mirror of
https://github.com/DreamSourceLab/DSView.git
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312 lines
12 KiB
Python
312 lines
12 KiB
Python
##
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## This file is part of the libsigrokdecode project.
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##
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## Copyright (C) 2012-2016 Uwe Hermann <uwe@hermann-uwe.de>
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##
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## This program is free software; you can redistribute it and/or modify
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## it under the terms of the GNU General Public License as published by
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## the Free Software Foundation; either version 2 of the License, or
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## (at your option) any later version.
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##
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## This program is distributed in the hope that it will be useful,
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## but WITHOUT ANY WARRANTY; without even the implied warranty of
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## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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## GNU General Public License for more details.
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##
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## You should have received a copy of the GNU General Public License
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## along with this program; if not, see <http://www.gnu.org/licenses/>.
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##
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import sigrokdecode as srd
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import calendar
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from common.srdhelper import bcd2int
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class SamplerateError(Exception):
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pass
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class Decoder(srd.Decoder):
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api_version = 3
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id = 'dcf77'
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name = 'DCF77'
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longname = 'DCF77 time protocol'
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desc = 'European longwave time signal (77.5kHz carrier signal).'
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license = 'gplv2+'
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inputs = ['logic']
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outputs = []
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tags = ['Clock/timing']
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channels = (
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{'id': 'data', 'name': 'DATA', 'desc': 'DATA line'},
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)
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annotations = (
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('start-of-minute', 'Start of minute'),
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('special-bits', 'Special bits (civil warnings, weather forecast)'),
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('call-bit', 'Call bit'),
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('summer-time', 'Summer time announcement'),
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('cest', 'CEST bit'),
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('cet', 'CET bit'),
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('leap-second', 'Leap second bit'),
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('start-of-time', 'Start of encoded time'),
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('minute', 'Minute'),
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('minute-parity', 'Minute parity bit'),
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('hour', 'Hour'),
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('hour-parity', 'Hour parity bit'),
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('day', 'Day of month'),
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('day-of-week', 'Day of week'),
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('month', 'Month'),
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('year', 'Year'),
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('date-parity', 'Date parity bit'),
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('raw-bits', 'Raw bits'),
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('unknown-bits', 'Unknown bits'),
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('warnings', 'Human-readable warnings'),
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)
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annotation_rows = (
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('bits', 'Bits', (17, 18)),
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('fields', 'Fields', tuple(range(0, 16 + 1))),
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('warnings', 'Warnings', (19,)),
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)
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def __init__(self):
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self.reset()
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def reset(self):
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self.samplerate = None
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self.state = 'WAIT FOR RISING EDGE'
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self.ss_bit = self.ss_bit_old = self.es_bit = self.ss_block = 0
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self.datebits = []
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self.bitcount = 0 # Counter for the DCF77 bits (0..58)
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self.dcf77_bitnumber_is_known = 0
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def start(self):
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self.out_ann = self.register(srd.OUTPUT_ANN)
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def metadata(self, key, value):
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if key == srd.SRD_CONF_SAMPLERATE:
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self.samplerate = value
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def putx(self, data):
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# Annotation for a single DCF77 bit.
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self.put(self.ss_bit, self.es_bit, self.out_ann, data)
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def putb(self, data):
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# Annotation for a multi-bit DCF77 field.
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self.put(self.ss_block, self.samplenum, self.out_ann, data)
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# TODO: Which range to use? Only the 100ms/200ms or full second?
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def handle_dcf77_bit(self, bit):
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c = self.bitcount
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# Create one annotation for each DCF77 bit (containing the 0/1 value).
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# Use 'Unknown DCF77 bit x: val' if we're not sure yet which of the
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# 0..58 bits it is (because we haven't seen a 'new minute' marker yet).
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# Otherwise, use 'DCF77 bit x: val'.
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s = 'B' if self.dcf77_bitnumber_is_known else 'Unknown b'
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ann = 17 if self.dcf77_bitnumber_is_known else 18
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self.putx([ann, ['%sit %d: %d' % (s, c, bit), '%d' % bit]])
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# If we're not sure yet which of the 0..58 DCF77 bits we have, return.
