CRC32校验代码，ardiuno框架下ESP32开发

原创已于 2025-06-15 16:02:27 修改 · 468 阅读

10 ·

CC 4.0 BY-SA版权

文章标签：

#mcu #物联网 #单片机 #iot #CRC #CRC32 #CRC校验

于 2025-06-15 15:58:29 首次发布

本人在做一个ESP32项目，使用VScode开发，其中蓝牙数据需要用到crc32校验。

CRC校验的定义

CRC（Cyclic Redundancy Check，循环冗余校验）是一种用于检测数据传输或存储过程中是否出现错误的校验方法。其核心思想是通过数学运算生成一个固定长度的校验码（CRC值），附加在原始数据后，接收方通过相同的算法验证数据的完整性。

CRC校验的原理

CRC基于多项式除法，将数据视为二进制系数的大数，与预定的生成多项式进行模2除法运算，得到的余数即为校验码。关键要素包括：

生成多项式：预先设定的二进制数，如CRC-16的0x8005，不同标准对应不同多项式。
初始值：计算前寄存器的初始状态，通常为全0或全1。
输入输出处理：可能涉及数据反转、结果异或等后处理步骤。

数学公式表示为：
[ M(x) \cdot x^n = Q(x) \cdot G(x) + R(x) ]
其中，( M(x) )为数据多项式，( G(x) )为生成多项式，( R(x) )为余数（即CRC值）。

CRC校验的应用场景

网络通信：如以太网帧（CRC-32）、Wi-Fi数据传输。
存储系统：检测硬盘、SSD等存储介质的读写错误。
文件传输：ZIP、RAR等压缩包校验文件完整性。

CRC校验的特点

高效性：硬件实现简单，计算速度快。
检测能力：可识别单比特错误、突发错误（取决于多项式选择）。
非加密性：仅用于检错，无法纠正错误或保证数据安全性。

常见CRC标准示例

CRC-8：用于简单协议，多项式0x07。
CRC-16：Modbus协议使用0x8005。
CRC-32：以太网、ZIP文件采用0x04C11DB7。

可以使用pycrc生成crc代码。

pycrc 是一个用 Python 编写的免费循环冗余校验（CRC）C 源代码生成器。

CRC 算法可以选择从快速但占用空间的实现到较慢但较小的版本，特别适合嵌入式应用。CRC 参数可以自由选择，一些著名的 CRC 模型可以通过名称而不是参数来参考。

您可以直接使用 pycrc，除了 Python 2.6 或更高版本外，无需其他依赖。无需安装或额外的模块。支持 Python 3。

crc.cpp

/**
 * \file
 * Functions and types for CRC checks.
 *
 * Generated on Tue Jan  7 07:33:25 2020
 * by pycrc v0.9.2, https://pycrc.org
 * using the configuration:
 *  - Width         = 32
 *  - Poly          = 0x04c11db7
 *  - XorIn         = 0xffffffff
 *  - ReflectIn     = True
 *  - XorOut        = 0xffffffff
 *  - ReflectOut    = True
 *  - Algorithm     = table-driven
 */
#include "crc.h"     /* include the header file generated with pycrc */
#include <stdlib.h>
#include <stdint.h>



/**
 * Static table used for the table_driven implementation.
 */
static const crc_t crc_table[256] = {
    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
    0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
    0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
    0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
    0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
    0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
    0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
    0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
    0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
    0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
    0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
    0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
    0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
    0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
    0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
    0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
    0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
    0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
    0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
    0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
    0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
    0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};


crc_t crc_update(crc_t crc, const void *data, size_t data_len)
{
    const unsigned char *d = (const unsigned char *)data;
    unsigned int tbl_idx;

    while (data_len--) {
        tbl_idx = (crc ^ *d) & 0xff;
        crc = (crc_table[tbl_idx] ^ (crc >> 8)) & 0xffffffff;
        d++;
    }
    return crc & 0xffffffff;
}

