libscrc

libscrc is a library for calculating CRC4 CRC5 CRC6 CRC7 CRC8 CRC16 CRC32 CRC64.

CRCx	CRC8	CRC16	CRC32	CRC64
CRC4-ITU	Intel	Modbus	FSC	ISO
CRC5-ITU	BCC	IBM	CRC32	ECMA182
CRC5-EPC	LRC	XModem	MPEG2
CRC5-USB	MAXIM8	CCITT
CRC6-ITU	ROHC	Kermit
CRC7-MMC	ITU8	Sick
	CRC8	DNP
		X25
		USB
		MAXIM16
		DECT

Installation

Compile and install the library:
```
pip3 install libscrc
```
or:
```
python setup.py build
python setup.py install
```
You will need the administrative privileges to execute the last command.

Cross compile and install the library:

# vim setup.cfg
universal=1
plat-name=linux_armv7l

export CROSS_COMPILE=arm-linux-gnueabihf-
export CC='${CROSS_COMPILE}gcc -pthread'
export LDSHARED='${CROSS_COMPILE}gcc -shared'
export CFLAGS='-I/usr/include/python3.5m -I/usr/include/'

python3 setup.py build
# gcc version 6.2.1 20161016 (Linaro GCC 6.2-2016.11)

After installation you can run unit tests to make sure that the library works fine. Execute:
```
python -m libscrc.testmodbus
python -m libscrc.testcrc64
```

Usage

In Python 3:

import libscrc
crc16 = libscrc.modbus(b'1234')  # Calculate ASCII of modbus
crc16 = libscrc.modbus(b'\x01\x02')  # Calculate HEX of modbus

You can also calculate CRC gradually:

import libscrc
crc16 = libscrc.xmodem(b'1234')
crc16 = libscrc.xmodem(b'5678', crc16)

Example

CRCx:

crc4 = libscrc.itu4(b'1234')
crc5 = libscrc.itu5(b'1234')
crc5 = libscrc.epc(b'1234')
crc5 = libscrc.usb5(b'1234')
crc6 = libscrc.itu6(b'1234')
crc7 = libscrc.mmc(b'1234')

CRC8:

crc8 = libscrc.intel(b'1234')
crc8 = libscrc.bcc(b'1234')
crc8 = libscrc.lrc(b'1234')
crc8 = libscrc.maxim8(b'1234')
crc8 = libscrc.rohc(b'1234')
crc8 = libscrc.itu8(b'1234')
crc8 = libscrc.crc8(b'1234')

CRC16:

crc16 = libscrc.ibm(b'1234')            # poly=0xA001 (default Reversed)
crc16 = libscrc.ibm(b'1234', 0x8005)    # poly=0x8005 (Normal)
crc16 = libscrc.modbus(b'1234')
crc16 = libscrc.xmodem(b'1234')
crc16 = libscrc.ccitt(b'1234')
crc16 = libscrc.ccitt_false(b'1234')
crc16 = libscrc.kermit(b'1234')
crc16 = libscrc.sick(b'1234')
crc16 = libscrc.dnp(b'1234')
crc16 = libscrc.x25(b'1234')
crc16 = libscrc.usb16(b'1234')
crc16 = libscrc.maxim16(b'1234')
crc16 = libscrc.dect(b'1234')           # poly=0x0589 (Cordless Telephones)

CRC32:

crc32 = libscrc.fsc(b'1234')            # Ethernet frame sequence (FSC)
crc32 = libscrc.mpeg2(b'1234')          # MPEG2
crc32 = libscrc.crc32(b'1234')          # WinRAR, File

CRC64:

crc64 = libscrc.iso(b'1234')
crc64 = libscrc.ecma182(b'1234')

V0.1.5 (2017-09-22)

New CRC4-ITU Poly = 0x03 Initial = 0x00 Xorout=0x00 Refin=True Refout=True
New CRC5-ITU Poly = 0x15 Initial = 0x00 Xorout=0x00 Refin=True Refout=True
New CRC5-EPC Poly = 0x09 Initial = 0x09 Xorout=0x00 Refin=False Refout=False
New CRC5-USB Poly = 0x05 Initial = 0x1F Xorout=0x1F Refin=True Refout=True
New CRC6-ITU Poly = 0x03 Initial = 0x00 Xorout=0x00 Refin=True Refout=True
New CRC7-MMC Poly = 0x09 Initial = 0x00 Xorout=0x00 Refin=False Refout=False

V0.1.4 (2017-09-21)

New CRC8-MAXIM8 Poly = 0x31 Initial = 0x00 Xorout=0x00 Refin=True Refout=True
New CRC8-ROHC Poly = 0x07 Initial = 0xFF Xorout=0x00 Refin=True Refout=True
New CRC8-ITU Poly = 0x07 Initial = 0x00 Xorout=0x55 Refin=False Refout=False
New CRC8-CRC8 Poly = 0x07 Initial = 0x00 Xorout=0x00 Refin=False Refout=False

V0.1.3 (2017-09-19)

New CRC16-X25
New CRC16-USB
New CRC16-MAXIM16
New CRC16-CCITT_FALSE
New CRC16-DECT

Bugfixes

Calculate CRC16-IBM of poly = 0x8005 is ERROR.

V0.1.2 (2017-08-22)

Platform Support

Win32
Linux_x86_64
MacOSX_10_6_intel
ARMv7 (Toradex Ixora iMX6 Linux-4.1.41)