2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
6 ## This program is free software; you can redistribute it and/or modify
7 ## it under the terms of the GNU General Public License as published by
8 ## the Free Software Foundation; either version 2 of the License, or
9 ## (at your option) any later version.
11 ## This program is distributed in the hope that it will be useful,
12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 ## GNU General Public License for more details.
16 ## You should have received a copy of the GNU General Public License
17 ## along with this program; if not, write to the Free Software
18 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 import sigrokdecode as srd
24 # Return the specified BCD number (max. 8 bits) as integer.
26 return (b & 0x0f) + ((b >> 4) * 10)
28 class Decoder(srd.Decoder):
32 longname = 'DCF77 time protocol'
33 desc = 'European longwave time signal (77.5kHz carrier signal).'
38 {'id': 'data', 'name': 'DATA', 'desc': 'DATA line'},
43 ['start-of-minute', 'Start of minute'],
44 ['special-bits', 'Special bits (civil warnings, weather forecast)'],
45 ['call-bit', 'Call bit'],
46 ['summer-time', 'Summer time announcement'],
49 ['leap-second', 'Leap second bit'],
50 ['start-of-time', 'Start of encoded time'],
52 ['minute-parity', 'Minute parity bit'],
54 ['hour-parity', 'Hour parity bit'],
55 ['day', 'Day of month'],
56 ['day-of-week', 'Day of week'],
59 ['date-parity', 'Date parity bit'],
60 ['raw-bits', 'Raw bits'],
61 ['unknown-bits', 'Unknown bits'],
62 ['warnings', 'Human-readable warnings'],
65 def __init__(self, **kwargs):
66 self.samplerate = None
67 self.state = 'WAIT FOR RISING EDGE'
71 self.ss_bit = self.ss_bit_old = self.es_bit = self.ss_block = 0
73 self.bitcount = 0 # Counter for the DCF77 bits (0..58)
74 self.dcf77_bitnumber_is_known = 0
77 # self.out_proto = self.register(srd.OUTPUT_PYTHON)
78 self.out_ann = self.register(srd.OUTPUT_ANN)
80 def metadata(self, key, value):
81 if key == srd.SRD_CONF_SAMPLERATE:
82 self.samplerate = value
85 # Annotation for a single DCF77 bit.
86 self.put(self.ss_bit, self.es_bit, self.out_ann, data)
89 # Annotation for a multi-bit DCF77 field.
90 self.put(self.ss_block, self.samplenum, self.out_ann, data)
92 # TODO: Which range to use? Only the 100ms/200ms or full second?
93 def handle_dcf77_bit(self, bit):
96 # Create one annotation for each DCF77 bit (containing the 0/1 value).
97 # Use 'Unknown DCF77 bit x: val' if we're not sure yet which of the
98 # 0..58 bits it is (because we haven't seen a 'new minute' marker yet).
99 # Otherwise, use 'DCF77 bit x: val'.
100 s = 'B' if self.dcf77_bitnumber_is_known else 'Unknown b'
101 ann = 17 if self.dcf77_bitnumber_is_known else 18
102 self.putx([ann, ['%sit %d: %d' % (s, c, bit), '%d' % bit]])
104 # If we're not sure yet which of the 0..58 DCF77 bits we have, return.
105 # We don't want to decode bogus data.
106 if not self.dcf77_bitnumber_is_known:
109 # Collect bits 36-58, we'll need them for a parity check later.
110 if c in range(36, 58 + 1):
111 self.datebits.append(bit)
113 # Output specific "decoded" annotations for the respective DCF77 bits.
115 # Start of minute: DCF bit 0.
117 self.putx([0, ['Start of minute (always 0)',
118 'Start of minute', 'SoM']])
120 self.putx([19, ['Start of minute != 0', 'SoM != 0']])
121 elif c in range(1, 14 + 1):
122 # Special bits (civil warnings, weather forecast): DCF77 bits 1-14.
125 self.ss_block = self.ss_bit
127 self.tmp |= (bit << (c - 1))
129 s = bin(self.tmp)[2:].zfill(14)
130 self.putb([1, ['Special bits: %s' % s, 'SB: %s' % s]])
132 s = '' if (bit == 1) else 'not '
133 self.putx([2, ['Call bit: %sset' % s, 'CB: %sset' % s]])
134 # TODO: Previously this bit indicated use of the backup antenna.
136 s = '' if (bit == 1) else 'not '
137 x = 'yes' if (bit == 1) else 'no'
138 self.putx([3, ['Summer time announcement: %sactive' % s,
139 'Summer time: %sactive' % s,
140 'Summer time: %s' % x, 'ST: %s' % x]])
142 s = '' if (bit == 1) else 'not '
143 x = 'yes' if (bit == 1) else 'no'
144 self.putx([4, ['CEST: %sin effect' % s, 'CEST: %s' % x]])
146 s = '' if (bit == 1) else 'not '
147 x = 'yes' if (bit == 1) else 'no'
148 self.putx([5, ['CET: %sin effect' % s, 'CET: %s' % x]])
150 s = '' if (bit == 1) else 'not '
151 x = 'yes' if (bit == 1) else 'no'
152 self.putx([6, ['Leap second announcement: %sactive' % s,
153 'Leap second: %sactive' % s,
154 'Leap second: %s' % x, 'LS: %s' % x]])
156 # Start of encoded time: DCF bit 20.
