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 // TODO : THIS FILE IS LAME, MUST BE MADE MUCH BETTER
   9
  10 #include "libs/Module.h"
  11 #include "libs/Kernel.h"
  12 #include <math.h>
  13 #include "TemperatureControl.h"
  14 #include "libs/Pin.h"
  15
  16 TemperatureControl::TemperatureControl(){}
  17
  18 TemperatureControl::TemperatureControl(uint16_t name){
  19     this->name_checksum = name;
  20     this->error_count = 0;
  21     this->waiting = false;
  22 }
  23
  24 void TemperatureControl::on_module_loaded(){
  25
  26     // We start not desiring any temp
  27     this->desired_adc_value = UNDEFINED;
  28
  29     // Settings
  30     this->on_config_reload(this);
  31
  32     this->acceleration_factor = 10;
  33
  34     this->kernel->slow_ticker->attach( 20, this, &TemperatureControl::thermistor_read_tick );
  35
  36     // Register for events
  37     this->register_for_event(ON_GCODE_EXECUTE);
  38     this->register_for_event(ON_MAIN_LOOP);
  39
  40 }
  41
  42 void TemperatureControl::on_main_loop(void* argument){ }
  43
  44 // Get configuration from the config file
  45 void TemperatureControl::on_config_reload(void* argument){
  46
  47     // General config
  48     this->set_m_code          = this->kernel->config->value(temperature_control_checksum, this->name_checksum, set_m_code_checksum)->by_default(104)->as_number();
  49     this->set_and_wait_m_code = this->kernel->config->value(temperature_control_checksum, this->name_checksum, set_and_wait_m_code_checksum)->by_default(109)->as_number();
  50     this->get_m_code          = this->kernel->config->value(temperature_control_checksum, this->name_checksum, get_m_code_checksum)->by_default(105)->as_number();
  51     this->readings_per_second = this->kernel->config->value(temperature_control_checksum, this->name_checksum, readings_per_second_checksum)->by_default(5)->as_number();
  52
  53     // Values are here : http://reprap.org/wiki/Thermistor
  54     this->r0   = 100000;
  55     this->t0   = 25;
  56     this->beta = 4066;
  57     this->vadc = 3.3;
  58     this->vcc  = 3.3;
  59     this->r1   = 0;
  60     this->r2   = 4700;
  61
  62     // Preset values for various common types of thermistors
  63     ConfigValue* thermistor = this->kernel->config->value(temperature_control_checksum, this->name_checksum, thermistor_checksum);
  64     if(       thermistor->value.compare("EPCOS100K"    ) == 0 ){ // Default
  65     }else if( thermistor->value.compare("RRRF100K"     ) == 0 ){ this->beta = 3960;
  66     }else if( thermistor->value.compare("RRRF10K"      ) == 0 ){ this->beta = 3964; this->r0 = 10000; this->r1 = 680; this->r2 = 1600;
  67     }else if( thermistor->value.compare("Honeywell100K") == 0 ){ this->beta = 3974;
  68     }else if( thermistor->value.compare("Semitec"      ) == 0 ){ this->beta = 4267; }
  69
  70     // Preset values are overriden by specified values
  71     this->r0 =                  this->kernel->config->value(temperature_control_checksum, this->name_checksum, r0_checksum  )->by_default(100000)->as_number();               // Stated resistance eg. 100K
  72     this->t0 =                  this->kernel->config->value(temperature_control_checksum, this->name_checksum, t0_checksum  )->by_default(25    )->as_number() + 273.15;      // Temperature at stated resistance, eg. 25C
  73     this->beta =                this->kernel->config->value(temperature_control_checksum, this->name_checksum, beta_checksum)->by_default(4066  )->as_number();               // Thermistor beta rating. See http://reprap.org/bin/view/Main/MeasuringThermistorBeta
  74     this->vadc =                this->kernel->config->value(temperature_control_checksum, this->name_checksum, vadc_checksum)->by_default(3.3   )->as_number();               // ADC Reference
  75     this->vcc  =                this->kernel->config->value(temperature_control_checksum, this->name_checksum, vcc_checksum )->by_default(3.3   )->as_number();               // Supply voltage to potential divider
  76     this->r1 =                  this->kernel->config->value(temperature_control_checksum, this->name_checksum, r1_checksum  )->by_default(0     )->as_number();
  77     this->r2 =                  this->kernel->config->value(temperature_control_checksum, this->name_checksum, r2_checksum  )->by_default(4700  )->as_number();
  78
  79     // Thermistor math
  80     this->k = this->r0 * exp( -this->beta / this->t0 );
  81     if( r1 > 0 ){ this->vs = r1 * this->vcc / ( r1 + r2 ); this->rs = r1 * r2 / ( r1 + r2 ); }else{ this->vs = this->vcc; this->rs = r2; }
  82
  83     // Thermistor pin for ADC readings
  84     this->thermistor_pin = this->kernel->config->value(temperature_control_checksum, this->name_checksum, thermistor_pin_checksum )->required()->as_pin();
