Ollie Matthews / Heater

Heater for threaded program

Dependents:   LEX_Threaded_Programming

Heater.cpp@8:5da71ae16115, 2019-07-19 (annotated)

Committer:
omatthews
Date:
Fri Jul 19 10:31:38 2019 +0000
Revision:
8:5da71ae16115
Parent:
7:59ece353eea2
Child:
9:405e86b02d63
Child:
10:0e16d8430d66
Overshoot;

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 float scale_factors[8];
omatthews 0:4e33cc8171f4 14 extern Timer timer;
omatthews 1:4435d407d827 15 extern DigitalIn adc_busy;
omatthews 1:4435d407d827 16 extern MODSERIAL pc;
omatthews 1:4435d407d827 17
omatthews 0:4e33cc8171f4 18
omatthews 0:4e33cc8171f4 19
omatthews 8:5da71ae16115 20 Heater::Heater(int i_port, int v_port, DigitalOut drive, float corr_grad, float corr_int, float R_ref)
omatthews 8:5da71ae16115 21 :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 22
omatthews 7:59ece353eea2 23 float Heater::R_to_T(float R) {return R*corr_grad + corr_int;}
omatthews 7:59ece353eea2 24 float Heater::T_to_R(float T) {return (T - corr_int)/corr_grad;}
omatthews 0:4e33cc8171f4 25
omatthews 0:4e33cc8171f4 26
omatthews 2:7f15386fcc90 27 void Heater::read()
omatthews 0:4e33cc8171f4 28 {
omatthews 1:4435d407d827 29 //Reads R and then resets the drive back to its previous value
omatthews 7:59ece353eea2 30
omatthews 1:4435d407d827 31 int i = 0;
omatthews 8:5da71ae16115 32 //int drive_prev = drive; //Store previous value of drive
omatthews 8:5da71ae16115 33 drive = 1;
omatthews 7:59ece353eea2 34 wait_us(MEAS_DELAY); //Wait for ADC to settle
omatthews 1:4435d407d827 35 adc.start_conversion(ALL_CH);
omatthews 1:4435d407d827 36 while(adc_busy == 1)
omatthews 1:4435d407d827 37 {
omatthews 1:4435d407d827 38 wait_us(1);
omatthews 1:4435d407d827 39 i++;
omatthews 1:4435d407d827 40 }
omatthews 8:5da71ae16115 41 //drive = drive_prev;
omatthews 0:4e33cc8171f4 42 adc.read_channels();
omatthews 8:5da71ae16115 43
omatthews 8:5da71ae16115 44 //pc.printf("conversion took %d us\n", i );
omatthews 7:59ece353eea2 45 //i=0;
omatthews 1:4435d407d827 46
omatthews 7:59ece353eea2 47 curr = adc.read_channel_result(i_port);
omatthews 7:59ece353eea2 48 v = adc.read_channel_result(v_port);
omatthews 7:59ece353eea2 49 if (v<0) {pc.printf("v is %d",v);}
omatthews 8:5da71ae16115 50 //if (curr > 0) {R = (float)v/curr;} //Avoid dividing by 0
omatthews 8:5da71ae16115 51 R = (float)v/curr;
omatthews 0:4e33cc8171f4 52 }
omatthews 0:4e33cc8171f4 53
omatthews 2:7f15386fcc90 54
omatthews 2:7f15386fcc90 55
omatthews 2:7f15386fcc90 56
omatthews 0:4e33cc8171f4 57 void Heater::hold(int hold_time)
omatthews 0:4e33cc8171f4 58 {
omatthews 7:59ece353eea2 59 //Holds the heater at R_ref for the given hold time
omatthews 7:59ece353eea2 60 // in: int hold_time - is the time in ms to hold the reference
omatthews 7:59ece353eea2 61
omatthews 0:4e33cc8171f4 62 int end_time = timer.read_ms() + hold_time;
omatthews 1:4435d407d827 63 while (timer.read_ms() < end_time)
omatthews 0:4e33cc8171f4 64 {
omatthews 2:7f15386fcc90 65 read();
omatthews 7:59ece353eea2 66 if (R > R_ref)
omatthews 0:4e33cc8171f4 67 {
omatthews 8:5da71ae16115 68 drive = 0;
omatthews 8:5da71ae16115 69 wait_ms(10); //Minimum duty cycle of 10%
omatthews 0:4e33cc8171f4 70 }
omatthews 8:5da71ae16115 71
omatthews 0:4e33cc8171f4 72 }
omatthews 1:4435d407d827 73 }
omatthews 1:4435d407d827 74
omatthews 0:4e33cc8171f4 75
omatthews 7:59ece353eea2 76 void Heater::ramp_R(int ramp_time, float R_final, float R_start)
omatthews 7:59ece353eea2 77 {
omatthews 8:5da71ae16115 78 int time = timer.read_ms();
omatthews 8:5da71ae16115 79 int start_time = time;
omatthews 7:59ece353eea2 80 int end_time = start_time + ramp_time;
omatthews 7:59ece353eea2 81 float ramp_rate = (R_final - R_start)/ramp_time;
omatthews 7:59ece353eea2 82
omatthews 8:5da71ae16115 83 while (time < end_time)
omatthews 7:59ece353eea2 84 {
omatthews 8:5da71ae16115 85 Set_R_ref(R_start + ramp_rate * (time - start_time));
omatthews 7:59ece353eea2 86 hold(1);
omatthews 8:5da71ae16115 87 time = timer.read_ms();
omatthews 7:59ece353eea2 88 }
omatthews 8:5da71ae16115 89
omatthews 7:59ece353eea2 90 }
omatthews 7:59ece353eea2 91
omatthews 7:59ece353eea2 92 void Heater::ramp_T(int ramp_time, float T_final, float T_start)
omatthews 7:59ece353eea2 93 {
omatthews 7:59ece353eea2 94 ramp_R(ramp_time, T_to_R(T_final), T_to_R(T_start));
omatthews 7:59ece353eea2 95 }
omatthews 7:59ece353eea2 96 void Heater::Set_R_ref(float R) {R_ref = R;}
omatthews 7:59ece353eea2 97 void Heater::Set_T_ref(float T_ref) {R_ref = T_to_R(T_ref);}
omatthews 0:4e33cc8171f4 98
omatthews 2:7f15386fcc90 99 int Heater::Get_i() {return curr;}
omatthews 2:7f15386fcc90 100 int Heater::Get_v() {return v;}
omatthews 2:7f15386fcc90 101
omatthews 0:4e33cc8171f4 102 float Heater::Get_R() {return R;}
omatthews 7:59ece353eea2 103 float Heater::Get_T() {return R_to_T(R);}
omatthews 0:4e33cc8171f4 104
omatthews 8:5da71ae16115 105 void Heater::turn_on () {drive = 1;}
omatthews 1:4435d407d827 106
omatthews 8:5da71ae16115 107 void Heater::turn_off () {drive = 0;}