src/modules/tools/temperaturecontrol/TemperatureControl.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 "libs/Module.h"
   9 #include "libs/Kernel.h"
  10 #include <math.h>
  11 #include "TemperatureControl.h"
  12 #include "TemperatureControlPool.h"
  13 #include "libs/Pin.h"
  14 #include "modules/robot/Conveyor.h"
  15 #include "PublicDataRequest.h"
  16
  17 #include "PublicData.h"
  18 #include "ToolManagerPublicAccess.h"
  19 #include "StreamOutputPool.h"
  20 #include "Config.h"
  21 #include "checksumm.h"
  22 #include "Gcode.h"
  23 #include "SlowTicker.h"
  24 #include "ConfigValue.h"
  25 #include "PID_Autotuner.h"
  26 #include "SerialMessage.h"
  27 #include "utils.h"
  28
  29 // Temp sensor implementations:
  30 #include "Thermistor.h"
  31 #include "max31855.h"
  32 #include "AD8495.h"
  33 #include "PT100_E3D.h"
  34
  35 #include "MRI_Hooks.h"
  36
  37 #define UNDEFINED -1
  38
  39 #define sensor_checksum                    CHECKSUM("sensor")
  40
  41 #define readings_per_second_checksum       CHECKSUM("readings_per_second")
  42 #define max_pwm_checksum                   CHECKSUM("max_pwm")
  43 #define pwm_frequency_checksum             CHECKSUM("pwm_frequency")
  44 #define bang_bang_checksum                 CHECKSUM("bang_bang")
  45 #define hysteresis_checksum                CHECKSUM("hysteresis")
  46 #define heater_pin_checksum                CHECKSUM("heater_pin")
  47 #define max_temp_checksum                  CHECKSUM("max_temp")
  48 #define min_temp_checksum                  CHECKSUM("min_temp")
  49
  50 #define get_m_code_checksum                CHECKSUM("get_m_code")
  51 #define set_m_code_checksum                CHECKSUM("set_m_code")
  52 #define set_and_wait_m_code_checksum       CHECKSUM("set_and_wait_m_code")
  53
  54 #define designator_checksum                CHECKSUM("designator")
  55
  56 #define p_factor_checksum                  CHECKSUM("p_factor")
  57 #define i_factor_checksum                  CHECKSUM("i_factor")
  58 #define d_factor_checksum                  CHECKSUM("d_factor")
  59
  60 #define i_max_checksum                     CHECKSUM("i_max")
  61 #define windup_checksum                    CHECKSUM("windup")
  62
  63 #define preset1_checksum                   CHECKSUM("preset1")
  64 #define preset2_checksum                   CHECKSUM("preset2")
  65
  66 #define runaway_range_checksum             CHECKSUM("runaway_range")
  67 #define runaway_heating_timeout_checksum   CHECKSUM("runaway_heating_timeout")
  68 #define runaway_cooling_timeout_checksum   CHECKSUM("runaway_cooling_timeout")
  69 #define runaway_error_range_checksum       CHECKSUM("runaway_error_range")
  70
  71 TemperatureControl::TemperatureControl(uint16_t name, int index)
  72 {
  73     name_checksum= name;
  74     pool_index= index;
  75     waiting= false;
  76     temp_violated= false;
  77     sensor= nullptr;
  78     readonly= false;
  79     tick= 0;
  80 }
  81
  82 TemperatureControl::~TemperatureControl()
  83 {
  84     delete sensor;
  85 }
  86
  87 void TemperatureControl::on_module_loaded()
  88 {
  89
  90     // We start not desiring any temp
  91     this->target_temperature = UNDEFINED;
  92     this->sensor_settings= false; // set to true if sensor settings have been overriden
  93
  94     // Settings
  95     this->load_config();
  96
  97     // Register for events
  98     this->register_for_event(ON_GCODE_RECEIVED);
  99     this->register_for_event(ON_GET_PUBLIC_DATA);
 100     this->register_for_event(ON_IDLE);
 101
 102     if(!this->readonly) {
 103         this->register_for_event(ON_SECOND_TICK);
 104         this->register_for_event(ON_MAIN_LOOP);
 105         this->register_for_event(ON_SET_PUBLIC_DATA);
 106         this->register_for_event(ON_HALT);
