README.md
FastCRC

Fast CRC Arduino library 
Up to 30 times faster than crc16.h (_avr_libc)


uses the on-chip hardware for Teensy 3.0 / 3.1 / 3.2 / 3.5 / 3.6
uses fast table-algorithms for other chips


List of supported CRC calculations:

7 BIT:

CRC7
 (poly=0x09 init=0x00 refin=false refout=false xorout=0x00 check=0x75)
 MultiMediaCard interface

8 BIT:

SMBUS
 (poly=0x07 init=0x00 refin=false refout=false xorout=0x00 check=0xf4)

MAXIM
 (poly=0x31 init=0x00 refin=true refout=true xorout=0x00  check=0xa1)

16 BIT:

KERMIT (Alias CRC-16/CCITT, CRC-16/CCITT-TRUE, CRC-CCITT)
 (poly=0x1021 init=0x0000 refin=true refout=true xorout=0x0000 check=0x2189
  Attention: sometimes you'll find byteswapped presentation of result in other implementations)

CCITT-FALSE
 (poly=0x1021 init=0xffff refin=false refout=false xorout=0x0000 check=0x29b1)

MCRF4XX
 (poly=0x1021 init=0xffff refin=true refout=true xorout=0x0000 check=0x6f91)

MODBUS
 (poly=0x8005 init=0xffff refin=true refout=true xorout=0x0000 check=0x4b37)

XMODEM (Alias ZMODEM, CRC-16/ACORN)
 (poly=0x1021 init=0x0000 refin=false refout=false xorout=0x0000 check=0x31c3)

X25 (Alias CRC-16/IBM-SDLC, CRC-16/ISO-HDLC, CRC-B)
 (poly=0x1021 init=0xffff refin=true refout=true xorout=0xffff check=0x906e)

32 BIT:

CRC32, CRC-32/ADCCP, PKZIP, ETHERNET, 802.3
  (poly=0x04c11db7 init=0xffffffff refin=true refout=true xorout=0xffffffff check=0xcbf43926)

CKSUM, CRC-32/POSIX
  (poly=0x04c11db7 init=0x00000000 refin=false refout=false xorout=0xffffffff check=0x765e7680)