crc.h

/**
 * \file
 * Functions and types for CRC checks.
 *
 * Generated on Tue Jan  7 07:33:20 2020
 * by pycrc v0.9.2, https://pycrc.org
 * using the configuration:
 *  - Width         = 32
 *  - Poly          = 0x04c11db7
 *  - XorIn         = 0xffffffff
 *  - ReflectIn     = True
 *  - XorOut        = 0xffffffff
 *  - ReflectOut    = True
 *  - Algorithm     = table-driven
 *
 * This file defines the functions crc_init(), crc_update() and crc_finalize().
 *
 * The crc_init() function returns the initial \c crc value and must be called
 * before the first call to crc_update().
 * Similarly, the crc_finalize() function must be called after the last call
 * to crc_update(), before the \c crc is being used.
 * is being used.
 *
 * The crc_update() function can be called any number of times (including zero
 * times) in between the crc_init() and crc_finalize() calls.
 *
 * This pseudo-code shows an example usage of the API:
 * \code{.c}
 * crc_t crc;
 * unsigned char data[MAX_DATA_LEN];
 * size_t data_len;
 *
 * crc = crc_init();
 * while ((data_len = read_data(data, MAX_DATA_LEN)) > 0) {
 *     crc = crc_update(crc, data, data_len);
 * }
 * crc = crc_finalize(crc);
 * \endcode
 */
#ifndef CRC_H
#define CRC_H

#include <stdlib.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif


/**
 * The definition of the used algorithm.
 *
 * This is not used anywhere in the generated code, but it may be used by the
 * application code to call algorithm-specific code, if desired.
 */
#define CRC_ALGO_TABLE_DRIVEN 1


/**
 * The type of the CRC values.
 *
 * This type must be big enough to contain at least 32 bits.
 */
typedef uint32_t crc_t;


/**
 * Calculate the initial crc value.
 *
 * \return     The initial crc value.
 */
static inline crc_t crc_init(void)
{
    return 0xffffffff;
}


/**
 * Update the crc value with new data.
 *
 * \param[in] crc      The current crc value.
 * \param[in] data     Pointer to a buffer of \a data_len bytes.
 * \param[in] data_len Number of bytes in the \a data buffer.
 * \return             The updated crc value.
 */
crc_t crc_update(crc_t crc, const void *data, size_t data_len);


/**
 * Calculate the final crc value.
 *
 * \param[in] crc  The current crc value.
 * \return     The final crc value.
 */
static inline crc_t crc_finalize(crc_t crc)
{
    return crc ^ 0xffffffff;
}


#ifdef __cplusplus
}           /* closing brace for extern "C" */
#endif

#endif      /* CRC_H */

Arduino_CRC32.cpp

/*
  Copyright (c) 2020 Arduino.  All rights reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

/**************************************************************************************
 * INCLUDE
 **************************************************************************************/

#include "Arduino_CRC32.h"

/**************************************************************************************
 * PUBLIC MEMBER FUNCTIONS
 **************************************************************************************/

void Arduino_CRC32::init(uint32_t start)
{
  crc32_start = start;
}

uint32_t Arduino_CRC32::calc(uint8_t const data[], uint32_t const len)
{
  crc_t crc32;
  crc32 = crc_update(crc32_start, data, len);
  crc32 = crc_finalize(crc32);
  return crc32;
}

Arduino_CRC32.h

/*
  Copyright (c) 2020 Arduino.  All rights reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef ARDUINO_CRC32_H_
#define ARDUINO_CRC32_H_

/**************************************************************************************
 * INCLUDE
 **************************************************************************************/

#include <stdint.h>
#include "crc.h"
/**************************************************************************************
 * CLASS DECLARATION
 **************************************************************************************/

class Arduino_CRC32
{

public:
  crc_t crc32_start;
  void init(uint32_t start);
  uint32_t calc(uint8_t const data[], uint32_t const len);

};

#endif /* ARDUINO_CRC32_H_ */