dc-sensor/firmware/main/src/functions.c

#include "functions.h"
#include "freertos/FreeRTOS.h"

static const char * TAG = "functions.c";

void split_float(float num, int *int_part, float *dec_part) {
    // Extract the integer part
    *int_part = (float)((int)num);
    
    // Calculate the fractional part by subtracting the integer part from the original number
    *dec_part = num - *int_part;
}

// Helper function to reverse a string
static void reverse(char* str, int len) {
    int i = 0, j = len - 1;
    while (i < j) {
        char temp = str[i];
        str[i] = str[j];
        str[j] = temp;
        i++;
        j--;
    }
}

// Helper function to convert an integer to a string
static int intToStr(int x, char str[], int d) {
    int i = 0;
    while (x) {
        str[i++] = (x % 10) + '0';
        x = x / 10;
    }

    // If the number of digits required is more, then add 0s at the beginning
    while (i < d)
        str[i++] = '0';

    reverse(str, i);
    str[i] = '\0';
    return i;
}

char* floatToString(float num) {
    // Allocate memory for the string
    char* str = (char*)malloc(50 * sizeof(char));
    if (str == NULL) {
        // If memory allocation fails, return NULL
        return NULL;
    }

    // Handle integer part
    int intPart = (int)num;
    int i = intToStr(intPart, str, 0);

    // Handle fractional part
    float fractionalPart = num - (float)intPart;
    if (fractionalPart < 0) {
        fractionalPart = -fractionalPart;
    }

    if (fractionalPart != 0) {
        str[i++] = '.'; // Add decimal point

        // Consider precision up to 6 digits after the decimal point
        for (int j = 0; j < 6; j++) {
            fractionalPart = fractionalPart * 10;
            int fracIntPart = (int)fractionalPart;
            str[i++] = fracIntPart + '0';
            fractionalPart = fractionalPart - fracIntPart;
        }
    }

    str[i] = '\0'; // Null-terminate the string

    return str;
}

// Function to convert an integer to a string
char* intToString(int num)
{
    // Allocate memory for the string
    char* str = (char*)malloc(50 * sizeof(char));

    int i = 0;
    // Save the sign of the number
    int sign = num;

    // If the number is negative, make it positive
    if (num < 0) {
        num = -num;
    }

    // Extract digits from the number and add them to the
    // string
    do {
        // Convert integer digit to character
        str[i++] = num % 10 + '0';
    } while ((num /= 10) > 0);

    // If the number was negative, add a minus sign to the
    // string
    if (sign < 0) {
        str[i++] = '-';
    }

    // Null-terminate the string
    str[i] = '\0';

    // Reverse the string to get the correct order
    for (int j = 0, k = i - 1; j < k; j++, k--) {
        char temp = str[j];
        str[j] = str[k];
        str[k] = temp;
    }

    return str;
}