) y_active++;
+ if(block->steps_z != 0) z_active++;
+ if(block->steps_e != 0) e_active++;
+ if(block->fan_speed != 0) fan_speed++;
+ block_index = (block_index+1) & (BLOCK_BUFFER_SIZE - 1);
+ }
+ }
+ else {
+ #if FAN_PIN > -1
+ if (FanSpeed != 0) analogWrite(FAN_PIN,FanSpeed); // If buffer is empty use current fan speed
+ #endif
+ }
+ if((DISABLE_X) && (x_active == 0)) disable_x();
+ if((DISABLE_Y) && (y_active == 0)) disable_y();
+ if((DISABLE_Z) && (z_active == 0)) disable_z();
+ if((DISABLE_E) && (e_active == 0)) { disable_e0();disable_e1();disable_e2(); }
+ #if FAN_PIN > -1
+ if((FanSpeed == 0) && (fan_speed ==0)) analogWrite(FAN_PIN, 0);
+ #endif
+ if (FanSpeed != 0 && tail_fan_speed !=0) {
+ analogWrite(FAN_PIN,tail_fan_speed);
+ }
+}
+
+
+float junction_deviation = 0.1;
+// Add a new linear movement to the buffer. steps_x, _y and _z is the absolute position in
+// mm. Microseconds specify how many microseconds the move should take to perform. To aid acceleration
+// calculation the caller must also provide the physical length of the line in millimeters.
+void plan_buffer_line(const float &x, const float &y, const float &z, const float &e, float feed_rate, const uint8_t &extruder)
+{
+ // Calculate the buffer head after we push this byte
+ int next_buffer_head = next_block_index(block_buffer_head);
+
+ // If the buffer is full: good! That means we are well ahead of the robot.
+ // Rest here until there is room in the buffer.
+ while(block_buffer_tail == next_buffer_head) {
+ manage_heater();
+ manage_inactivity(1);
+ LCD_STATUS;
+ LED_STATUS;
+ }
+
+ // The target position of the tool in absolute steps
+ // Calculate target position in absolute steps
+ //this should be done after the wait, because otherwise a M92 code within the gcode disrupts this calculation somehow
+ long target[4];
+ target[X_AXIS] = lround(x*axis_steps_per_unit[X_AXIS]);
+ target[Y_AXIS] = lround(y*axis_steps_per_unit[Y_AXIS]);
+ target[Z_AXIS] = lround(z*axis_steps_per_unit[Z_AXIS]);
+ target[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
+
+ #ifdef PREVENT_DANGEROUS_EXTRUDE
+ if(target[E_AXIS]!=position[E_AXIS])
+ if(degHotend(active_extruder)<EXTRUDE_MINTEMP && !allow_cold_extrude)
+ {
+ position[E_AXIS]=target[E_AXIS]; //behave as if the move really took place, but ignore E part
+ SERIAL_ECHO_START;
+ SERIAL_ECHOLNPGM(MSG_ERR_COLD_EXTRUDE_STOP);
+ }
+ if(labs(target[E_AXIS]-position[E_AXIS])>axis_steps_per_unit[E_AXIS]*EXTRUDE_MAXLENGTH)
+ {
+ position[E_AXIS]=target[E_AXIS]; //behave as if the move really took place, but ignore E part
+ SERIAL_ECHO_START;
+ SERIAL_ECHOLNPGM(MSG_ERR_LONG_EXTRUDE_STOP);
+ }
+ #endif
+
+ // Prepare to set up new block
+ block_t *block = &block_buffer[block_buffer_head];
+
+ // Mark block as not busy (Not executed by the stepper interrupt)
+ block->busy = false;
+
+ // Number of steps for each axis
+ block->steps_x = labs(target[X_AXIS]-position[X_AXIS]);
+ block->steps_y = labs(target[Y_AXIS]-position[Y_AXIS]);
+ block->steps_z = labs(target[Z_AXIS]-position[Z_AXIS]);
+ block->steps_e = labs(target[E_AXIS]-position[E_AXIS]);
+ block->steps_e *= extrudemultiply;
+ block->steps_e /= 100;
+ block->step_event_count = max(block->steps_x, max(block->steps_y, max(block->steps_z, block->steps_e)));
+
+ // Bail if this is a zero-length block
+ if (block->step_event_count <= dropsegments) { return; };
+
+ block->fan_speed = FanSpeed;
+
+ // Compute direction bits for this block
+ block->direction_bits = 0;
+ if (target[X_AXIS] < position[X_AXIS]) { block->direction_bits |= (1<<X_AXIS); }
+ if (target[Y_AXIS] < position[Y_AXIS]) { block->direction_bits |= (1<<Y_AXIS); }
+ 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();
+ #ifndef Z_LATE_ENABLE
+ if(block->steps_z != 0) enable_z();
+ #endif
+
+ // Enable all
+ // N571 disables real E drive! (ie. on laser operations)
+ if (!n571_enabled) {
+ if(block->steps_e != 0) { enable_e0();enable_e1();enable_e2(); }
+ }
+
