十进制转BCD_10进制转bcd指定长度byte数组-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_44815745/article/details/145268877

十进制转BCD

// @brief double 转换成BCD
// @param buffer
// @param fData 数据
// @param nb_byte 总长度
// @param nb_dec 小数点后位数
uint8_t DecToBcd(uint8_t *buffer, double fData, uint8_t nb_byte, uint8_t nb_dec)
{

    char tmp[32] = {0};
    char  *point = NULL;
    if(nb_byte<nb_dec  || buffer == NULL)
    	return 0;
    // 保留 nb_dec 位小数并将浮点数转换为字符串
    snprintf(tmp, sizeof(tmp), "%.*f", nb_dec, fData);
    uint8_t len = strlen(tmp);
    // 去除小数点
    point = strstr(tmp, ".");
    if(point)
        memcpy(point, point + 1, &tmp[len] - point);
    len = strlen(tmp);
    if(len > nb_byte) {
        strcpy(tmp, &tmp[len - nb_byte]);  /// 保留相应位数
    } else if(len < nb_byte){
        strcpy(&tmp[nb_byte - len], tmp);  // 补 0
        memset(tmp, '0', nb_byte - len);
    }
    len = nb_byte;
    // 奇数 前面补 0
    if (len % 2) {
        strcpy(&tmp[1], tmp);
        tmp[0] = '0';
        len += 1;
    }

    // 填充 buffer
    uint8_t index = 0;
    for (uint8_t i = 0; i < len; i += 2) {
        uint8_t digit1 = tmp[i] - '0';
        uint8_t digit2 = (i + 1 < len)? (tmp[i + 1] - '0') : 0;
        buffer[index++] = (digit1 << 4) | digit2;
    }
    return index;
}
int main() {
    uint8_t buffer[10]={0};
    double value = 123.45;
    DecToBcd(buffer, value, 7, 2);
    for (int i = 0; i < 7; i++) {
        printf("%02X ", buffer[i]);
    }
    printf("\n");
    return 0;
}