@serialpilot/crc

Pure-function, table-driven CRC kit. Zero dependencies, zero allocation in the hot path, lookup tables computed once at module load, and no node:* imports — runs unchanged in browsers and Web Serial.

Install

npm install @serialpilot/crc

Use

import {
  crc8,
  crc16Modbus,
  crc16Ccitt,
  crc16Xmodem,
  crc32,
  crc32c,
  CrcStream,
} from '@serialpilot/crc'

const data = new TextEncoder().encode('123456789')

crc16Modbus(data).toString(16) // '4b37'
crc16Ccitt(data).toString(16)  // '29b1'
crc16Xmodem(data).toString(16) // '31c3'
crc32(data).toString(16)       // 'cbf43926'
crc32c(data).toString(16)      // 'e3069283'
crc8(data).toString(16)        // 'f4'  (CRC-8/SMBUS preset)

// Streaming form for inputs you can't hold in one buffer:
const s = new CrcStream('crc32')
for (const chunk of chunks) s.update(chunk)
s.digest()

Presets

| Function | Width | Poly | Init | RefIn | RefOut | XorOut | Check ('123456789') | | ------------ | ----- | ------------ | ---------- | ----- | ------ | ---------- | --------------------- | | crc8 | 8 | 0x07 | 0x00 | false | false | 0x00 | 0xF4 | | crc16Modbus| 16 | 0x8005 | 0xFFFF | true | true | 0x0000 | 0x4B37 | | crc16Ccitt | 16 | 0x1021 | 0xFFFF | false | false | 0x0000 | 0x29B1 | | crc16Xmodem| 16 | 0x1021 | 0x0000 | false | false | 0x0000 | 0x31C3 | | crc32 | 32 | 0x04C11DB7 | 0xFFFFFFFF| true | true | 0xFFFFFFFF| 0xCBF43926 | | crc32c | 32 | 0x1EDC6F41 | 0xFFFFFFFF| true | true | 0xFFFFFFFF| 0xE3069283 |

crc8 accepts an opts object to override the default SMBUS preset ({ poly, init, refIn, refOut, xorOut }).

License

MIT.