src/modules/tools/extruder/Extruder.cpp

   1 /*
   2     This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
   3     Smoothie 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.
   4     Smoothie 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.
   5     You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6 */
   7
   8 #include "Extruder.h"
   9
  10 #include "libs/Module.h"
  11 #include "libs/Kernel.h"
  12
  13 #include "modules/robot/Conveyor.h"
  14 #include "modules/robot/Block.h"
  15 #include "StepperMotor.h"
  16 #include "SlowTicker.h"
  17 #include "Stepper.h"
  18 #include "StepTicker.h"
  19 #include "Config.h"
  20 #include "StepperMotor.h"
  21 #include "Robot.h"
  22 #include "checksumm.h"
  23 #include "ConfigValue.h"
  24 #include "Gcode.h"
  25 #include "libs/StreamOutput.h"
  26 #include "PublicDataRequest.h"
  27
  28 #include <mri.h>
  29
  30 // OLD config names for backwards compatibility, NOTE new configs will not be added here
  31 #define extruder_module_enable_checksum      CHECKSUM("extruder_module_enable")
  32 #define extruder_steps_per_mm_checksum       CHECKSUM("extruder_steps_per_mm")
  33 #define extruder_filament_diameter_checksum  CHECKSUM("extruder_filament_diameter")
  34 #define extruder_acceleration_checksum       CHECKSUM("extruder_acceleration")
  35 #define extruder_step_pin_checksum           CHECKSUM("extruder_step_pin")
  36 #define extruder_dir_pin_checksum            CHECKSUM("extruder_dir_pin")
  37 #define extruder_en_pin_checksum             CHECKSUM("extruder_en_pin")
  38 #define extruder_max_speed_checksum          CHECKSUM("extruder_max_speed")
  39
  40 // NEW config names
  41 #define extruder_checksum                    CHECKSUM("extruder")
  42
  43 #define default_feed_rate_checksum           CHECKSUM("default_feed_rate")
  44 #define steps_per_mm_checksum                CHECKSUM("steps_per_mm")
  45 #define filament_diameter_checksum           CHECKSUM("filament_diameter")
  46 #define acceleration_checksum                CHECKSUM("acceleration")
  47 #define step_pin_checksum                    CHECKSUM("step_pin")
  48 #define dir_pin_checksum                     CHECKSUM("dir_pin")
  49 #define en_pin_checksum                      CHECKSUM("en_pin")
  50 #define max_speed_checksum                   CHECKSUM("max_speed")
  51 #define x_offset_checksum                    CHECKSUM("x_offset")
  52 #define y_offset_checksum                    CHECKSUM("y_offset")
  53 #define z_offset_checksum                    CHECKSUM("z_offset")
  54
  55 #define retract_length_checksum              CHECKSUM("retract_length")
  56 #define retract_feedrate_checksum            CHECKSUM("retract_feedrate")
  57 #define retract_recover_length_checksum      CHECKSUM("retract_recover_length")
  58 #define retract_recover_feedrate_checksum    CHECKSUM("retract_recover_feedrate")
  59 #define retract_zlift_length_checksum        CHECKSUM("retract_zlift_length")
  60 #define retract_zlift_feedrate_checksum      CHECKSUM("retract_zlift_feedrate")
  61
  62 #define X_AXIS      0
  63 #define Y_AXIS      1
  64 #define Z_AXIS      2
  65
  66 #define OFF 0
  67 #define SOLO 1
  68 #define FOLLOW 2
  69
  70 #define PI 3.14159265358979F
  71
  72 #define max(a,b) (((a) > (b)) ? (a) : (b))
  73
  74 /* The extruder module controls a filament extruder for 3D printing: http://en.wikipedia.org/wiki/Fused_deposition_modeling
  75 * It can work in two modes : either the head does not move, and the extruder moves the filament at a specified speed ( SOLO mode here )
  76 * or the head moves, and the extruder moves plastic at a speed proportional to the movement of the head ( FOLLOW mode here ).