+ if (block->steps_e == 0) {
+ if(feed_rate<mintravelfeedrate) feed_rate=mintravelfeedrate;
+ }
+ else {
+ if(feed_rate<minimumfeedrate) feed_rate=minimumfeedrate;
+ }
+
+ 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];
+ delta_mm[Z_AXIS] = (target[Z_AXIS]-position[Z_AXIS])/axis_steps_per_unit[Z_AXIS];
+ delta_mm[E_AXIS] = ((target[E_AXIS]-position[E_AXIS])/axis_steps_per_unit[E_AXIS])*extrudemultiply/100.0;
+// if ( block->steps_x <=dropsegments && block->steps_y <=dropsegments && block->steps_z <=dropsegments ) {
+// block->millimeters = abs(delta_mm[E_AXIS]);
+// } else {
+// block->millimeters = sqrt(square(delta_mm[X_AXIS]) + square(delta_mm[Y_AXIS]) + square(delta_mm[Z_AXIS]));
+// }
+
+// TODO - JMG - SORT OUT RETRACTS WHEN e IS NOT ALONE
+ block->millimeters = sqrt(square(delta_mm[X_AXIS]) + square(delta_mm[Y_AXIS]) +
+ square(delta_mm[Z_AXIS]) + square(delta_mm[E_AXIS]));
+ float inverse_millimeters = 1.0/block->millimeters; // Inverse millimeters to remove multiple divides
+
+ // Calculate speed in mm/second for each axis. No divide by zero due to previous checks.
+ float inverse_second = feed_rate * inverse_millimeters;
+
+ int moves_queued=(block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1);
+
+ // slow down when de buffer starts to empty, rather than wait at the corner for a buffer refill
+ #ifdef OLD_SLOWDOWN
+ if(moves_queued < (BLOCK_BUFFER_SIZE * 0.5) && moves_queued > 1) feed_rate = feed_rate*moves_queued / (BLOCK_BUFFER_SIZE * 0.5);
+ #endif
+
+ #ifdef SLOWDOWN
+ // segment time im micro seconds
+ unsigned long segment_time = lround(1000000.0/inverse_second);
+ if ((moves_queued > 1) && (moves_queued < (BLOCK_BUFFER_SIZE * 0.5))) {
+ if (segment_time < minsegmenttime) { // buffer is draining, add extra time. The amount of time added increases if the buffer is still emptied more.
+ inverse_second=1000000.0/(segment_time+lround(2*(minsegmenttime-segment_time)/moves_queued));
+ }
+ }
+ #endif
+ // END OF SLOW DOWN SECTION
+
+
+ block->nominal_speed = block->millimeters * inverse_second; // (mm/sec) Always > 0
+ block->nominal_rate = ceil(block->step_event_count * inverse_second); // (step/sec) Always > 0
+
+ // Calculate and limit speed in mm/sec for each axis
+ float current_speed[4];
+ float speed_factor = 1.0; //factor <=1 do decrease speed
+ for(int i=0; i < 4; i++) {
+ current_speed[i] = delta_mm[i] * inverse_second;
+ if(fabs(current_speed[i]) > max_feedrate[i])
+ speed_factor = min(speed_factor, max_feedrate[i] / fabs(current_speed[i]));
+ }
+
+// Max segement time in us.
+#ifdef XY_FREQUENCY_LIMIT
+#define MAX_FREQ_TIME (1000000.0/XY_FREQUENCY_LIMIT)
+
+ // Check and limit the xy direction change frequency
+ unsigned char direction_change = block->direction_bits ^ old_direction_bits;
+ old_direction_bits = block->direction_bits;
+
+ if((direction_change & (1<<X_AXIS)) == 0) {
+ x_segment_time[0] += segment_time;
+ }
+ else {
+ x_segment_time[2] = x_segment_time[1];
+ x_segment_time[1] = x_segment_time[0];
+ x_segment_time[0] = segment_time;
+ }
+ if((direction_change & (1<<Y_AXIS)) == 0) {
+ y_segment_time[0] += segment_time;
+ }
+ else {
+ y_segment_time[2] = y_segment_time[1];
+ y_segment_time[1] = y_segment_time[0];
+ y_segment_time[0] = segment_time;
+ }
+ long max_x_segment_time = max(x_segment_time[0], max(x_segment_time[1], x_segment_time[2]));
+ long max_y_segment_time = max(y_segment_time[0], max(y_segment_time[1], y_segment_time[2]));
+ long min_xy_segment_time =min(max_x_segment_time, max_y_segment_time);
+ if(min_xy_segment_time < MAX_FREQ_TIME) speed_factor = min(speed_factor, speed_factor * (float)min_xy_segment_time / (float)MAX_FREQ_TIME);
+#endif
+
+ // Correct the speed
+ if( speed_factor < 1.0) {
+ for(unsigned char i=0; i < 4; i++) {
+ current_speed[i] *= speed_factor;
+ }
+ block->nominal_speed *= speed_factor;
+ block->nominal_rate *= speed_factor;
+ }
+
+ // Compute and limit the acceleration rate for the trapezoid generator.
