File content as of revision 1:4435d407d827:

/*------------------------------------------------------------------------------
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 R_set)
    :R_set(R_set),i_port(i_port),v_port(v_port),drive(drive){}


void Heater::read_R()
{
    //Reads R and then resets the drive back to its previous value
    int i = 0;
    int drive_prev = drive;
    drive = 1;
    wait_us(10);
    adc.start_conversion(ALL_CH);
    while(adc_busy == 1)
        {
            wait_us(1);
            i++;
        }
    adc.read_channels();
            
    drive = drive_prev;
    //pc.printf("conversion took %d us\n", i );
    i=0;
    
    
    curr = adc.read_channel_result(i_port)/scale_factors[i_port];
    v = adc.read_channel_result(v_port)/scale_factors[v_port];
    if (curr != 0) R = v/curr;
}

void Heater::hold(int hold_time)
{
    int end_time = timer.read_ms() + hold_time;
    pc.printf("end time is %d \n",end_time);
    float R_avg = 0;
    while (timer.read_ms() < end_time)
    {
        drive = 1;
        wait_us(MEAS_DELAY);
        read_R();
        R_avg = ((N_ROLL_AVG-1)*R_avg + R)/N_ROLL_AVG;
        if (R_avg > R_set)
        {
            drive = 0;
            wait_us(2*MEAS_DELAY);
        }

    }
}


void Heater::Set_R_set(float R) {R_set = R;}

float Heater::Get_R() {return R;}

void Heater::turn_on () {drive = 1;}

void Heater::turn_off () {drive = 0;}