CRC校驗計算

CRC校驗計算

循環冗餘校驗（Cyclic Redundancy Check， CRC）是一種根據網絡數據包或計算機文件等數據產生簡短固定位數校驗碼的一種信道編碼技術，主要用來檢測或校驗數據傳輸或者保存後可能出現的錯誤。它是利用除法及餘數的原理來作錯誤偵測的

PS 在開發微信小程序項目中時，對接藍牙BLE協議遇到。如理解有誤，歡迎指點

CRC（循環冗餘校驗）在線計算

驗算方法

CRC-8 (X8+X2+X+1)

check_crc8(buffer) {
    var CHECKSUM_TABLE = [
        0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b,
        0x12, 0x15, 0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a,
        0x2d, 0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
        0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d, 0xe0,
        0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5, 0xd8, 0xdf,
        0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd, 0x90, 0x97, 0x9e,
        0x99, 0x8c, 0x8b, 0x82, 0x85, 0xa8, 0xaf, 0xa6, 0xa1,
        0xb4, 0xb3, 0xba, 0xbd, 0xc7, 0xc0, 0xc9, 0xce, 0xdb,
        0xdc, 0xd5, 0xd2, 0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4,
        0xed, 0xea, 0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5,
        0xa2, 0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
        0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32, 0x1f,
        0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a, 0x57, 0x50,
        0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42, 0x6f, 0x68, 0x61,
        0x66, 0x73, 0x74, 0x7d, 0x7a, 0x89, 0x8e, 0x87, 0x80,
        0x95, 0x92, 0x9b, 0x9c, 0xb1, 0xb6, 0xbf, 0xb8, 0xad,
        0xaa, 0xa3, 0xa4, 0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2,
        0xeb, 0xec, 0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3,
        0xd4, 0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
        0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44, 0x19,
        0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c, 0x21, 0x26,
        0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34, 0x4e, 0x49, 0x40,
        0x47, 0x52, 0x55, 0x5c, 0x5b, 0x76, 0x71, 0x78, 0x7f,
        0x6a, 0x6d, 0x64, 0x63, 0x3e, 0x39, 0x30, 0x37, 0x22,
        0x25, 0x2c, 0x2b, 0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d,
        0x14, 0x13, 0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc,
        0xbb, 0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
        0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb, 0xe6,
        0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
    ]
    let crc = new Uint8Array(1);
    crc = 0;
    for (let i = 0; i < buffer.length; i++) {
        crc = CHECKSUM_TABLE[(crc ^ (buffer[i] & 0xFF)) & 0xFF];
    }
    
    return (crc & 0xff);
},

使用

// 傳入需計算字節
let testHex = [0x6a, 0x00, 0x5f, 0x3a, 0x00, 0x01, 0xd5, 0x42];
let getCheckCRC = that.check_crc8(testHex);
console.log("得到校驗CRC爲====》", getCheckCRC); //166

ios中驗算方法

這是ios中的驗算方法，測試ok的

/*
*函數：CRC8的驗算公式
*參數：數組，長度
*返回：crc校驗
*/
unsigned char CRC8(unsigned char *ptr,unsigned char len)
{
 
    unsigned char crc;
    unsigned char i;
    crc = 0;
    while(len--)
    {
       crc ^= *ptr++;
       for(i = 0;i < 8;i++)
       {
           if(crc & 0x80)
           {
               crc = (crc << 1) ^ 0x07;
           }
           else crc <<= 1;
       }
    }
    return crc;
}

感謝大神文章