Ollie Matthews / Heater

Heater for threaded program

Dependents:   LEX_Threaded_Programming

Heater.cpp@18:f5d26d3d532f, 2019-07-28 (annotated)

Committer:
omatthews
Date:
Sun Jul 28 11:49:57 2019 +0000
Revision:
18:f5d26d3d532f
Parent:
17:0bfed0e96927
Child:
19:fccdd7127f94
Added in consts

Who changed what in which revision?

UserRevisionLine numberNew contents of line
omatthews 0:4e33cc8171f4 1 /*------------------------------------------------------------------------------
omatthews 0:4e33cc8171f4 2 Library code file for interface to Heater
omatthews 0:4e33cc8171f4 3 Date: 16/07/2018
omatthews 0:4e33cc8171f4 4
omatthews 0:4e33cc8171f4 5
omatthews 0:4e33cc8171f4 6 ------------------------------------------------------------------------------*/
omatthews 1:4435d407d827 7 #include "mbed.h"
omatthews 1:4435d407d827 8 #include "MODSERIAL.h"
omatthews 0:4e33cc8171f4 9 #include "Heater.h"
omatthews 0:4e33cc8171f4 10 #include "ADS8568_ADC.h"
omatthews 0:4e33cc8171f4 11
omatthews 0:4e33cc8171f4 12 extern ADS8568_ADC adc;
omatthews 0:4e33cc8171f4 13 extern Timer timer;
omatthews 1:4435d407d827 14 extern DigitalIn adc_busy;
omatthews 1:4435d407d827 15 extern MODSERIAL pc;
omatthews 11:785a0329f802 16 extern int log_count;
omatthews 11:785a0329f802 17 extern float R_avg;
omatthews 1:4435d407d827 18
omatthews 0:4e33cc8171f4 19
omatthews 0:4e33cc8171f4 20
omatthews 18:f5d26d3d532f 21 Heater::Heater(const int i_port, const int v_port, FastPWM * drive, const float corr_grad, const float corr_int, float R_ref)
omatthews 8:5da71ae16115 22 :R_ref(R_ref),i_port(i_port),v_port(v_port),drive(drive),corr_grad(corr_grad),corr_int(corr_int) {}
omatthews 7:59ece353eea2 23
omatthews 0:4e33cc8171f4 24
omatthews 18:f5d26d3d532f 25 // Convert from R to T using the linear relationship - T = R * corr_grad + corr_int
omatthews 18:f5d26d3d532f 26 float Heater::R_to_T(const float R) const {return R*corr_grad + corr_int;}
omatthews 18:f5d26d3d532f 27 float Heater::T_to_R(const float T) const {return (T - corr_int)/corr_grad;}
omatthews 18:f5d26d3d532f 28
omatthews 18:f5d26d3d532f 29 void Heater::output()const
omatthews 11:785a0329f802 30 {
omatthews 18:f5d26d3d532f 31 //Prints the current state to the terminal
omatthews 17:0bfed0e96927 32 pc.printf("%d,%f,%f,%f,%f,%f\n",timer.read_ms(),R_ref,R,error,error_integrated,drive->read());
omatthews 11:785a0329f802 33 }
omatthews 0:4e33cc8171f4 34
omatthews 2:7f15386fcc90 35 void Heater::read()
omatthews 0:4e33cc8171f4 36 {
omatthews 1:4435d407d827 37 //Reads R and then resets the drive back to its previous value
omatthews 17:0bfed0e96927 38
omatthews 1:4435d407d827 39 int i = 0;
omatthews 18:f5d26d3d532f 40 //float error_prev = error;
omatthews 17:0bfed0e96927 41
omatthews 17:0bfed0e96927 42 double drive_prev = drive->read(); //Store previous value of drive
omatthews 18:f5d26d3d532f 43 drive->period_us(1); //Set period to 1us for the measurement
omatthews 18:f5d26d3d532f 44 *drive = 1.0f; //Turn the driver on for the measurement
omatthews 7:59ece353eea2 45 wait_us(MEAS_DELAY); //Wait for ADC to settle
omatthews 1:4435d407d827 46 adc.start_conversion(ALL_CH);
omatthews 18:f5d26d3d532f 47 //Incremental back off until ADC is free
omatthews 1:4435d407d827 48 while(adc_busy == 1)
omatthews 1:4435d407d827 49 {
omatthews 1:4435d407d827 50 wait_us(1);
omatthews 1:4435d407d827 51 i++;
omatthews 18:f5d26d3d532f 52 }
omatthews 18:f5d26d3d532f 53 drive->write(drive_prev); //Reset the duty cycle back to what it was
omatthews 18:f5d26d3d532f 54 drive->period_us(PWM_PERIOD); //Reset the period to what it was
omatthews 17:0bfed0e96927 55
omatthews 18:f5d26d3d532f 56
omatthews 18:f5d26d3d532f 57 //Get voltage, current and R values from the ADC conversion
omatthews 0:4e33cc8171f4 58 adc.read_channels();
omatthews 7:59ece353eea2 59 curr = adc.read_channel_result(i_port);
omatthews 7:59ece353eea2 60 v = adc.read_channel_result(v_port);
omatthews 18:f5d26d3d532f 61
omatthews 17:0bfed0e96927 62 if (curr > 0) {R = (float)v/curr;} //Avoid dividing by 0
omatthews 12:8a048f111140 63
omatthews 18:f5d26d3d532f 64 //Get error values
omatthews 18:f5d26d3d532f 65
omatthews 17:0bfed0e96927 66 error = R_ref - R;
omatthews 18:f5d26d3d532f 67 //error_diff = (error - error_prev)/WAIT_DELAY;
omatthews 14:f266bf960b8d 68
