mikrokontrollersystemer-prosjekt/prosjekt.X/main.c

/* 
 * File:   main.c
 * Author: Sebastian H. Gabrielli
 *
 * Created on March 6, 2024, 12:34 PM
 */

#define F_CPU 4E6

#include <stdio.h>
#include <stdlib.h>
#include "uart.h"
#include <util/delay.h>

#define R_t0 10000
#define T_0 298.15
#define B 3950
#define R_1 1000

float R_therm;
float V_1;
float ln; 
float T_therm;
float V_therm;

// Takes inn messured value 
// Calculates the temperature in celcius
// Returns the themperature
float calculate_thermistor_temp(float readValue){
    uint8_t V_tot = 5;
    // Calculate Voltage over thermistor
    V_therm = (V_tot/1024)*readValue;
    
    // 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;
}


int main() {
    init_uart((uint16_t)9600);
    stdout = &USART_stream;

    while (1) {
        printf("Hello, world!\n");
        _delay_ms(500);
    }
}