 107     }
 108 }
 109
 110 void TemperatureControl::on_halt(void *arg)
 111 {
 112     if(arg == nullptr) {
 113         // turn off heater
 114         this->o = 0;
 115         this->heater_pin.set(0);
 116         this->target_temperature = UNDEFINED;
 117     }
 118 }
 119
 120 void TemperatureControl::on_idle(void *arg)
 121 {
 122     sensor->on_idle();
 123 }
 124
 125
 126 void TemperatureControl::on_main_loop(void *argument)
 127 {
 128     if (this->temp_violated) {
 129         this->temp_violated = false;
 130         THEKERNEL->streams->printf("ERROR: MINTEMP or MAXTEMP triggered on %s. Check your temperature sensors!\n", designator.c_str());
 131         THEKERNEL->streams->printf("HALT asserted - reset or M999 required\n");
 132         THEKERNEL->call_event(ON_HALT, nullptr);
 133     }
 134 }
 135
 136 // Get configuration from the config file
 137 void TemperatureControl::load_config()
 138 {
 139
 140     // General config
 141     this->set_m_code          = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, set_m_code_checksum)->by_default(104)->as_number();
 142     this->set_and_wait_m_code = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, set_and_wait_m_code_checksum)->by_default(109)->as_number();
 143     this->get_m_code          = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, get_m_code_checksum)->by_default(105)->as_number();
 144     this->readings_per_second = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, readings_per_second_checksum)->by_default(20)->as_number();
 145
 146     this->designator          = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, designator_checksum)->by_default(string("T"))->as_string();
 147
 148     // Runaway parameters
 149     uint32_t n= THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, runaway_range_checksum)->by_default(20)->as_number();
 150     if(n > 63) n= 63;
 151     this->runaway_range= n;
 152
 153     // these need to fit in 9 bits after dividing by 8 so max is 4088 secs or 68 minutes
 154     n= THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, runaway_heating_timeout_checksum)->by_default(900)->as_number();
 155     if(n > 4088) n= 4088;
 156     this->runaway_heating_timeout = n/8; // we have 8 second ticks
 157     n= THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, runaway_cooling_timeout_checksum)->by_default(0)->as_number(); // disable by default
 158     if(n > 4088) n= 4088;
 159     this->runaway_cooling_timeout = n/8;
 160
 161     this->runaway_error_range= THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, runaway_error_range_checksum)->by_default(1.0F)->as_number();
 162
 163     // Max and min temperatures we are not allowed to get over (Safety)
 164     this->max_temp = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, max_temp_checksum)->by_default(300)->as_number();
 165     this->min_temp = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, min_temp_checksum)->by_default(0)->as_number();
 166
 167     // Heater pin
 168     this->heater_pin.from_string( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, heater_pin_checksum)->by_default("nc")->as_string());
 169     if(this->heater_pin.connected()){
 170         this->readonly= false;
 171         this->heater_pin.as_output();
 172
 173     } else {
 174         this->readonly= true;
 175     }
 176
 177     // For backward compatibility, default to a thermistor sensor.
 178     std::string sensor_type = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, sensor_checksum)->by_default("thermistor")->as_string();
 179
 180     // Instantiate correct sensor (TBD: TempSensor factory?)
 181     delete sensor;
 182     sensor = nullptr; // In case we fail to create a new sensor.
