mikrokontrollersystemer-prosjekt/prosjekt.X/thermistor-temp.c

#include "themistor-temp.h"

float calculate_thermistor_temp(float thermistor_voltage){
    float R_therm;
    float V_1;
    float ln; 
    float T_therm;
    float V_therm;
    uint8_t V_tot = 5;
    // Calculate Voltage over thermistor
    V_therm = (V_tot/1024)*thermistor_voltage;
    
    // Voltage accross R_1
    V_1 = V_tot - V_therm; 
    
    // Calculate Thermistor resistanse
    R_therm = (V_therm)/ (V_1 / R_1);
    
    // Steinhart-Harts formula
    ln = log(R_therm/R_t0);
    T_therm = (1/ ((ln/B) + (1/T_0)));
    
    // Temperatur in celcius
    T_therm -= 273.15;
    
    return T_therm;
}

// returns error message if the messured thermistor temp is higher than
// Choosen max_temp
bool voltage_threshold_bool(float thermistor_temp, uint8_t max_temp){
    // Return true if temp is higher then max value
    if (thermistor_temp >= max_temp){
        return true;
    }
    else {
        return false;
    }
}

//print if the maximum threshold is exceeded. 
void voltage_threshold_exceeded(bool voltage_threshold_bool){
    if (voltage_threshold_bool){
        printf("Error: maximum temperature exceeded");
    } 
}