can't get string conversion strtod in c

Could somebody help me(sorry for the english), Im trying to convert a string to a double but when I can't get it here's my code(thank you, I'll appreciate help so much):

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

#define MAX_LONG 5

char bx[MAX_LONG];
double cali=0;

int main() {
scanf("%c",bx);
cali = strtod(bx,NULL);
printf("%f",cali);
return 0;
}

when I input a value greater than 10 in the output it just print the first number like this:

 input: 23
 output: 2.00000
 input: 564
 output: 5.00000

The scanf() specifier you are using is wrong, unless you specify a number of characters, but then the array will not be nul terminated, I suggest the following

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

int main() 
{
    char   bx[6]; /* if you want 5 characters, need an array of 6
                   * because a string needs a `nul' terminator byte
                   */
    double cali;
    char  *endptr;

    if (scanf("%5s", bx) != 1)
    {
        fprintf(stderr, "`scanf()' unexpected error.\n");
        return -1;
    }

    cali = strtod(bx, &endptr);
    if (*endptr != '\0')
    {
        fprintf(stderr, "cannot convert, `%s' to `double'\n", bx);
        return -1;
    }        
    printf("%f\n", cali);
    return 0;
}