 183     if(sensor_type.compare("thermistor") == 0) {
 184         sensor = new Thermistor();
 185     } else if(sensor_type.compare("max31855") == 0) {
 186         sensor = new Max31855();
 187     } else if(sensor_type.compare("ad8495") == 0) {
 188         sensor = new AD8495();
 189     } else if(sensor_type.compare("pt100_e3d") == 0) {
 190         sensor = new PT100_E3D();
 191     } else {
 192         sensor = new TempSensor(); // A dummy implementation
 193     }
 194     sensor->UpdateConfig(temperature_control_checksum, this->name_checksum);
 195
 196     this->preset1 = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, preset1_checksum)->by_default(0)->as_number();
 197     this->preset2 = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, preset2_checksum)->by_default(0)->as_number();
 198
 199
 200     // sigma-delta output modulation
 201     this->o = 0;
 202
 203     if(!this->readonly) {
 204         // used to enable bang bang control of heater
 205         this->use_bangbang = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, bang_bang_checksum)->by_default(false)->as_bool();
 206         this->hysteresis = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, hysteresis_checksum)->by_default(2)->as_number();
 207         this->windup = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, windup_checksum)->by_default(false)->as_bool();
 208         this->heater_pin.max_pwm( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, max_pwm_checksum)->by_default(255)->as_number() );
 209         this->heater_pin.set(0);
 210         set_low_on_debug(heater_pin.port_number, heater_pin.pin);
 211         // activate SD-DAC timer
 212         THEKERNEL->slow_ticker->attach( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, pwm_frequency_checksum)->by_default(2000)->as_number(), &heater_pin, &Pwm::on_tick);
 213     }
 214
 215
 216     // reading tick
 217     THEKERNEL->slow_ticker->attach( this->readings_per_second, this, &TemperatureControl::thermistor_read_tick );
 218     this->PIDdt = 1.0 / this->readings_per_second;
 219
 220     // PID
 221     setPIDp( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, p_factor_checksum)->by_default(10 )->as_number() );
 222     setPIDi( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, i_factor_checksum)->by_default(0.3f)->as_number() );
 223     setPIDd( THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, d_factor_checksum)->by_default(200)->as_number() );
 224
 225     if(!this->readonly) {
 226         // set to the same as max_pwm by default
 227         this->i_max = THEKERNEL->config->value(temperature_control_checksum, this->name_checksum, i_max_checksum   )->by_default(this->heater_pin.max_pwm())->as_number();
 228     }
 229
 230     this->iTerm = 0.0;
 231     this->lastInput = -1.0;
 232     this->last_reading = 0.0;
 233 }
 234
 235 void TemperatureControl::on_gcode_received(void *argument)
 236 {
 237     Gcode *gcode = static_cast<Gcode *>(argument);
 238     if (gcode->has_m) {
 239
 240         if( gcode->m == this->get_m_code ) {
 241             char buf[32]; // should be big enough for any status
 242             int n = snprintf(buf, sizeof(buf), "%s:%3.1f /%3.1f @%d ", this->designator.c_str(), this->get_temperature(), ((target_temperature <= 0) ? 0.0 : target_temperature), this->o);
 243             gcode->txt_after_ok.append(buf, n);
 244             return;
 245         }
 246
 247         if (gcode->m == 305) { // set or get sensor settings
 248             if (gcode->has_letter('S') && (gcode->get_value('S') == this->pool_index)) {
 249                 TempSensor::sensor_options_t args= gcode->get_args();
 250                 args.erase('S'); // don't include the S
 251                 if(args.size() > 0) {
 252                     // set the new options
 253                     if(sensor->set_optional(args)) {
 254                         this->sensor_settings= true;
 255                     }else{
 256                         gcode->stream->printf("Unable to properly set sensor settings, make sure you specify all required values\n");
 257                     }
 258                 }else{
 259                     // don't override
 260                     this->sensor_settings= false;
 261                 }
 262
 263             }else if(!gcode->has_letter('S')) {
 264                 gcode->stream->printf("%s(S%d): using %s\n", this->designator.c_str(), this->pool_index, this->readonly?"Readonly" : this->use_bangbang?"Bangbang":"PID");
 265                 sensor->get_raw();
 266                 TempSensor::sensor_options_t options;
 267                 if(sensor->get_optional(options)) {
 268                     for(auto &i : options) {
