From: Sean Burford Date: Tue, 10 May 2016 07:25:21 +0000 (+1000) Subject: Add wiegand decoder. X-Git-Tag: libsigrokdecode-0.5.0~172 X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=1b1de5693cc7229c01502b23bc659a3b09af8868;p=libsigrokdecode.git Add wiegand decoder. --- 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 +## +## 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..6194194 --- /dev/null +++ b/decoders/wiegand/pd.py @@ -0,0 +1,134 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2016 Sean Burford +## +## 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,)), + ) + + def __init__(self, **kwargs): + self._samples_per_bit = 10 + + self._d0_prev = None + self._d1_prev = None + + self._state = None + self._ss_state = None + + self.ss_bit = None + self.es_bit = None + self._bit = None + self._bits = [] + + def start(self): + 'Register output types and verify user supplied decoder values.' + self.out_ann = 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, 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.ss_bit, self.samplenum, self.out_ann, + [0, [str(self._bit)]]) + self._bit = bit + self.ss_bit = self.samplenum + if bit is not None: + # Set a timeout so that the final bit ends. + self.es_bit = self.samplenum + self._samples_per_bit + else: + self.es_bit = 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._ss_state, self.samplenum, self.out_ann, ann) + self._ss_state = self.samplenum + self._state = state + self._bits = [] + + def decode(self, ss, es, data): + for self.samplenum, (d0, d1) in data: + if d0 == self._d0_prev and d1 == self._d1_prev: + if self.es_bit and self.samplenum >= self.es_bit: + if (d0, d1) == (self._inactive, self._inactive): + self._update_state('idle') + else: + self._update_state('invalid') + continue + + if self._state in (None, 'idle', 'data'): + if (d0, d1) == (self._active, self._inactive): + self._update_state('data', 0) + elif (d0, d1) == (self._inactive, self._active): + self._update_state('data', 1) + elif (d0, d1) == (self._active, self._active): + self._update_state('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('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)