#include <stdio.h>
#include <stdint.h>

#define NUM_TO_ASCII(num) ((num) + '0')

void dev_serial_number_to_string(char *s, uint8_t *sn, uint8_t len)
{
    uint8_t interval = 0; // 间隔x位插入'-'
    uint8_t count = 0;
    for (uint8_t i = 0; i < len; i++)
    {
        s[count] = NUM_TO_ASCII(*(sn + i));
        count++;
        if (interval != 0)
        {
            if ((i + 1) % interval == 0 && count < count + len / interval)
            {
                s[count] = '-';
                count++;
            }
        }
    }

    if (interval != 0)
    {
        s[len + len / interval - 1] = '\0'; // 添加字符串结束符
    }
    else
    {
        s[len] = '\0'; // 添加字符串结束符
    }
}

int main()
{
    uint8_t sn[16] = {0}; // 16个0
    char s[19];           // 16 digits + 3 dashes + 1 null terminator
    dev_serial_number_to_string(s, sn, 16);

    printf("Formatted serial number: %s\n", s);

    return 0;
}