 269                         // foreach optional value
 270                         gcode->stream->printf("%s(S%d): %c %1.18f\n", this->designator.c_str(), this->pool_index, i.first, i.second);
 271                     }
 272                 }
 273             }
 274
 275             return;
 276         }
 277
 278         // readonly sensors don't handle the rest
 279         if(this->readonly) return;
 280
 281         if (gcode->m == 143) {
 282             if (gcode->has_letter('S') && (gcode->get_value('S') == this->pool_index)) {
 283                 if(gcode->has_letter('P')) {
 284                     max_temp= gcode->get_value('P');
 285
 286                 } else {
 287                     gcode->stream->printf("Nothing set NOTE Usage is M143 S0 P300 where <S> is the hotend index and <P> is the maximum temp to set\n");
 288                 }
 289
 290             }else if(gcode->get_num_args() == 0) {
 291                 gcode->stream->printf("Maximum temperature for %s(%d) is %f°C\n", this->designator.c_str(), this->pool_index, max_temp);
 292             }
 293
 294         } else if (gcode->m == 301) {
 295             if (gcode->has_letter('S') && (gcode->get_value('S') == this->pool_index)) {
 296                 if (gcode->has_letter('P'))
 297                     setPIDp( gcode->get_value('P') );
 298                 if (gcode->has_letter('I'))
 299                     setPIDi( gcode->get_value('I') );
 300                 if (gcode->has_letter('D'))
 301                     setPIDd( gcode->get_value('D') );
 302                 if (gcode->has_letter('X'))
 303                     this->i_max = gcode->get_value('X');
 304                 if (gcode->has_letter('Y'))
 305                     this->heater_pin.max_pwm(gcode->get_value('Y'));
 306
 307             }else if(!gcode->has_letter('S')) {
 308                 gcode->stream->printf("%s(S%d): Pf:%g If:%g Df:%g X(I_max):%g Y(max pwm):%d O:%d\n", this->designator.c_str(), this->pool_index, this->p_factor, this->i_factor / this->PIDdt, this->d_factor * this->PIDdt, this->i_max, this->heater_pin.max_pwm(), o);
 309             }
 310
 311         } else if (gcode->m == 500 || gcode->m == 503) { // M500 saves some volatile settings to config override file, M503 just prints the settings
 312             gcode->stream->printf(";PID settings, i_max, max_pwm:\nM301 S%d P%1.4f I%1.4f D%1.4f X%1.4f Y%d\n", this->pool_index, this->p_factor, this->i_factor / this->PIDdt, this->d_factor * this->PIDdt, this->i_max, this->heater_pin.max_pwm());
 313
 314             gcode->stream->printf(";Max temperature setting:\nM143 S%d P%1.4f\n", this->pool_index, this->max_temp);
 315
 316             if(this->sensor_settings) {
 317                 // get or save any sensor specific optional values
 318                 TempSensor::sensor_options_t options;
 319                 if(sensor->get_optional(options) && !options.empty()) {
 320                     gcode->stream->printf(";Optional temp sensor specific settings:\nM305 S%d", this->pool_index);
 321                     for(auto &i : options) {
 322                         gcode->stream->printf(" %c%1.18f", i.first, i.second);
 323                     }
 324                     gcode->stream->printf("\n");
 325                 }
 326             }
 327
 328         } else if( ( gcode->m == this->set_m_code || gcode->m == this->set_and_wait_m_code ) && gcode->has_letter('S')) {
 329             int tool = gcode->has_letter('T') ? gcode->get_value('T') : -1;
 330             // default on when no T, for unmanaged tools (e.g. heatbed)
 331             bool am_tool = (tool == -1) ? true : false;
 332
 333             if (tool == -1) {
 334                 // this is safe as old configs as well as single extruder configs the toolmanager will not be running so will return false
 335                 // this will also ignore anything that the tool manager is not controlling and return false, otherwise it returns the active tool
 336                 void *returned_data;
 337                 bool ok = PublicData::get_value( tool_manager_checksum, is_active_tool_checksum, this->name_checksum, &returned_data );
 338                 if (ok) {
 339                     uint16_t active_tool_name =  *static_cast<uint16_t *>(returned_data);
 340                     am_tool = (active_tool_name == this->name_checksum);
 341                 }
 342             } else {
 343                 // FIXME
 344                 // this is wrong because we can't get the names of any
 345                 // inactive tools to check that we are associated with
 346                 // one. Just assume one temperature control per
 347                 // tool...
