#include <stdio.h>
#include <stdlib.h>

double readTemp(void) {
//  dummy: should read temperature from ADC
    static double val = 0.0;
    val += 0.5;
    if (val > 20.0)
        val = 0.0;
    return val;
}

void writeSwitch(int i) {
//  dummy: should write to switch
}

double readPres(void) {
//  dummy: should read pressure from ADC
    static double val = 20.0;
    val -= 0.4;
    if (val < 0.0)
        val = 20.0;
    return val;
}

void writeDAC(double d) {
//  dummy: should write to DAC
}

int tempControl(double temp) {
//  dummy: should use better algorithm
    static struct timespec ms100 = {0, 100000000};
    nanosleep(&ms100, NULL);
    return temp > 10.0;
}

double presControl(double pres) {
//  dummy: should use better algorithm
    static struct timespec ms100 = {0, 100000000};
    nanosleep(&ms100, NULL);
    return 10.0 - pres;
}

int main(void) {
    double temp, pres, dac;
    int switch_;
    while (1) {
        temp = readTemp();
        switch_ = tempControl(temp);
        writeSwitch(switch_);
        pres = readPres();
        dac = presControl(pres);
        writeDAC(dac);
        printf("temperature = %4.1lf, pressure = %4.1lf, switch = %d, DAC = %5.1lf\n", temp, pres, switch_, dac);
    }
    return EXIT_SUCCESS;
}