HBLink/crc.py
Cort Buffington 9fefedc2fd fix typos
2016-11-23 15:07:10 -06:00

56 lines
1.9 KiB
Python
Executable File

#!/usr/bin/env python
#
###############################################################################
# Copyright (C) 2016 Cortney T. Buffington, N0MJS <n0mjs@me.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
###############################################################################
from __future__ import print_function
from bitarray import bitarray
# Does anybody read this stuff? There's a PEP somewhere that says I should do this.
__author__ = 'Cortney T. Buffington, N0MJS'
__copyright__ = 'Copyright (c) 2016 Cortney T. Buffington, N0MJS and the K0USY Group'
__credits__ = 'Jonathan Naylor, G4KLX'
__license__ = 'GNU GPLv3'
__maintainer__ = 'Cort Buffington, N0MJS'
__email__ = 'n0mjs@me.com'
def csum5(_data):
_data = bytearray(_data)
accum = 0
assert len(_data) == 9, 'csum5 expected 9 bytes of data and got something else'
for i in xrange(9):
accum += _data[i]
accum = chr(accum % 31)
csum = bitarray()
csum.frombytes(accum)
del csum[0:3]
return csum
if __name__ == '__main__':
from binascii import b2a_hex as h
message = '\x00\x10\x20\x00\x0c\x30\x2f\x9b\xe5'
result = csum5(message)
print(result, type(result))