  77 */
  78
  79 Extruder::Extruder( uint16_t config_identifier, bool single )
  80 {
  81     this->absolute_mode = true;
  82     this->enabled = false;
  83     this->paused = false;
  84     this->single_config = single;
  85     this->identifier = config_identifier;
  86     this->retracted = false;
  87     this->volumetric_multiplier = 1.0F;
  88     this->extruder_multiplier = 1.0F;
  89     this->stepper_motor= nullptr;
  90
  91     memset(this->offset, 0, sizeof(this->offset));
  92 }
  93
  94 Extruder::~Extruder()
  95 {
  96     delete stepper_motor;
  97 }
  98
  99 void Extruder::on_halt(void *arg)
 100 {
 101     if(arg == nullptr) {
 102         // turn off motor
 103         this->en_pin.set(1);
 104         // disable if multi extruder
 105         if(!this->single_config)
 106             this->enabled= false;
 107     }
 108 }
 109
 110 void Extruder::on_module_loaded()
 111 {
 112     // Settings
 113     this->on_config_reload(this);
 114
 115     // Start values
 116     this->target_position = 0;
 117     this->current_position = 0;
 118     this->unstepped_distance = 0;
 119     this->current_block = NULL;
 120     this->mode = OFF;
 121
 122     // We work on the same Block as Stepper, so we need to know when it gets a new one and drops one
 123     this->register_for_event(ON_BLOCK_BEGIN);
 124     this->register_for_event(ON_BLOCK_END);
 125     this->register_for_event(ON_GCODE_RECEIVED);
 126     this->register_for_event(ON_GCODE_EXECUTE);
 127     this->register_for_event(ON_PLAY);
 128     this->register_for_event(ON_PAUSE);
 129     this->register_for_event(ON_HALT);
 130     this->register_for_event(ON_SPEED_CHANGE);
 131     this->register_for_event(ON_GET_PUBLIC_DATA);
 132
 133     // Update speed every *acceleration_ticks_per_second*
 134     THEKERNEL->slow_ticker->attach( THEKERNEL->stepper->get_acceleration_ticks_per_second() , this, &Extruder::acceleration_tick );
 135 }
 136
 137 // Get config
 138 void Extruder::on_config_reload(void *argument)
 139 {
 140     if( this->single_config ) {
 141         // If this module uses the old "single extruder" configuration style
 142
 143         this->steps_per_millimeter        = THEKERNEL->config->value(extruder_steps_per_mm_checksum      )->by_default(1)->as_number();
 144         this->filament_diameter           = THEKERNEL->config->value(extruder_filament_diameter_checksum )->by_default(0)->as_number();
 145         this->acceleration                = THEKERNEL->config->value(extruder_acceleration_checksum      )->by_default(1000)->as_number();
 146         this->feed_rate                   = THEKERNEL->config->value(default_feed_rate_checksum          )->by_default(1000)->as_number();
 147
 148         this->step_pin.from_string(         THEKERNEL->config->value(extruder_step_pin_checksum          )->by_default("nc" )->as_string())->as_output();
 149         this->dir_pin.from_string(          THEKERNEL->config->value(extruder_dir_pin_checksum           )->by_default("nc" )->as_string())->as_output();
 150         this->en_pin.from_string(           THEKERNEL->config->value(extruder_en_pin_checksum            )->by_default("nc" )->as_string())->as_output();
 151
 152         for(int i = 0; i < 3; i++) {
 153             this->offset[i] = 0;
 154         }
 155
 156         this->enabled = true;
 157
 158     } else {
 159         // If this module was created with the new multi extruder configuration style
 160
 161         this->steps_per_millimeter = THEKERNEL->config->value(extruder_checksum, this->identifier, steps_per_mm_checksum      )->by_default(1)->as_number();
 162         this->filament_diameter    = THEKERNEL->config->value(extruder_checksum, this->identifier, filament_diameter_checksum )->by_default(0)->as_number();
 163         this->acceleration         = THEKERNEL->config->value(extruder_checksum, this->identifier, acceleration_checksum      )->by_default(1000)->as_number();
 164         this->feed_rate            = THEKERNEL->config->value(                                     default_feed_rate_checksum )->by_default(1000)->as_number();