  85     this->kernel->adc->enable_pin(this->thermistor_pin);
  86
  87     // Heater pin
  88     this->heater_pin     =  this->kernel->config->value(temperature_control_checksum, this->name_checksum, heater_pin_checksum)->required()->as_pin()->as_output();
  89     this->heater_pin->set(0);
  90
  91 }
  92
  93 void TemperatureControl::on_gcode_execute(void* argument){
  94     Gcode* gcode = static_cast<Gcode*>(argument);
  95
  96
  97     //gcode->stream->printf("%u %u %u \r\n",gcode->has_letter('M'), (gcode->get_value('M') == 104), gcode->has_letter('S') );
  98
  99     // Set temperature without waiting
 100     if( gcode->has_letter('M') && gcode->get_value('M') == this->set_m_code && gcode->has_letter('S') ){
 101         //gcode->stream->printf("setting to %f meaning %u  \r\n", gcode->get_value('S'), this->temperature_to_adc_value( gcode->get_value('S') ) );
 102         this->set_desired_temperature(gcode->get_value('S'));
 103     }
 104
 105     // Set temperature and wait
 106     if( gcode->has_letter('M') && gcode->get_value('M') == this->set_and_wait_m_code && gcode->has_letter('S') ){
 107         this->set_desired_temperature(gcode->get_value('S'));
 108
 109         // Pause
 110         this->kernel->pauser->take();
 111         this->waiting = true;
 112
 113     }
 114
 115     // Get temperature
 116     if( gcode->has_letter('M') && gcode->get_value('M') == this->get_m_code ){
 117         gcode->stream->printf("get temperature: %f current:%f target:%f bare_value:%u \r\n", this->get_temperature(), this->new_thermistor_reading(), this->desired_adc_value, this->kernel->adc->read(this->thermistor_pin)  );
 118     }
 119 }
 120
 121 void TemperatureControl::set_desired_temperature(double desired_temperature){
 122     this->desired_adc_value = this->temperature_to_adc_value(desired_temperature);
 123 }
 124
 125 double TemperatureControl::get_temperature(){
 126     double temp = this->new_thermistor_reading() ;
 127     return this->adc_value_to_temperature( this->new_thermistor_reading() );
 128 }
 129
 130 double TemperatureControl::adc_value_to_temperature(double adc_value){
 131     double v = adc_value * this->vadc;            // Convert from 0-1 adc value to voltage
 132     double r = this->rs * v / ( this->vs - v );   // Resistance of thermistor
 133     return ( this->beta / log( r / this->k )) - 273.15;
 134 }
 135
 136 double TemperatureControl::temperature_to_adc_value(double temperature){
 137     double r = this->r0 * exp( this->beta * ( 1 / (temperature + 273.15) -1 / this->t0 ) ); // Resistance of the thermistor
 138     double v = this->vs * r / ( this->rs + r );                                             // Voltage at the potential divider
 139     return v / this->vadc * 1.00000;                                               // The ADC reading
 140 }
 141
 142 uint32_t TemperatureControl::thermistor_read_tick(uint32_t dummy){
 143     if( this->desired_adc_value != UNDEFINED ){
 144         if( this->new_thermistor_reading() > this->desired_adc_value ){
 145             this->heater_pin->set(1);
 146         }else{
 147             this->heater_pin->set(0);
 148             if( this->waiting ){
 149                 this->kernel->pauser->release();
 150                 this->waiting = false;
 151             }
 152         }
 153     }
 154 }
 155
 156 double TemperatureControl::new_thermistor_reading(){
 157
 158     double new_reading = double( double(this->kernel->adc->read(this->thermistor_pin) / double(1<<12) ) );
 159
 160     if( this->queue.size() < 15 ){
 161         this->queue.push_back( new_reading );
 162         return new_reading;
 163     }else{
 164         double current_temp = this->average_adc_reading();
 165         double error = fabs(new_reading - current_temp);
 166         if( error < 0.1 ){
 167             this->error_count = 0;
 168             double test;
 169             this->queue.pop_front(test);
 170             this->queue.push_back( new_reading );
 171         }else{
 172             this->error_count++;
 173             if( this->error_count > 4 ){
 174                 double test;
 175                 this->queue.pop_front(test);
 176             }
 177         }
 178         return current_temp;
 179     }
 180 }
 181
 182
 183 double TemperatureControl::average_adc_reading(){
 184     double total;
 185     int j=0;
 186     int reading_index = this->queue.head;
 187     while( reading_index != this->queue.tail ){
 188         j++;
 189         total += this->queue.buffer[reading_index];
 190         reading_index = this->queue.next_block_index( reading_index );
 191     }
 192     return total / j;
 193 }
 194
 195
 196