158 self.putx([7, ['Start of encoded time (always 1)',
159 'Start of encoded time', 'SoeT']])
161 self.putx([19, ['Start of encoded time != 1', 'SoeT != 1']])
162 elif c in range(21, 27 + 1):
163 # Minutes (0-59): DCF77 bits 21-27 (BCD format).
166 self.ss_block = self.ss_bit
168 self.tmp |= (bit << (c - 21))
170 m = bcd2int(self.tmp)
171 self.putb([8, ['Minutes: %d' % m, 'Min: %d' % m]])
173 # Even parity over minute bits (21-28): DCF77 bit 28.
174 self.tmp |= (bit << (c - 21))
175 parity = bin(self.tmp).count('1')
176 s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
177 self.putx([9, ['Minute parity: %s' % s, 'Min parity: %s' % s]])
178 elif c in range(29, 34 + 1):
179 # Hours (0-23): DCF77 bits 29-34 (BCD format).
182 self.ss_block = self.ss_bit
184 self.tmp |= (bit << (c - 29))
186 self.putb([10, ['Hours: %d' % bcd2int(self.tmp)]])
188 # Even parity over hour bits (29-35): DCF77 bit 35.
189 self.tmp |= (bit << (c - 29))
190 parity = bin(self.tmp).count('1')
191 s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
192 self.putx([11, ['Hour parity: %s' % s]])
193 elif c in range(36, 41 + 1):
194 # Day of month (1-31): DCF77 bits 36-41 (BCD format).
197 self.ss_block = self.ss_bit
199 self.tmp |= (bit << (c - 36))
201 self.putb([12, ['Day: %d' % bcd2int(self.tmp)]])
202 elif c in range(42, 44 + 1):
203 # Day of week (1-7): DCF77 bits 42-44 (BCD format).
204 # A value of 1 means Monday, 7 means Sunday.
207 self.ss_block = self.ss_bit
209 self.tmp |= (bit << (c - 42))
211 d = bcd2int(self.tmp)
212 dn = calendar.day_name[d - 1] # day_name[0] == Monday
213 self.putb([13, ['Day of week: %d (%s)' % (d, dn),
214 'DoW: %d (%s)' % (d, dn)]])
215 elif c in range(45, 49 + 1):
216 # Month (1-12): DCF77 bits 45-49 (BCD format).
219 self.ss_block = self.ss_bit
221 self.tmp |= (bit << (c - 45))
223 m = bcd2int(self.tmp)
224 mn = calendar.month_name[m] # month_name[1] == January
225 self.putx([14, ['Month: %d (%s)' % (m, mn),
226 'Mon: %d (%s)' % (m, mn)]])
227 elif c in range(50, 57 + 1):
228 # Year (0-99): DCF77 bits 50-57 (BCD format).
231 self.ss_block = self.ss_bit
233 self.tmp |= (bit << (c - 50))
235 self.putb([15, ['Year: %d' % bcd2int(self.tmp)]])
237 # Even parity over date bits (36-58): DCF77 bit 58.
238 parity = self.datebits.count(1)
239 s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
240 self.putx([16, ['Date parity: %s' % s, 'DP: %s' %s]])
243 raise Exception('Invalid DCF77 bit: %d' % c)
245 def decode(self, ss, es, data):
246 if self.samplerate is None:
247 raise Exception("Cannot decode without samplerate.")
248 for (self.samplenum, pins) in data:
250 # Ignore identical samples early on (for performance reasons).
251 if self.oldpins == pins:
253 self.oldpins, (val,) = pins, pins
255 if self.state == 'WAIT FOR RISING EDGE':
256 # Wait until the next rising edge occurs.
257 if not (self.oldval == 0 and val == 1):
261 # Save the sample number where the DCF77 bit begins.
262 self.ss_bit = self.samplenum
264 # Calculate the length (in ms) between two rising edges.
265 len_edges = self.ss_bit - self.ss_bit_old
266 len_edges_ms = int((len_edges / self.samplerate) * 1000)
268 # The time between two rising edges is usually around 1000ms.
269 # For DCF77 bit 59, there is no rising edge at all, i.e. the
270 # time between DCF77 bit 59 and DCF77 bit 0 (of the next
271 # minute) is around 2000ms. Thus, if we see an edge with a
272 # 2000ms distance to the last one, this edge marks the
273 # beginning of a new minute (and DCF77 bit 0 of that minute).
274 if len_edges_ms in range(1600, 2400 + 1):
276 self.ss_bit_old = self.ss_bit
277 self.dcf77_bitnumber_is_known = 1
279 self.ss_bit_old = self.ss_bit
280 self.state = 'GET BIT'
282 elif self.state == 'GET BIT':
283 # Wait until the next falling edge occurs.
284 if not (self.oldval == 1 and val == 0):
288 # Save the sample number where the DCF77 bit ends.
289 self.es_bit = self.samplenum
291 # Calculate the length (in ms) of the current high period.
292 len_high = self.samplenum - self.ss_bit
293 len_high_ms = int((len_high / self.samplerate) * 1000)
295 # If the high signal was 100ms long, that encodes a 0 bit.
296 # If it was 200ms long, that encodes a 1 bit.
297 if len_high_ms in range(40, 160 + 1):
299 elif len_high_ms in range(161, 260 + 1):
302 bit = -1 # TODO: Error?
304 # There's no bit 59, make sure none is decoded.
305 if bit in (0, 1) and self.bitcount in range(0, 58 + 1):
306 self.handle_dcf77_bit(bit)
309 self.state = 'WAIT FOR RISING EDGE'
312 raise Exception('Invalid state: %s' % self.state)