 165
 166         this->step_pin.from_string( THEKERNEL->config->value(extruder_checksum, this->identifier, step_pin_checksum          )->by_default("nc" )->as_string())->as_output();
 167         this->dir_pin.from_string(  THEKERNEL->config->value(extruder_checksum, this->identifier, dir_pin_checksum           )->by_default("nc" )->as_string())->as_output();
 168         this->en_pin.from_string(   THEKERNEL->config->value(extruder_checksum, this->identifier, en_pin_checksum            )->by_default("nc" )->as_string())->as_output();
 169
 170         this->offset[X_AXIS] = THEKERNEL->config->value(extruder_checksum, this->identifier, x_offset_checksum          )->by_default(0)->as_number();
 171         this->offset[Y_AXIS] = THEKERNEL->config->value(extruder_checksum, this->identifier, y_offset_checksum          )->by_default(0)->as_number();
 172         this->offset[Z_AXIS] = THEKERNEL->config->value(extruder_checksum, this->identifier, z_offset_checksum          )->by_default(0)->as_number();
 173
 174     }
 175
 176     // these are only supported in the new syntax, no need to be backward compatible as they did not exist before the change
 177     this->retract_length           = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_length_checksum)->by_default(3)->as_number();
 178     this->retract_feedrate         = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_feedrate_checksum)->by_default(45)->as_number();
 179     this->retract_recover_length   = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_recover_length_checksum)->by_default(0)->as_number();
 180     this->retract_recover_feedrate = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_recover_feedrate_checksum)->by_default(8)->as_number();
 181     this->retract_zlift_length     = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_zlift_length_checksum)->by_default(0)->as_number();
 182     this->retract_zlift_feedrate   = THEKERNEL->config->value(extruder_checksum, this->identifier, retract_zlift_feedrate_checksum)->by_default(100*60)->as_number(); // mm/min
 183
 184     if(filament_diameter > 0.01) {
 185         this->volumetric_multiplier = 1.0F / (powf(this->filament_diameter / 2, 2) * PI);
 186     }
 187
 188     // Stepper motor object for the extruder
 189     this->stepper_motor = new StepperMotor(step_pin, dir_pin, en_pin);
 190     this->stepper_motor->attach(this, &Extruder::stepper_motor_finished_move );
 191     if( this->single_config ) {
 192         this->stepper_motor->set_max_rate(THEKERNEL->config->value(extruder_max_speed_checksum)->by_default(1000)->as_number());
 193     }else{
 194         this->stepper_motor->set_max_rate(THEKERNEL->config->value(extruder_checksum, this->identifier, max_speed_checksum)->by_default(1000)->as_number());
 195     }
 196 }
 197
 198 void Extruder::on_get_public_data(void* argument){
 199     PublicDataRequest* pdr = static_cast<PublicDataRequest*>(argument);
 200
 201     if(!pdr->starts_with(extruder_checksum)) return;
 202
 203     if(this->enabled) {
 204         // Note this is allowing both step/mm and filament diameter to be exposed via public data
 205         pdr->set_data_ptr(&this->steps_per_millimeter);
 206         pdr->set_taken();
 207     }
 208 }
 209
 210 // When the play/pause button is set to pause, or a module calls the ON_PAUSE event
 211 void Extruder::on_pause(void *argument)
 212 {
 213     this->paused = true;
 214     this->stepper_motor->pause();
 215 }
 216
 217 // When the play/pause button is set to play, or a module calls the ON_PLAY event
 218 void Extruder::on_play(void *argument)
 219 {
 220     this->paused = false;
 221     this->stepper_motor->unpause();
 222 }
 223
 224 void Extruder::on_gcode_received(void *argument)
 225 {
 226     Gcode *gcode = static_cast<Gcode *>(argument);
 227
 228     // M codes most execute immediately, most only execute if enabled
 229     if (gcode->has_m) {
 230         if (gcode->m == 114 && this->enabled) {
 231             char buf[16];
 232             int n = snprintf(buf, sizeof(buf), " E:%1.3f ", this->current_position);