+ float steps_per_mm = block->step_event_count/block->millimeters;
+ if(block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0) {
+ block->acceleration_st = ceil(retract_acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
+ }
+ else {
+ block->acceleration_st = ceil(acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
+ // Limit acceleration per axis
+ if(((float)block->acceleration_st * (float)block->steps_x / (float)block->step_event_count) > axis_steps_per_sqr_second[X_AXIS])
+ block->acceleration_st = axis_steps_per_sqr_second[X_AXIS];
+ if(((float)block->acceleration_st * (float)block->steps_y / (float)block->step_event_count) > axis_steps_per_sqr_second[Y_AXIS])
+ block->acceleration_st = axis_steps_per_sqr_second[Y_AXIS];
+ if(((float)block->acceleration_st * (float)block->steps_e / (float)block->step_event_count) > axis_steps_per_sqr_second[E_AXIS])
+ block->acceleration_st = axis_steps_per_sqr_second[E_AXIS];
+ if(((float)block->acceleration_st * (float)block->steps_z / (float)block->step_event_count ) > axis_steps_per_sqr_second[Z_AXIS])
+ block->acceleration_st = axis_steps_per_sqr_second[Z_AXIS];
+ }
+ block->acceleration = block->acceleration_st / steps_per_mm;
+ block->acceleration_rate = (long)((float)block->acceleration_st * 8.388608);
+
+#if 0 // Use old jerk for now
+ // Compute path unit vector
+ double unit_vec[3];
+
+ unit_vec[X_AXIS] = delta_mm[X_AXIS]*inverse_millimeters;
+ unit_vec[Y_AXIS] = delta_mm[Y_AXIS]*inverse_millimeters;
+ unit_vec[Z_AXIS] = delta_mm[Z_AXIS]*inverse_millimeters;
+
+ // Compute maximum allowable entry speed at junction by centripetal acceleration approximation.
+ // Let a circle be tangent to both previous and current path line segments, where the junction
+ // deviation is defined as the distance from the junction to the closest edge of the circle,
+ // colinear with the circle center. The circular segment joining the two paths represents the
+ // path of centripetal acceleration. Solve for max velocity based on max acceleration about the
+ // radius of the circle, defined indirectly by junction deviation. This may be also viewed as
+ // path width or max_jerk in the previous grbl version. This approach does not actually deviate
+ // from path, but used as a robust way to compute cornering speeds, as it takes into account the
+ // nonlinearities of both the junction angle and junction velocity.
+ double vmax_junction = MINIMUM_PLANNER_SPEED; // Set default max junction speed
+
+ // Skip first block or when previous_nominal_speed is used as a flag for homing and offset cycles.
+ if ((block_buffer_head != block_buffer_tail) && (previous_nominal_speed > 0.0)) {
+ // Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
+ // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
+ double cos_theta = - previous_unit_vec[X_AXIS] * unit_vec[X_AXIS]
+ - previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS]
+ - previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ;
+
+ // Skip and use default max junction speed for 0 degree acute junction.
+ if (cos_theta < 0.95) {
+ vmax_junction = min(previous_nominal_speed,block->nominal_speed);
+ // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
+ if (cos_theta > -0.95) {
+ // Compute maximum junction velocity based on maximum acceleration and junction deviation
+ double sin_theta_d2 = sqrt(0.5*(1.0-cos_theta)); // Trig half angle identity. Always positive.