omatthews 18:f5d26d3d532f 69 //Avoid integral windup by limiting integral error past actuation saturation
omatthews 17:0bfed0e96927 70 if (error*Kp > WIND_UP_LIMIT) {error_integrated += WIND_UP_LIMIT/Kp;}
omatthews 17:0bfed0e96927 71 else if (error*Kp < -WIND_UP_LIMIT) {error_integrated -= WIND_UP_LIMIT/Kp;}
omatthews 17:0bfed0e96927 72 else {error_integrated += error;}
omatthews 14:f266bf960b8d 73
omatthews 14:f266bf960b8d 74
omatthews 18:f5d26d3d532f 75 //Output the error every LOG_LIM reads
omatthews 11:785a0329f802 76 log_count++;
omatthews 18:f5d26d3d532f 77 if (log_count >= LOG_LIM)
omatthews 11:785a0329f802 78 {
omatthews 11:785a0329f802 79 log_count = 0;
omatthews 11:785a0329f802 80 output();
omatthews 11:785a0329f802 81 }
omatthews 0:4e33cc8171f4 82 }
omatthews 0:4e33cc8171f4 83
omatthews 2:7f15386fcc90 84
omatthews 2:7f15386fcc90 85
omatthews 2:7f15386fcc90 86
omatthews 18:f5d26d3d532f 87 void Heater::hold(const int hold_time)
omatthews 0:4e33cc8171f4 88 {
omatthews 7:59ece353eea2 89 //Holds the heater at R_ref for the given hold time
omatthews 7:59ece353eea2 90 // in: int hold_time - is the time in ms to hold the reference
omatthews 7:59ece353eea2 91
omatthews 0:4e33cc8171f4 92 int end_time = timer.read_ms() + hold_time;
omatthews 1:4435d407d827 93 while (timer.read_ms() < end_time)
omatthews 0:4e33cc8171f4 94 {
omatthews 2:7f15386fcc90 95 read();
omatthews 17:0bfed0e96927 96 drive->write((double) (Kp * (error + error_integrated/Ti)));
omatthews 18:f5d26d3d532f 97 wait_ms(WAIT_DELAY); //Wait before reading again
omatthews 0:4e33cc8171f4 98 }
omatthews 1:4435d407d827 99 }
omatthews 1:4435d407d827 100
omatthews 0:4e33cc8171f4 101
omatthews 18:f5d26d3d532f 102 void Heater::ramp_R(const int ramp_time, const float R_final, const float R_start)
omatthews 7:59ece353eea2 103 {
omatthews 18:f5d26d3d532f 104 //Ramps the heater from R_start to R_final for the given hold time
omatthews 18:f5d26d3d532f 105 // in: int hold_time - is the time in ms to hold the reference
omatthews 18:f5d26d3d532f 106 // float R_final - is the final R_ref value
omatthews 18:f5d26d3d532f 107 // float R_start - is the initial R_ref value
omatthews 18:f5d26d3d532f 108
omatthews 8:5da71ae16115 109 int time = timer.read_ms();
omatthews 8:5da71ae16115 110 int start_time = time;
omatthews 7:59ece353eea2 111 int end_time = start_time + ramp_time;
omatthews 7:59ece353eea2 112 float ramp_rate = (R_final - R_start)/ramp_time;
omatthews 7:59ece353eea2 113
omatthews 8:5da71ae16115 114 while (time < end_time)
omatthews 7:59ece353eea2 115 {
omatthews 8:5da71ae16115 116 Set_R_ref(R_start + ramp_rate * (time - start_time));
omatthews 7:59ece353eea2 117 hold(1);
omatthews 8:5da71ae16115 118 time = timer.read_ms();
omatthews 7:59ece353eea2 119 }
omatthews 8:5da71ae16115 120
omatthews 7:59ece353eea2 121 }
omatthews 7:59ece353eea2 122
omatthews 18:f5d26d3d532f 123 void Heater::ramp_T(const int ramp_time, const float T_final, const float T_start)
omatthews 7:59ece353eea2 124 {
omatthews 18:f5d26d3d532f 125 //Ramps the heater from T_start to T_final for the given hold time
omatthews 18:f5d26d3d532f 126 // in: int hold_time - is the time in ms to hold the reference
omatthews 18:f5d26d3d532f 127 // float T_final - is the final T_ref value
omatthews 18:f5d26d3d532f 128 // float T_start - is the initial T_ref value
omatthews 7:59ece353eea2 129 ramp_R(ramp_time, T_to_R(T_final), T_to_R(T_start));
omatthews 7:59ece353eea2 130 }
omatthews 18:f5d26d3d532f 131
omatthews 18:f5d26d3d532f 132
omatthews 18:f5d26d3d532f 133
omatthews 7:59ece353eea2 134 void Heater::Set_R_ref(float R) {R_ref = R;}
omatthews 7:59ece353eea2 135 void Heater::Set_T_ref(float T_ref) {R_ref = T_to_R(T_ref);}
omatthews 16:cd837b230b09 136 void Heater::Set_D(float D) {drive->write(D);}
omatthews 0:4e33cc8171f4 137
omatthews 18:f5d26d3d532f 138 int Heater::Get_i() const {return curr;}
omatthews 18:f5d26d3d532f 139 int Heater::Get_v() const {return v;}
omatthews 2:7f15386fcc90 140
omatthews 18:f5d26d3d532f 141 float Heater::Get_R() const {return R;}
omatthews 18:f5d26d3d532f 142 float Heater::Get_T() const {return R_to_T(R);}
omatthews 0:4e33cc8171f4 143
omatthews 16:cd837b230b09 144 void Heater::turn_on () {*drive = 1;}
omatthews 1:4435d407d827 145
omatthews 16:cd837b230b09 146 void Heater::turn_off () {*drive = 0;}