 233             gcode->txt_after_ok.append(buf, n);
 234             gcode->mark_as_taken();
 235
 236         } else if (gcode->m == 92 && ( (this->enabled && !gcode->has_letter('P')) || (gcode->has_letter('P') && gcode->get_value('P') == this->identifier) ) ) {
 237             float spm = this->steps_per_millimeter;
 238             if (gcode->has_letter('E')) {
 239                 spm = gcode->get_value('E');
 240                 this->steps_per_millimeter = spm;
 241             }
 242
 243             gcode->stream->printf("E:%g ", spm);
 244             gcode->add_nl = true;
 245             gcode->mark_as_taken();
 246
 247         } else if (gcode->m == 200 && ( (this->enabled && !gcode->has_letter('P')) || (gcode->has_letter('P') && gcode->get_value('P') == this->identifier)) ) {
 248             if (gcode->has_letter('D')) {
 249                 THEKERNEL->conveyor->wait_for_empty_queue(); // only apply after the queue has emptied
 250                 this->filament_diameter = gcode->get_value('D');
 251                 if(filament_diameter > 0.01) {
 252                     this->volumetric_multiplier = 1.0F / (powf(this->filament_diameter / 2, 2) * PI);
 253                 }else{
 254                     this->volumetric_multiplier = 1.0F;
 255                 }
 256             }
 257             gcode->mark_as_taken();
 258
 259         } else if (gcode->m == 204 && gcode->has_letter('E') &&
 260                    ( (this->enabled && !gcode->has_letter('P')) || (gcode->has_letter('P') && gcode->get_value('P') == this->identifier)) ) {
 261             // extruder acceleration M204 Ennn mm/sec^2 (Pnnn sets the specific extruder for M500)
 262             this->acceleration= gcode->get_value('E');
 263             gcode->mark_as_taken();
 264
 265         } else if (gcode->m == 207 && ( (this->enabled && !gcode->has_letter('P')) || (gcode->has_letter('P') && gcode->get_value('P') == this->identifier)) ) {
 266             // M207 - set retract length S[positive mm] F[feedrate mm/min] Z[additional zlift/hop] Q[zlift feedrate mm/min]
 267             if(gcode->has_letter('S')) retract_length = gcode->get_value('S');
 268             if(gcode->has_letter('F')) retract_feedrate = gcode->get_value('F')/60.0F; // specified in mm/min converted to mm/sec
 269             if(gcode->has_letter('Z')) retract_zlift_length = gcode->get_value('Z');
 270             if(gcode->has_letter('Q')) retract_zlift_feedrate = gcode->get_value('Q');
 271             gcode->mark_as_taken();
 272
 273         } else if (gcode->m == 208 && ( (this->enabled && !gcode->has_letter('P')) || (gcode->has_letter('P') && gcode->get_value('P') == this->identifier)) ) {
 274             // M208 - set retract recover length S[positive mm surplus to the M207 S*] F[feedrate mm/min]
 275             if(gcode->has_letter('S')) retract_recover_length = gcode->get_value('S');
 276             if(gcode->has_letter('F')) retract_recover_feedrate = gcode->get_value('F')/60.0F; // specified in mm/min converted to mm/sec
 277             gcode->mark_as_taken();
 278
 279         } else if (gcode->m == 221 && this->enabled) { // M221 S100 change flow rate by percentage
 280             if(gcode->has_letter('S')) this->extruder_multiplier= gcode->get_value('S')/100.0F;
 281             gcode->mark_as_taken();
 282
 283         } else if (gcode->m == 500 || gcode->m == 503) { // M500 saves some volatile settings to config override file, M503 just prints the settings
 284             if( this->single_config ) {
 285                 gcode->stream->printf(";E Steps per mm:\nM92 E%1.4f\n", this->steps_per_millimeter);
 286                 gcode->stream->printf(";E Filament diameter:\nM200 D%1.4f\n", this->filament_diameter);
 287                 gcode->stream->printf(";E retract length, feedrate, zlift length, feedrate:\nM207 S%1.4f F%1.4f Z%1.4f Q%1.4f\n", this->retract_length, this->retract_feedrate*60.0F, this->retract_zlift_length, this->retract_zlift_feedrate);