 348                 am_tool = (tool == this->pool_index);
 349             }
 350
 351             if(am_tool) {
 352                 // required so temp change happens in order
 353                 // Allow set without wait to be processed immediately
 354                 if( gcode->m == this->set_and_wait_m_code ) {
 355                     THEKERNEL->conveyor->wait_for_idle();
 356                 }
 357
 358                 float v = gcode->get_value('S');
 359
 360                 if (v == 0.0) {
 361                     this->target_temperature = UNDEFINED;
 362                     this->heater_pin.set((this->o = 0));
 363                 } else {
 364                     this->set_desired_temperature(v);
 365                     // wait for temp to be reached, no more gcodes will be fetched until this is complete
 366                     if( gcode->m == this->set_and_wait_m_code) {
 367                         if(isinf(get_temperature()) && isinf(sensor->get_temperature())) {
 368                             THEKERNEL->streams->printf("Temperature reading is unreliable on %s HALT asserted - reset or M999 required\n", designator.c_str());
 369                             THEKERNEL->call_event(ON_HALT, nullptr);
 370                             return;
 371                         }
 372
 373                         this->waiting = true; // on_second_tick will announce temps
 374                         while ( get_temperature() < target_temperature ) {
 375                             THEKERNEL->call_event(ON_IDLE, this);
 376                             // check if ON_HALT was called (usually by kill button)
 377                             if(THEKERNEL->is_halted() || this->target_temperature == UNDEFINED) {
 378                                 THEKERNEL->streams->printf("Wait on temperature aborted by kill\n");
 379                                 break;
 380                             }
 381                         }
 382                         this->waiting = false;
 383                     }
 384                 }
 385             }
 386         }
 387     }
 388 }
 389
 390 void TemperatureControl::on_get_public_data(void *argument)
 391 {
 392     PublicDataRequest *pdr = static_cast<PublicDataRequest *>(argument);
 393
 394     if(!pdr->starts_with(temperature_control_checksum)) return;
 395
 396     if(pdr->second_element_is(pool_index_checksum)) {
 397         // asking for our instance pointer if we have this pool_index
 398         if(pdr->third_element_is(this->pool_index)) {
 399             static void *return_data;
 400             return_data = this;
 401             pdr->set_data_ptr(&return_data);
 402             pdr->set_taken();
 403         }
 404
 405     }else if(pdr->second_element_is(poll_controls_checksum)) {
 406         // polling for all temperature controls
 407         // add our data to the list which is passed in via the data_ptr
 408
 409         std::vector<struct pad_temperature> *v= static_cast<std::vector<pad_temperature>*>(pdr->get_data_ptr());
 410
 411         struct pad_temperature t;
 412         // setup data
 413         t.current_temperature = this->get_temperature();
 414         t.target_temperature = (target_temperature <= 0) ? 0 : this->target_temperature;
 415         t.pwm = this->o;
 416         t.designator= this->designator;
 417         t.id= this->name_checksum;
 418         v->push_back(t);
 419         pdr->set_taken();
 420
 421     }else if(pdr->second_element_is(current_temperature_checksum)) {
 422         // if targeted at us
 423         if(pdr->third_element_is(this->name_checksum)) {
 424             // ok this is targeted at us, so set the requ3sted data in the pointer passed into us
 425             struct pad_temperature *t= static_cast<pad_temperature*>(pdr->get_data_ptr());
 426             t->current_temperature = this->get_temperature();
 427             t->target_temperature = (target_temperature <= 0) ? 0 : this->target_temperature;
 428             t->pwm = this->o;
 429             t->designator= this->designator;
 430             t->id= this->name_checksum;
 431             pdr->set_taken();
 432         }
 433     }
 434
 435 }
 436
 437 void TemperatureControl::on_set_public_data(void *argument)
 438 {
 439     PublicDataRequest *pdr = static_cast<PublicDataRequest *>(argument);
 440
