convert float to char, make transmission easier.

float_to_char.c

#include <stdio.h>
/*
 * two ways of converting float to string or char
 *
 * */
typedef union {
    float f;
    char c[4];
} my_union_t;

// 1.
// using union to define new data type
//
// advantage here is the data will be exactly same between in original format, no need transition
//
void fun1() {
    my_union_t u1;
    u1.f = 3.9;
    printf("float: %f\n char: %s \n", u1.f, u1.c);
}

// 2.
// using sprintf
//
// Advantage here is it will looked clearly for human
//
void fun2() {
    float v_f = 4.8;
    char c[20];
    sprintf(c, "%f", v_f);
    printf("float: %f\n char: %s \n", v_f, c);
}

int main() {
    fun1();
    fun2();
    return 0;
}