背景：在做一个第功耗蓝牙的我的项目，用到了crc校验、分包发送
CRC-16/XMODEM 校验
都是传入16进制的字符串,不便看到 如：'FF2233FF'
/** 将hex转换为 CRC-16/XMODEM 校验 * * 参数长度须要被2整除 * * 第八位在前，高八位在后 */export const crc16xmodem = (datass) => { return CRC_16_XMODEM(Str2Bytes(datass), datass.length / 2)}const Str2Bytes = (str) => { var pos = 0; var len = str.length; if (len % 2 != 0) { return null; } len /= 2; var hexA = new Array(); for (var i = 0; i < len; i++) { var s = str.substr(pos, 2); var v = parseInt(s, 16); hexA.push(v); pos += 2; } return hexA; } function CRC_16_XMODEM(bytes, length) { let crc = 0x0000; let polynomial = 0x1021; for (let index = 0; index < length; index++) { let b = bytes[index]; for (let i = 0; i < 8; i++) { let bit = ((b >> (7 - i) & 1) == 1); let c15 = ((crc >> 15 & 1) == 1); crc <<= 1; if (c15 ^ bit) crc ^= polynomial; } } crc &= 0xffff; // 输入String字样的16进制 let strCrc = crc.toString(16).toLocaleUpperCase(); switch (strCrc.length) { case 1: strCrc = "000" + strCrc; break; case 2: strCrc = "00" + strCrc; break; case 3: strCrc = "0" + strCrc; break; case 4: strCrc = strCrc break; default: break; } strCrc = strCrc[2] + strCrc[3] + strCrc[0] + strCrc[1] return strCrc; }CRC-16/MODBUS 查表法
应用：const crcData = CRC.ToModbusCRC16('FF2233FF')
var CRC = {};CRC._auchCRCHi = [ 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40];CRC._auchCRCLo = [ 0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40];CRC.CRC16 = function (buffer) { var hi = 0xff; var lo = 0xff; for (var i = 0; i < buffer.length; i++) { var idx = hi ^ buffer[i]; hi = (lo ^ CRC._auchCRCHi[idx]); lo = CRC._auchCRCLo[idx]; } return CRC.padLeft((hi << 8 | lo ).toString(16).toUpperCase(), 4, '0');};CRC.isArray = function (arr) { return Object.prototype.toString.call(arr) === '[object Array]';};CRC.ToCRC16 = function (str) { return CRC.CRC16(CRC.isArray(str) ? str : CRC.strToByte(str));};CRC.ToModbusCRC16 = function (str) { return CRC.CRC16(CRC.isArray(str) ? str : CRC.strToHex(str));};CRC.strToByte = function (str) { var tmp = str.split(''), arr = []; for (var i = 0, c = tmp.length; i < c; i++) { var j = encodeURI(tmp[i]); if (j.length == 1) { arr.push(j.charCodeAt()); } else { var b = j.split('%'); for (var m = 1; m < b.length; m++) { arr.push(parseInt('0x' + b[m])); } } } return arr;};CRC.convertChinese = function (str) { var tmp = str.split(''), arr = []; for (var i = 0, c = tmp.length; i < c; i++) { var s = tmp[i].charCodeAt(); if (s <= 0 || s >= 127) { arr.push(s.toString(16)); } else { arr.push(tmp[i]); } } return arr;};CRC.filterChinese = function (str) { var tmp = str.split(''), arr = []; for (var i = 0, c = tmp.length; i < c; i++) { var s = tmp[i].charCodeAt(); if (s > 0 && s < 127) { arr.push(tmp[i]); } } return arr;};CRC.strToHex = function (hex, isFilterChinese) { hex = isFilterChinese ? CRC.filterChinese(hex).join('') : CRC.convertChinese(hex).join(''); //革除所有空格 hex = hex.replace(/\s/g, ""); //若字符个数为奇数，补一个空格 hex += hex.length % 2 != 0 ? " " : ""; var c = hex.length / 2, arr = []; for (var i = 0; i < c; i++) { arr.push(parseInt(hex.substr(i * 2, 2), 16)); } return arr;};CRC.padLeft = function (s, w, pc) { if (pc == undefined) { pc = '0'; } for (var i = 0, c = w - s.length; i < c; i++) { s = pc + s; } return s;};