 441     if(!pdr->starts_with(temperature_control_checksum)) return;
 442
 443     if(!pdr->second_element_is(this->name_checksum)) return;
 444
 445     // ok this is targeted at us, so set the temp
 446     // NOTE unlike the M code this will set the temp now not when the queue is empty
 447     float t = *static_cast<float *>(pdr->get_data_ptr());
 448     this->set_desired_temperature(t);
 449     pdr->set_taken();
 450 }
 451
 452 void TemperatureControl::set_desired_temperature(float desired_temperature)
 453 {
 454     // Never go over the configured max temperature
 455     if( desired_temperature > this->max_temp ){
 456         desired_temperature = this->max_temp;
 457     }
 458
 459     if (desired_temperature == 1.0F)
 460         desired_temperature = preset1;
 461     else if (desired_temperature == 2.0F)
 462         desired_temperature = preset2;
 463
 464     float last_target_temperature= target_temperature;
 465     target_temperature = desired_temperature;
 466     if (desired_temperature <= 0.0F){
 467         // turning it off
 468         heater_pin.set((this->o = 0));
 469
 470     }else if(last_target_temperature <= 0.0F) {
 471         // if it was off and we are now turning it on we need to initialize
 472         this->lastInput= last_reading;
 473         // set to whatever the output currently is See http://brettbeauregard.com/blog/2011/04/improving-the-beginner%E2%80%99s-pid-initialization/
 474         this->iTerm= this->o;
 475         if (this->iTerm > this->i_max) this->iTerm = this->i_max;
 476         else if (this->iTerm < 0.0) this->iTerm = 0.0;
 477     }
 478
 479     // reset the runaway state, even if it was a temp change
 480     this->runaway_state = NOT_HEATING;
 481 }
 482
 483 float TemperatureControl::get_temperature()
 484 {
 485     return last_reading;
 486 }
 487
 488 uint32_t TemperatureControl::thermistor_read_tick(uint32_t dummy)
 489 {
 490     float temperature = sensor->get_temperature();
 491     if(!this->readonly && target_temperature > 2) {
 492         if (isinf(temperature) || temperature < min_temp || temperature > max_temp) {
 493             this->temp_violated = true;
 494             target_temperature = UNDEFINED;
 495             heater_pin.set((this->o = 0));
 496         } else {
 497             pid_process(temperature);
 498         }
 499     }
 500
 501     last_reading = temperature;
 502     return 0;
 503 }
 504
 505 /**
 506  * Based on https://github.com/br3ttb/Arduino-PID-Library
 507  */
 508 void TemperatureControl::pid_process(float temperature)
 509 {
 510     if(use_bangbang) {
 511         // bang bang is very simple, if temp is < target - hysteresis turn on full else if  temp is > target + hysteresis turn heater off
 512         // good for relays
 513         if(temperature > (target_temperature + hysteresis) && this->o > 0) {
 514             heater_pin.set(false);
 515             this->o = 0; // for display purposes only
 516
 517         } else if(temperature < (target_temperature - hysteresis) && this->o <= 0) {
 518             if(heater_pin.max_pwm() >= 255) {
 519                 // turn on full
 520                 this->heater_pin.set(true);
 521                 this->o = 255; // for display purposes only
 522             } else {
 523                 // only to whatever max pwm is configured
 524                 this->heater_pin.pwm(heater_pin.max_pwm());
 525                 this->o = heater_pin.max_pwm(); // for display purposes only
 526             }
 527         }
 528         return;
 529     }
 530
 531     // regular PID control
 532     float error = target_temperature - temperature;
 533
 534     float new_I = this->iTerm + (error * this->i_factor);
 535     if (new_I > this->i_max) new_I = this->i_max;
 536     else if (new_I < 0.0) new_I = 0.0;
 537     if(!this->windup) this->iTerm= new_I;
 538
 539     float d = (temperature - this->lastInput);
 540
 541     // calculate the PID output
 542     // TODO does this need to be scaled by max_pwm/256? I think not as p_factor already does that
 543     this->o = (this->p_factor * error) + new_I - (this->d_factor * d);
 544
 545     if (this->o >= heater_pin.max_pwm())
 546         this->o = heater_pin.max_pwm();
 547     else if (this->o < 0)
 548         this->o = 0;
 549     else if(this->windup)
 550         this->iTerm = new_I; // Only update I term when output is not saturated.