 288                 gcode->stream->printf(";E retract recover length, feedrate:\nM208 S%1.4f F%1.4f\n", this->retract_recover_length, this->retract_recover_feedrate*60.0F);
 289                 gcode->stream->printf(";E acceleration mm/sec^2:\nM204 E%1.4f\n", this->acceleration);
 290
 291             } else {
 292                 gcode->stream->printf(";E Steps per mm:\nM92 E%1.4f P%d\n", this->steps_per_millimeter, this->identifier);
 293                 gcode->stream->printf(";E Filament diameter:\nM200 D%1.4f P%d\n", this->filament_diameter, this->identifier);
 294                 gcode->stream->printf(";E retract length, feedrate:\nM207 S%1.4f F%1.4f Z%1.4f Q%1.4f P%d\n", this->retract_length, this->retract_feedrate*60.0F, this->retract_zlift_length, this->retract_zlift_feedrate, this->identifier);
 295                 gcode->stream->printf(";E retract recover length, feedrate:\nM208 S%1.4f F%1.4f P%d\n", this->retract_recover_length, this->retract_recover_feedrate*60.0F, this->identifier);
 296                 gcode->stream->printf(";E acceleration mm/sec^2:\nM204 E%1.4f P%d\n", this->acceleration, this->identifier);
 297             }
 298             gcode->mark_as_taken();
 299         } else if( gcode->m == 17 || gcode->m == 18 || gcode->m == 82 || gcode->m == 83 || gcode->m == 84 ) {
 300             // Mcodes to pass along to on_gcode_execute
 301             THEKERNEL->conveyor->append_gcode(gcode);
 302             gcode->mark_as_taken();
 303         }
 304
 305     }else if(gcode->has_g) {
 306         // G codes, NOTE some are ignored if not enabled
 307         if( (gcode->g == 92 && gcode->has_letter('E')) || (gcode->g == 90 || gcode->g == 91) ) {
 308             // Gcodes to pass along to on_gcode_execute
 309             THEKERNEL->conveyor->append_gcode(gcode);
 310             gcode->mark_as_taken();
 311
 312         }else if( this->enabled && gcode->g < 4 && gcode->has_letter('E') && !gcode->has_letter('X') && !gcode->has_letter('Y') && !gcode->has_letter('Z') ) {
 313             // This is a solo move, we add an empty block to the queue to prevent subsequent gcodes being executed at the same time
 314             THEKERNEL->conveyor->append_gcode(gcode);
 315             THEKERNEL->conveyor->queue_head_block();
 316             gcode->mark_as_taken();
 317
 318         }else if( this->enabled && (gcode->g == 10 || gcode->g == 11) ) { // firmware retract command
 319             gcode->mark_as_taken();
 320             // check we are in the correct state of retract or unretract
 321             if(gcode->g == 10 && !retracted) {
 322                 this->retracted= true;
 323                 this->cancel_zlift_restore= false;
 324             } else if(gcode->g == 11 && retracted){
 325                 this->retracted= false;
 326             } else
 327                 return; // ignore duplicates
 328
 329             // now we do a special hack to add zlift if needed, this should go in Robot but if it did the zlift would be executed before retract which is bad
 330             // this way zlift will happen after retract, (or before for unretract) NOTE we call the robot->on_gcode_receive directly to avoid recursion
 331             if(retract_zlift_length > 0 && gcode->g == 11 && !this->cancel_zlift_restore) {
 332                 // reverse zlift happens before unretract
 333                 // NOTE we do not do this if cancel_zlift_restore is set to true, which happens if there is an absolute Z move inbetween G10 and G11
 334                 char buf[32];
 335                 int n= snprintf(buf, sizeof(buf), "G0 Z%1.4f F%1.4f", -retract_zlift_length, retract_zlift_feedrate);
 336                 string cmd(buf, n);
 337                 Gcode gc(cmd, &(StreamOutput::NullStream));
 338                 bool oldmode= THEKERNEL->robot->absolute_mode;
 339                 THEKERNEL->robot->absolute_mode= false; // needs to be relative mode
 340                 THEKERNEL->robot->on_gcode_received(&gc); // send to robot directly
 341                 THEKERNEL->robot->absolute_mode= oldmode; // restore mode
 342             }
 343
