Hi, I've put together a basic Wiegand decoder that extracts bit streams from wiegand signals. It stops at the binary level and doesn't extract facility codes/identity numbers etc. This is on the list of possible future decoders at https://sigrok.org/wiki/Protocol_decoders#Possible_candidates_for_future_protocol_decoders
Decoding the attached wiegand.srzip should result in two decodes of the 36 bit value 0010001010011001000000100100010000 Let me know if you need anything more. -- Sean Burford <sburf...@google.com>
wiegand.srzip
Description: Binary data
From deb37953d464c13eda8e4b0e866228ac03ee1b9c Mon Sep 17 00:00:00 2001 From: Sean Burford <sburf...@google.com> Date: Wed, 27 Apr 2016 10:22:39 +1000 Subject: [PATCH 1/1] Add wiegand decoder. --- decoders/wiegand/__init__.py | 29 +++++++++ decoders/wiegand/pd.py | 140 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 169 insertions(+) create mode 100644 decoders/wiegand/__init__.py create mode 100644 decoders/wiegand/pd.py diff --git a/decoders/wiegand/__init__.py b/decoders/wiegand/__init__.py new file mode 100644 index 0000000..20f51f8 --- /dev/null +++ b/decoders/wiegand/__init__.py @@ -0,0 +1,29 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2016 Sean Burford <sburf...@google.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 2 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 St, Fifth Floor, Boston, MA 02110-1301 USA +## + +''' +The Wiegand interface is a de facto wiring standard commonly used to connect +a card swipe mechanism to the rest of an electronic entry system. + +Details: +https://en.wikipedia.org/wiki/Wiegand_interface +''' + +from .pd import Decoder diff --git a/decoders/wiegand/pd.py b/decoders/wiegand/pd.py new file mode 100644 index 0000000..fc49e0b --- /dev/null +++ b/decoders/wiegand/pd.py @@ -0,0 +1,140 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2016 Sean Burford <sburf...@google.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 2 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 St, Fifth Floor, Boston, MA 02110-1301 USA +## + +import sigrokdecode as srd + +class Decoder(srd.Decoder): + api_version = 2 + id = 'wiegand' + name = 'Wiegand' + longname = 'Wiegand Interface' + desc = 'Wiegand Interface for electronic entry systems.' + license = 'gplv2+' + inputs = ['logic'] + outputs = ['wiegand'] + channels = ( + {'id': 'd0', 'name': 'D0', 'desc': 'Data 0 line'}, + {'id': 'd1', 'name': 'D1', 'desc': 'Data 1 line'}, + ) + options = ( + {'id': 'active', 'desc': 'Data lines active level', + 'default': 'low', 'values': ('low', 'high')}, + {'id': 'bitwidth_ms', 'desc': 'Single bit width in milliseconds', + 'default': '4', 'values': ('1', '2', '4', '8', '16', '32')}, + ) + annotations = ( + ('bits', 'Bits'), + ('state', 'State'), + ) + annotation_rows = ( + ('bits', 'Binary Value', (0,)), + ('state', 'Stream State', (1,)), + ) + binary = () + + def __init__(self, **kwargs): + super(Decoder, self).__init__(**kwargs) + + self._out_annotation = None + self._samples_per_bit = 10 + + self._d0_prev = None + self._d1_prev = None + + self._state = None + self._state_start = None + + self._bit = None + self._bit_start = None + self._bit_end = None + self._bits = [] + + def start(self): + """Register output types and verify user supplied decoder values.""" + self.out_annotation = self.register(srd.OUTPUT_ANN) + self._active = self.options['active'] == 'high' and 1 or 0 + self._inactive = 1 - self._active + + def metadata(self, key, value): + """Receive decoder metadata about the data stream.""" + if key == srd.SRD_CONF_SAMPLERATE: + ms_per_sample = 1000 * (1.0 / value) + ms_per_bit = float(self.options['bitwidth_ms']) + self._samples_per_bit = int(max(1, int(ms_per_bit / ms_per_sample))) + + def _update_state(self, samplenum, state, bit=None): + """Update state and bit values when they change.""" + if self._bit is not None: + self._bits.append(self._bit) + self.put(self._bit_start, samplenum, self.out_annotation, + [0, [str(self._bit),]]) + self._bit = bit + self._bit_start = samplenum + if bit is not None: + # Set a timeout so that the final bit ends. + self._bit_end = samplenum + self._samples_per_bit + else: + self._bit_end = None + + if state != self._state: + ann = None + if self._state == 'data': + accum_bits = ''.join(str(x) for x in self._bits) + ann = [1, ['%d bits %s' % (len(self._bits), accum_bits), + '%d bits' % len(self._bits)]] + elif self._state == 'invalid': + ann = [1, [self._state]] + if ann: + self.put(self._state_start, samplenum, self.out_annotation, ann) + self._state_start = samplenum + self._state = state + self._bits = [] + + def decode(self, startsample, endsample, data): + """Receive and decode samples.""" + for samplenum, (d0, d1) in data: + if d0 == self._d0_prev and d1 == self._d1_prev: + if self._bit_end and samplenum >= self._bit_end: + if (d0, d1) == (self._inactive, self._inactive): + self._update_state(samplenum, 'idle') + else: + self._update_state(samplenum, 'invalid') + continue + + if self._state in (None, 'idle', 'data'): + if (d0, d1) == (self._active, self._inactive): + self._update_state(samplenum, 'data', 0) + elif (d0, d1) == (self._inactive, self._active): + self._update_state(samplenum, 'data', 1) + elif (d0, d1) == (self._active, self._active): + self._update_state(samplenum, 'invalid') + elif self._state == 'invalid': + # Wait until we see an idle state before leaving invalid. + # This prevents inverted lines from being misread. + if (d0, d1) == (self._inactive, self._inactive): + self._update_state(samplenum, 'idle') + + self._d0_prev, self._d1_prev = d0, d1 + + def report(self): + return '%s: %s D0 %d D1 %d (active on %d), %d samples per bit' % ( + self.name, self._state, self._d0_prev, self._d1_prev, + self._active, self._samples_per_bit) + -- 2.8.0.rc3.226.g39d4020
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