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# We don't want to decode bogus data.
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if not self.dcf77_bitnumber_is_known:
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return
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# Collect bits 36-58, we'll need them for a parity check later.
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if c in range(36, 58 + 1):
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self.datebits.append(bit)
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# Output specific "decoded" annotations for the respective DCF77 bits.
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if c == 0:
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# Start of minute: DCF bit 0.
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if bit == 0:
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self.putx([0, ['Start of minute (always 0)',
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'Start of minute', 'SoM']])
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else:
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self.putx([19, ['Start of minute != 0', 'SoM != 0']])
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elif c in range(1, 14 + 1):
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# Special bits (civil warnings, weather forecast): DCF77 bits 1-14.
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if c == 1:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 1))
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if c == 14:
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s = '{:014b}'.format(self.tmp)
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self.putb([1, ['Special bits: %s' % s, 'SB: %s' % s]])
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elif c == 15:
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s = '' if (bit == 1) else 'not '
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self.putx([2, ['Call bit: %sset' % s, 'CB: %sset' % s]])
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# TODO: Previously this bit indicated use of the backup antenna.
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elif c == 16:
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s = '' if (bit == 1) else 'not '
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x = 'yes' if (bit == 1) else 'no'
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self.putx([3, ['Summer time announcement: %sactive' % s,
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'Summer time: %sactive' % s,
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'Summer time: %s' % x, 'ST: %s' % x]])
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elif c == 17:
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s = '' if (bit == 1) else 'not '
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x = 'yes' if (bit == 1) else 'no'
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self.putx([4, ['CEST: %sin effect' % s, 'CEST: %s' % x]])
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elif c == 18:
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s = '' if (bit == 1) else 'not '
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x = 'yes' if (bit == 1) else 'no'
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self.putx([5, ['CET: %sin effect' % s, 'CET: %s' % x]])
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elif c == 19:
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s = '' if (bit == 1) else 'not '
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x = 'yes' if (bit == 1) else 'no'
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self.putx([6, ['Leap second announcement: %sactive' % s,
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'Leap second: %sactive' % s,
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'Leap second: %s' % x, 'LS: %s' % x]])
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elif c == 20:
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# Start of encoded time: DCF bit 20.
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if bit == 1:
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self.putx([7, ['Start of encoded time (always 1)',
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'Start of encoded time', 'SoeT']])
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else:
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self.putx([19, ['Start of encoded time != 1', 'SoeT != 1']])
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elif c in range(21, 27 + 1):
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# Minutes (0-59): DCF77 bits 21-27 (BCD format).
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if c == 21:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 21))
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if c == 27:
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m = bcd2int(self.tmp)
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self.putb([8, ['Minutes: %d' % m, 'Min: %d' % m]])
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elif c == 28:
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# Even parity over minute bits (21-28): DCF77 bit 28.
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self.tmp |= (bit << (c - 21))
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parity = bin(self.tmp).count('1')
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s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
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self.putx([9, ['Minute parity: %s' % s, 'Min parity: %s' % s]])
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elif c in range(29, 34 + 1):
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# Hours (0-23): DCF77 bits 29-34 (BCD format).
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if c == 29:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 29))
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if c == 34:
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self.putb([10, ['Hours: %d' % bcd2int(self.tmp)]])
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elif c == 35:
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# Even parity over hour bits (29-35): DCF77 bit 35.
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self.tmp |= (bit << (c - 29))
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parity = bin(self.tmp).count('1')
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s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
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self.putx([11, ['Hour parity: %s' % s]])
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elif c in range(36, 41 + 1):
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# Day of month (1-31): DCF77 bits 36-41 (BCD format).
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if c == 36:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 36))
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if c == 41:
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self.putb([12, ['Day: %d' % bcd2int(self.tmp)]])
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elif c in range(42, 44 + 1):
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# Day of week (1-7): DCF77 bits 42-44 (BCD format).