 344             // This is a solo move, we add an empty block to the queue to prevent subsequent gcodes being executed at the same time
 345             THEKERNEL->conveyor->append_gcode(gcode);
 346             THEKERNEL->conveyor->queue_head_block();
 347
 348             if(retract_zlift_length > 0 && gcode->g == 10) {
 349                 char buf[32];
 350                 int n= snprintf(buf, sizeof(buf), "G0 Z%1.4f F%1.4f", retract_zlift_length, retract_zlift_feedrate);
 351                 string cmd(buf, n);
 352                 Gcode gc(cmd, &(StreamOutput::NullStream));
 353                 bool oldmode= THEKERNEL->robot->absolute_mode;
 354                 THEKERNEL->robot->absolute_mode= false; // needs to be relative mode
 355                 THEKERNEL->robot->on_gcode_received(&gc); // send to robot directly
 356                 THEKERNEL->robot->absolute_mode= oldmode; // restore mode
 357             }
 358
 359         }else if( this->enabled && this->retracted && (gcode->g == 0 || gcode->g == 1) && gcode->has_letter('Z')) {
 360             // NOTE we cancel the zlift restore for the following G11 as we have moved to an absolute Z which we need to stay at
 361             this->cancel_zlift_restore= true;
 362         }
 363     }
 364 }
 365
 366 // Compute extrusion speed based on parameters and gcode distance of travel
 367 void Extruder::on_gcode_execute(void *argument)
 368 {
 369     Gcode *gcode = static_cast<Gcode *>(argument);
 370
 371     // The mode is OFF by default, and SOLO or FOLLOW only if we need to extrude
 372     this->mode = OFF;
 373
 374     // Absolute/relative mode, globably modal affect all extruders whether enabled or not
 375     if( gcode->has_m ) {
 376         switch(gcode->m) {
 377         case 17:
 378             this->en_pin.set(0);
 379             break;
 380         case 18:
 381             this->en_pin.set(1);
 382             break;
 383         case 82:
 384             this->absolute_mode = true;
 385             break;
 386         case 83:
 387             this->absolute_mode = false;
 388             break;
 389         case 84:
 390             this->en_pin.set(1);
 391             break;
 392         }
 393         return;
 394
 395     } else if( gcode->has_g && (gcode->g == 90 || gcode->g == 91) ) {
 396         this->absolute_mode = (gcode->g == 90);
 397         return;
 398     }
 399
 400
 401     if( gcode->has_g && this->enabled ) {
 402         // G92: Reset extruder position
 403         if( gcode->g == 92 ) {
 404             if( gcode->has_letter('E') ) {
 405                 this->current_position = gcode->get_value('E');
 406                 this->target_position  = this->current_position;
 407                 this->unstepped_distance = 0;
 408             } else if( gcode->get_num_args() == 0) {
 409                 this->current_position = 0.0;
 410                 this->target_position = this->current_position;
 411                 this->unstepped_distance = 0;
 412             }
 413
 414         } else if (gcode->g == 10) {
 415             // FW retract command
 416             feed_rate= retract_feedrate; // mm/sec
 417             this->mode = SOLO;
 418             this->travel_distance = -retract_length;
 419             this->target_position += this->travel_distance;
 420             this->en_pin.set(0);
 421
 422         } else if (gcode->g == 11) {
 423             // un retract command
 424             feed_rate= retract_recover_feedrate; // mm/sec
 425             this->mode = SOLO;
 426             this->travel_distance = (retract_length + retract_recover_length);
 427             this->target_position += this->travel_distance;
 428             this->en_pin.set(0);
 429
 430         } else if (gcode->g == 0 || gcode->g == 1) {
 431             // Extrusion length from 'G' Gcode
 432             if( gcode->has_letter('E' )) {
 433                 // Get relative extrusion distance depending on mode ( in absolute mode we must substract target_position )
 434                 float extrusion_distance = gcode->get_value('E');
 435                 float relative_extrusion_distance = extrusion_distance;