+ vmax_junction = min(vmax_junction,
+ sqrt(block->acceleration * junction_deviation * sin_theta_d2/(1.0-sin_theta_d2)) );
+ }
+ }
+ }
+#endif
+ // Start with a safe speed
+ float vmax_junction = max_xy_jerk/2;
+ if(fabs(current_speed[Z_AXIS]) > max_z_jerk/2)
+ vmax_junction = max_z_jerk/2;
+ vmax_junction = min(vmax_junction, block->nominal_speed);
+ if(fabs(current_speed[E_AXIS]) > max_e_jerk/2)
+ vmax_junction = min(vmax_junction, max_e_jerk/2);
+
+ if ((moves_queued > 1) && (previous_nominal_speed > 0.0001)) {
+ float jerk = sqrt(pow((current_speed[X_AXIS]-previous_speed[X_AXIS]), 2)+pow((current_speed[Y_AXIS]-previous_speed[Y_AXIS]), 2));
+ if((fabs(previous_speed[X_AXIS]) > 0.0001) || (fabs(previous_speed[Y_AXIS]) > 0.0001)) {
+ vmax_junction = block->nominal_speed;
+ }
+ if (jerk > max_xy_jerk) {
+ vmax_junction *= (max_xy_jerk/jerk);
+ }
+ if(fabs(current_speed[Z_AXIS] - previous_speed[Z_AXIS]) > max_z_jerk) {
+ vmax_junction *= (max_z_jerk/fabs(current_speed[Z_AXIS] - previous_speed[Z_AXIS]));
+ }
+ if(fabs(current_speed[E_AXIS] - previous_speed[E_AXIS]) > max_e_jerk) {
+ vmax_junction *= (max_e_jerk/fabs(current_speed[E_AXIS] - previous_speed[E_AXIS]));
+ }
+ }
+ block->max_entry_speed = vmax_junction;
+
+ // Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
+ double v_allowable = max_allowable_speed(-block->acceleration,MINIMUM_PLANNER_SPEED,block->millimeters);
+ block->entry_speed = min(vmax_junction, v_allowable);
+
+ // Initialize planner efficiency flags
+ // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds.
+ // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then
+ // the current block and next block junction speeds are guaranteed to always be at their maximum
+ // junction speeds in deceleration and acceleration, respectively. This is due to how the current
+ // block nominal speed limits both the current and next maximum junction speeds. Hence, in both
+ // the reverse and forward planners, the corresponding block junction speed will always be at the
+ // the maximum junction speed and may always be ignored for any speed reduction checks.
+ if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; }
+ else { block->nominal_length_flag = false; }
+ block->recalculate_flag = true; // Always calculate trapezoid for new block
+
+ // Update previous path unit_vector and nominal speed
+ memcpy(previous_speed, current_speed, sizeof(previous_speed)); // previous_speed[] = current_speed[]
+ previous_nominal_speed = block->nominal_speed;
+
+
+ #ifdef ADVANCE
+ // Calculate advance rate
+ if((block->steps_e == 0) || (block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0)) {
+ block->advance_rate = 0;
+ block->advance = 0;
+ }
+ else {
+ long acc_dist = estimate_acceleration_distance(0, block->nominal_rate, block->acceleration_st);
+ float advance = (STEPS_PER_CUBIC_MM_E * advance_k) *
+ (current_speed[E_AXIS] * current_speed[E_AXIS] * EXTRUTION_AREA * EXTRUTION_AREA)*256;
+ block->advance = advance;
+ if(acc_dist == 0) {
+ block->advance_rate = 0;
+ }
+ else {
+ block->advance_rate = advance / (float)acc_dist;
+ }
+ }
+ /*
+ SERIAL_ECHO_START;
+ SERIAL_ECHOPGM("advance :");
+ SERIAL_ECHO(block->advance/256.0);
+ SERIAL_ECHOPGM("advance rate :");
+ SERIAL_ECHOLN(block->advance_rate/256.0);
+ */
+ #endif // ADVANCE
+
+ calculate_trapezoid_for_block(block, block->entry_speed/block->nominal_speed,
+ MINIMUM_PLANNER_SPEED/block->nominal_speed);
+
+ // Move buffer head
+ block_buffer_head = next_buffer_head;
+
+ // Update position
+ memcpy(position, target, sizeof(target)); // position[] = target[]
+
+ planner_recalculate();
+
+ st_wake_up();
+}
+
+void plan_set_position(const float &x, const float &y, const float &z, const float &e)
+{
+ position[X_AXIS] = lround(x*axis_steps_per_unit[X_AXIS]);
+ position[Y_AXIS] = lround(y*axis_steps_per_unit[Y_AXIS]);
+ position[Z_AXIS] = lround(z*axis_steps_per_unit[Z_AXIS]);
+ position[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
+ st_set_position(position[X_AXIS], position[Y_AXIS], position[Z_AXIS], position[E_AXIS]);
+ previous_nominal_speed = 0.0; // Resets planner junction speeds. Assumes start from rest.
+ previous_speed[0] = 0.0;
+ previous_speed[1] = 0.0;
+ previous_speed[2] = 0.0;
+ previous_speed[3] = 0.0;
+}
+
+void plan_set_e_position(const float &e)
+{
+ position[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
+ st_set_e_position(position[E_AXIS]);
+}
+
+uint8_t movesplanned()
+{
+ return (block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1);
+}
+
+void allow_cold_extrudes(bool allow)
+{
+ #ifdef PREVENT_DANGEROUS_EXTRUDE
+ allow_cold_extrude=allow;
+ #endif
+}