 551
 552     this->heater_pin.pwm(this->o);
 553     this->lastInput = temperature;
 554 }
 555
 556 void TemperatureControl::on_second_tick(void *argument)
 557 {
 558
 559     // If waiting for a temperature to be reach, display it to keep host programs up to date on the progress
 560     if (waiting)
 561         THEKERNEL->streams->printf("%s:%3.1f /%3.1f @%d\n", designator.c_str(), get_temperature(), ((target_temperature <= 0) ? 0.0 : target_temperature), o);
 562
 563     // Check whether or not there is a temperature runaway issue, if so stop everything and report it
 564     if(THEKERNEL->is_halted()) return;
 565
 566     // see if runaway detection is enabled
 567     if(this->runaway_heating_timeout == 0 && this->runaway_range == 0) return;
 568
 569     // check every 8 seconds, depends on tick being 3 bits
 570     if(++tick != 0) return;
 571
 572     if(this->target_temperature <= 0){ // If we are not trying to heat, state is NOT_HEATING
 573         this->runaway_state = NOT_HEATING;
 574
 575     }else{
 576         float current_temperature= this->get_temperature();
 577         // heater is active
 578         switch( this->runaway_state ){
 579             case NOT_HEATING: // If we were previously not trying to heat, but we are now, change to state WAITING_FOR_TEMP_TO_BE_REACHED
 580                 this->runaway_state= (this->target_temperature >= current_temperature || this->runaway_cooling_timeout == 0) ? HEATING_UP : COOLING_DOWN;
 581                 this->runaway_timer = 0;
 582                 tick= 0;
 583                 break;
 584
 585             case HEATING_UP:
 586             case COOLING_DOWN:
 587                 // check temp has reached the target temperature within the given error range
 588                 if( (runaway_state == HEATING_UP && current_temperature >= (this->target_temperature - this->runaway_error_range)) ||
 589                     (runaway_state == COOLING_DOWN && current_temperature <= (this->target_temperature + this->runaway_error_range)) ) {
 590                     this->runaway_state = TARGET_TEMPERATURE_REACHED;
 591                     this->runaway_timer = 0;
 592                     tick= 0;
 593
 594                 }else{
 595                     uint16_t t= (runaway_state == HEATING_UP) ? this->runaway_heating_timeout : this->runaway_cooling_timeout;
 596                     // we are still heating up see if we have hit the max time allowed
 597                     if(t > 0 && ++this->runaway_timer > t){
 598                         THEKERNEL->streams->printf("ERROR: Temperature took too long to be reached on %s, HALT asserted, TURN POWER OFF IMMEDIATELY - reset or M999 required\n", designator.c_str());
 599                         THEKERNEL->call_event(ON_HALT, nullptr);
 600                         this->runaway_state = NOT_HEATING;
 601                         this->runaway_timer = 0;
 602                     }
 603                 }
 604                 break;
 605
 606             case TARGET_TEMPERATURE_REACHED:
 607                 if(this->runaway_range != 0) {
 608                     // we are in state TARGET_TEMPERATURE_REACHED, check for thermal runaway
 609                     float delta= current_temperature - this->target_temperature;
 610
 611                     // If the temperature is outside the acceptable range for 8 seconds, this allows for some noise spikes without halting
 612                     if(fabsf(delta) > this->runaway_range){
 613                         if(this->runaway_timer++ >= 1) { // this being 8 seconds
 614                             THEKERNEL->streams->printf("ERROR: Temperature runaway on %s (delta temp %f), HALT asserted, TURN POWER OFF IMMEDIATELY - reset or M999 required\n", designator.c_str(), delta);
 615                             THEKERNEL->call_event(ON_HALT, nullptr);
 616                             this->runaway_state = NOT_HEATING;
 617                             this->runaway_timer= 0;
 618                         }
 619
 620                     }else{
 621                         this->runaway_timer= 0;
 622                     }
 623                 }
 624
 625                 break;
 626         }
 627     }
 628 }
 629
 630 void TemperatureControl::setPIDp(float p)
 631 {
 632     this->p_factor = p;
 633 }
 634
 635 void TemperatureControl::setPIDi(float i)
 636 {
 637     this->i_factor = i * this->PIDdt;
 638 }
 639
 640 void TemperatureControl::setPIDd(float d)
 641 {
 642     this->d_factor = d / this->PIDdt;
 643 }