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# A value of 1 means Monday, 7 means Sunday.
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if c == 42:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 42))
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if c == 44:
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d = bcd2int(self.tmp)
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try:
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dn = calendar.day_name[d - 1] # day_name[0] == Monday
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self.putb([13, ['Day of week: %d (%s)' % (d, dn),
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'DoW: %d (%s)' % (d, dn)]])
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except IndexError:
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self.putb([19, ['Day of week: %d (%s)' % (d, 'invalid'),
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'DoW: %d (%s)' % (d, 'inv')]])
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elif c in range(45, 49 + 1):
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# Month (1-12): DCF77 bits 45-49 (BCD format).
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if c == 45:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 45))
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if c == 49:
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m = bcd2int(self.tmp)
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try:
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mn = calendar.month_name[m] # month_name[1] == January
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self.putb([14, ['Month: %d (%s)' % (m, mn),
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'Mon: %d (%s)' % (m, mn)]])
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except IndexError:
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self.putb([19, ['Month: %d (%s)' % (m, 'invalid'),
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'Mon: %d (%s)' % (m, 'inv')]])
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elif c in range(50, 57 + 1):
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# Year (0-99): DCF77 bits 50-57 (BCD format).
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if c == 50:
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self.tmp = bit
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self.ss_block = self.ss_bit
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else:
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self.tmp |= (bit << (c - 50))
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if c == 57:
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self.putb([15, ['Year: %d' % bcd2int(self.tmp)]])
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elif c == 58:
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# Even parity over date bits (36-58): DCF77 bit 58.
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parity = self.datebits.count(1)
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s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
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self.putx([16, ['Date parity: %s' % s, 'DP: %s' % s]])
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self.datebits = []
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else:
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self.putx([19, ['Invalid DCF77 bit: %d' % c,
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'Invalid bit: %d' % c, 'Inv: %d' % c]])
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def decode(self):
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if not self.samplerate:
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raise SamplerateError('Cannot decode without samplerate.')
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while True:
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if self.state == 'WAIT FOR RISING EDGE':
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# Wait until the next rising edge occurs.
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self.wait({0: 'r'})
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# Save the sample number where the DCF77 bit begins.
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self.ss_bit = self.samplenum
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# Calculate the length (in ms) between two rising edges.
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len_edges = self.ss_bit - self.ss_bit_old
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len_edges_ms = int((len_edges / self.samplerate) * 1000)
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# The time between two rising edges is usually around 1000ms.
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# For DCF77 bit 59, there is no rising edge at all, i.e. the
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# time between DCF77 bit 59 and DCF77 bit 0 (of the next
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# minute) is around 2000ms. Thus, if we see an edge with a
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# 2000ms distance to the last one, this edge marks the
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# beginning of a new minute (and DCF77 bit 0 of that minute).
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if len_edges_ms in range(1600, 2400 + 1):
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self.bitcount = 0
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self.ss_bit_old = self.ss_bit
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self.dcf77_bitnumber_is_known = 1
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self.ss_bit_old = self.ss_bit
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self.state = 'GET BIT'
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elif self.state == 'GET BIT':
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# Wait until the next falling edge occurs.
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self.wait({0: 'f'})
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# Save the sample number where the DCF77 bit ends.
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self.es_bit = self.samplenum
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# Calculate the length (in ms) of the current high period.
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len_high = self.samplenum - self.ss_bit
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len_high_ms = int((len_high / self.samplerate) * 1000)
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# If the high signal was 100ms long, that encodes a 0 bit.
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# If it was 200ms long, that encodes a 1 bit.
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if len_high_ms in range(40, 160 + 1):
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bit = 0
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elif len_high_ms in range(161, 260 + 1):
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bit = 1
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else:
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bit = -1
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if bit in (0, 1):
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self.handle_dcf77_bit(bit)
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self.bitcount += 1
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else:
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self.putx([19, ['Invalid bit timing', 'Inv timing', 'Inv']])
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self.state = 'WAIT FOR RISING EDGE'
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