 436                 if (this->absolute_mode) {
 437                     relative_extrusion_distance -= this->target_position;
 438                     this->target_position = extrusion_distance;
 439                 } else {
 440                     this->target_position += relative_extrusion_distance;
 441                 }
 442
 443                 // If the robot is moving, we follow it's movement, otherwise, we move alone
 444                 if( fabs(gcode->millimeters_of_travel) < 0.0001F ) { // With floating numbers, we can have 0 != 0 ... beeeh. For more info see : http://upload.wikimedia.org/wikipedia/commons/0/0a/Cain_Henri_Vidal_Tuileries.jpg
 445                     this->mode = SOLO;
 446                     this->travel_distance = relative_extrusion_distance;
 447                 } else {
 448                     // We move proportionally to the robot's movement
 449                     this->mode = FOLLOW;
 450                     this->travel_ratio = (relative_extrusion_distance * this->volumetric_multiplier * this->extruder_multiplier) / gcode->millimeters_of_travel; // adjust for volumetric extrusion and extruder multiplier
 451                     // TODO: check resulting flowrate, limit robot speed if it exceeds max_speed
 452                 }
 453
 454                 this->en_pin.set(0);
 455             }
 456
 457             if (gcode->has_letter('F')) {
 458                 feed_rate = gcode->get_value('F') / THEKERNEL->robot->get_seconds_per_minute();
 459                 if (feed_rate > stepper_motor->get_max_rate())
 460                     feed_rate = stepper_motor->get_max_rate();
 461             }
 462         }
 463     }
 464 }
 465
 466 // When a new block begins, either follow the robot, or step by ourselves ( or stay back and do nothing )
 467 void Extruder::on_block_begin(void *argument)
 468 {
 469     if(!this->enabled) return;
 470     Block *block = static_cast<Block *>(argument);
 471
 472
 473     if( this->mode == SOLO ) {
 474         // In solo mode we take the block so we can move even if the stepper has nothing to do
 475
 476         this->current_position += this->travel_distance ;
 477
 478         int steps_to_step = abs(int(floor(this->steps_per_millimeter * (this->travel_distance + this->unstepped_distance) )));
 479
 480         if ( this->travel_distance > 0 ) {
 481             this->unstepped_distance += this->travel_distance - (steps_to_step / this->steps_per_millimeter); //catch any overflow
 482         }   else {
 483             this->unstepped_distance += this->travel_distance + (steps_to_step / this->steps_per_millimeter); //catch any overflow
 484         }
 485
 486         if( steps_to_step != 0 ) {
 487
 488             // We take the block, we have to release it or everything gets stuck
 489             block->take();
 490             this->current_block = block;
 491
 492             this->stepper_motor->move( ( this->travel_distance > 0 ), steps_to_step, 0);
 493
 494         } else {
 495             this->current_block = NULL;
 496         }
 497
 498     } else if( this->mode == FOLLOW ) {
 499         // In non-solo mode, we just follow the stepper module
 500         this->travel_distance = block->millimeters * this->travel_ratio;
 501
 502         this->current_position += this->travel_distance;
 503
 504         int steps_to_step = abs(int(floor(this->steps_per_millimeter * (this->travel_distance + this->unstepped_distance) )));
 505
 506         if ( this->travel_distance > 0 ) {
 507             this->unstepped_distance += this->travel_distance - (steps_to_step / this->steps_per_millimeter); //catch any overflow
 508         }   else {
 509             this->unstepped_distance += this->travel_distance + (steps_to_step / this->steps_per_millimeter); //catch any overflow
 510         }
 511
 512         if( steps_to_step != 0 ) {
 513             block->take();
 514             this->current_block = block;
 515
 516             this->stepper_motor->move( ( this->travel_distance > 0 ), steps_to_step);
 517             on_speed_change(this); // set initial speed
