Heater files
Dependents: LEX-Demo-Firmware-Logging LEX-Demo-Firmware-Logging
Heater.cpp
- Committer:
- omatthews
- Date:
- 2019-07-22
- Revision:
- 10:0e16d8430d66
- Parent:
- 8:5da71ae16115
- Child:
- 11:785a0329f802
File content as of revision 10:0e16d8430d66:
/*------------------------------------------------------------------------------ Library code file for interface to Heater Date: 16/07/2018 ------------------------------------------------------------------------------*/ #include "mbed.h" #include "MODSERIAL.h" #include "Heater.h" #include "ADS8568_ADC.h" extern ADS8568_ADC adc; extern float scale_factors[8]; extern Timer timer; extern DigitalIn adc_busy; extern MODSERIAL pc; Heater::Heater(int i_port, int v_port, DigitalOut drive, float corr_grad, float corr_int, float R_ref) :R_ref(R_ref),i_port(i_port),v_port(v_port),drive(drive),corr_grad(corr_grad),corr_int(corr_int) {} float Heater::R_to_T(float R) {return R*corr_grad + corr_int;} float Heater::T_to_R(float T) {return (T - corr_int)/corr_grad;} void Heater::read() { //Reads R and then resets the drive back to its previous value timer.reset(); int i = 0; int drive_prev = drive; //Store previous value of drive drive = 1; wait_us(MEAS_DELAY); //Wait for ADC to settle adc.start_conversion(ALL_CH); while(adc_busy == 1) { wait_us(1); i++; } drive = drive_prev; adc.read_channels(); //pc.printf("conversion took %d us\n", i ); //i=0; curr = adc.read_channel_result(i_port); v = adc.read_channel_result(v_port); if (v<0) {pc.printf("v is %d",v);} //if (curr > 0) {R = (float)v/curr;} //Avoid dividing by 0 R = (float)v/curr; } void Heater::hold(int hold_time) { //Holds the heater at R_ref for the given hold time // in: int hold_time - is the time in ms to hold the reference int end_time = timer.read_ms() + hold_time; while (timer.read_ms() < end_time) { read(); if (R > R_ref) { drive = 0; wait_ms(10); //Minimum duty cycle of 10% } else { drive = 1; } } } void Heater::ramp_R(int ramp_time, float R_final, float R_start) { int time = timer.read_ms(); int start_time = time; int end_time = start_time + ramp_time; float ramp_rate = (R_final - R_start)/ramp_time; while (time < end_time) { Set_R_ref(R_start + ramp_rate * (time - start_time)); hold(1); time = timer.read_ms(); } } void Heater::ramp_T(int ramp_time, float T_final, float T_start) { ramp_R(ramp_time, T_to_R(T_final), T_to_R(T_start)); } void Heater::Set_R_ref(float R) {R_ref = R;} void Heater::Set_T_ref(float T_ref) {R_ref = T_to_R(T_ref);} int Heater::Get_i() {return curr;} int Heater::Get_v() {return v;} float Heater::Get_R() {return R;} float Heater::Get_T() {return R_to_T(R);} void Heater::turn_on () {drive = 1;} void Heater::turn_off () {drive = 0;}