src/modules/tools/temperaturecontrol/AD8495.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 "AD8495.h"
   9 #include "libs/Kernel.h"
  10 #include "libs/Pin.h"
  11 #include "Config.h"
  12 #include "checksumm.h"
  13 #include "Adc.h"
  14 #include "ConfigValue.h"
  15 #include "libs/Median.h"
  16 #include "utils.h"
  17 #include "StreamOutputPool.h"
  18
  19 #include <fastmath.h>
  20
  21 #include "MRI_Hooks.h"
  22
  23 #define UNDEFINED -1
  24
  25 #define AD8495_pin_checksum            CHECKSUM("ad8495_pin")
  26 #define AD8495_offset_checksum         CHECKSUM("ad8495_offset")
  27
  28 AD8495::AD8495()
  29 {
  30     min_temp= 999;
  31     max_temp= 0;
  32 }
  33
  34 AD8495::~AD8495()
  35 {
  36 }
  37
  38 // Get configuration from the config file
  39 void AD8495::UpdateConfig(uint16_t module_checksum, uint16_t name_checksum)
  40 {
  41     // Thermistor pin for ADC readings
  42     this->AD8495_pin.from_string(THEKERNEL->config->value(module_checksum, name_checksum, AD8495_pin_checksum)->required()->as_string());
  43     this->AD8495_offset = THEKERNEL->config->value(module_checksum, name_checksum, AD8495_offset_checksum)->by_default(0)->as_number(); // Stated offset. For Adafruit board it is 250C. If pin 2(REF) of amplifier is connected to 0V then there is 0C offset.
  44
  45     THEKERNEL->adc->enable_pin(&AD8495_pin);
  46 }
  47
  48
  49 float AD8495::get_temperature()
  50 {
  51     float t= adc_value_to_temperature(new_AD8495_reading());
  52     // keep track of min/max for M305
  53     if(t > max_temp) max_temp= t;
  54     if(t < min_temp) min_temp= t;
  55     return t;
  56 }
  57
  58 void AD8495::get_raw()
  59 {
  60
  61     int adc_value= new_AD8495_reading();
  62     const uint32_t max_adc_value= THEKERNEL->adc->get_max_value();
  63     float t=((float)adc_value)/(((float)max_adc_value)/3.3*0.005);
  64
  65     t = t - this->AD8495_offset;
  66
  67     THEKERNEL->streams->printf("adc= %d, max_adc= %lu, temp= %f, offset = %f\n", adc_value,max_adc_value,t, this->AD8495_offset);
  68
  69     // reset the min/max
  70     min_temp= max_temp= t;
  71 }
  72
  73 float AD8495::adc_value_to_temperature(uint32_t adc_value)
  74 {
  75     const uint32_t max_adc_value= THEKERNEL->adc->get_max_value();
  76     if ((adc_value >= max_adc_value))
  77         return infinityf();
  78
  79     float t=((float)adc_value)/(((float)max_adc_value)/3.3*0.005);
  80
  81     t=t-this->AD8495_offset;
  82
  83     return t;
  84 }
  85
  86 int AD8495::new_AD8495_reading()
  87 {
  88     // filtering now done in ADC
  89     return THEKERNEL->adc->read(&AD8495_pin);
  90 }