 518         } else {
 519             this->current_block = NULL;
 520         }
 521
 522     } else if( this->mode == OFF ) {
 523         // No movement means we must reset our speed
 524         this->current_block = NULL;
 525         //this->stepper_motor->set_speed(0);
 526
 527     }
 528
 529 }
 530
 531 // When a block ends, pause the stepping interrupt
 532 void Extruder::on_block_end(void *argument)
 533 {
 534     if(!this->enabled) return;
 535     this->current_block = NULL;
 536 }
 537
 538 // Called periodically to change the speed to match acceleration or to match the speed of the robot
 539 // Only used in SOLO mode
 540 uint32_t Extruder::acceleration_tick(uint32_t dummy)
 541 {
 542     if(!this->enabled) return 0;
 543
 544     // Avoid trying to work when we really shouldn't ( between blocks or re-entry )
 545     if( this->current_block == NULL ||  this->paused || this->mode != SOLO ) {
 546         return 0;
 547     }
 548
 549     if(!this->stepper_motor->is_moving()) return 0;
 550
 551     uint32_t current_rate = this->stepper_motor->get_steps_per_second();
 552     uint32_t target_rate = int(floor(this->feed_rate * this->steps_per_millimeter));
 553
 554     if( current_rate < target_rate ) {
 555         uint32_t rate_increase = int(floor((this->acceleration / THEKERNEL->stepper->get_acceleration_ticks_per_second()) * this->steps_per_millimeter));
 556         current_rate = min( target_rate, current_rate + rate_increase );
 557     }
 558     if( current_rate > target_rate ) {
 559         current_rate = target_rate;
 560     }
 561
 562     // steps per second
 563     this->stepper_motor->set_speed(current_rate);
 564
 565     return 0;
 566 }
 567
 568 // Speed has been updated for the robot's stepper, we must update accordingly
 569 void Extruder::on_speed_change( void *argument )
 570 {
 571     if(!this->enabled) return;
 572
 573     // Avoid trying to work when we really shouldn't ( between blocks or re-entry )
 574     if( this->current_block == NULL ||  this->paused || this->mode != FOLLOW || !this->stepper_motor->is_moving()) {
 575         return;
 576     }
 577
 578     // if we are flushing the queue we need to stop the motor when it has decelerated to zero, we get this call with argumnet == 0 when this happens
 579     // this is what steppermotor does
 580     if(argument == 0) {
 581         this->stepper_motor->move(0, 0);
 582         this->current_block->release();
 583         this->current_block = NULL;
 584         return;
 585     }
 586
 587     /*
 588     * nominal block duration = current block's steps / ( current block's nominal rate )
 589     * nominal extruder rate = extruder steps / nominal block duration
 590     * actual extruder rate = nominal extruder rate * ( ( stepper's steps per second ) / ( current block's nominal rate ) )
 591     * or actual extruder rate = ( ( extruder steps * ( current block's nominal_rate ) ) / current block's steps ) * ( ( stepper's steps per second ) / ( current block's nominal rate ) )
 592     * or simplified : extruder steps * ( stepper's steps per second ) ) / current block's steps
 593     * or even : ( stepper steps per second ) * ( extruder steps / current block's steps )
 594     */
 595
 596     //this->stepper_motor->set_speed(THEKERNEL->stepper->get_trapezoid_adjusted_rate() * (float)this->stepper_motor->get_steps_to_move() / (float)this->current_block->steps_event_count);
 597     this->stepper_motor->set_step_rate(THEKERNEL->stepper->get_trapezoid_adjusted_rate(), (float)this->current_block->steps_event_count);
 598 }
 599
 600 // When the stepper has finished it's move
 601 uint32_t Extruder::stepper_motor_finished_move(uint32_t dummy)
 602 {
 603     if(!this->enabled) return 0;
 604
 605     //printf("extruder releasing\r\n");
 606
 607     if (this->current_block) { // this should always be true, but sometimes it isn't. TODO: find out why
 608         Block *block = this->current_block;
 609         this->current_block = NULL;
 610         block->release();
 611     }
 612     return 0;
 613
 614 }