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2b0915c1 UH |
1 | ## |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de> | |
5 | ## | |
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. | |
10 | ## | |
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. | |
15 | ## | |
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 | |
19 | ## | |
20 | ||
2b0915c1 | 21 | # DCF77 protocol decoder |
2b0915c1 UH |
22 | |
23 | import sigrokdecode as srd | |
24 | import calendar | |
25 | ||
2b0915c1 | 26 | # Annotation feed formats |
ee3e279c | 27 | ANN_TEXT = 0 |
2b0915c1 UH |
28 | |
29 | # Return the specified BCD number (max. 8 bits) as integer. | |
30 | def bcd2int(b): | |
31 | return (b & 0x0f) + ((b >> 4) * 10) | |
32 | ||
33 | class Decoder(srd.Decoder): | |
a2c2afd9 | 34 | api_version = 1 |
2b0915c1 UH |
35 | id = 'dcf77' |
36 | name = 'DCF77' | |
3d3da57d | 37 | longname = 'DCF77 time protocol' |
a465436e | 38 | desc = 'European longwave time signal (77.5kHz carrier signal).' |
2b0915c1 UH |
39 | license = 'gplv2+' |
40 | inputs = ['logic'] | |
41 | outputs = ['dcf77'] | |
42 | probes = [ | |
43 | {'id': 'data', 'name': 'DATA', 'desc': 'DATA line'}, | |
44 | ] | |
b77614bc | 45 | optional_probes = [ |
decde15e UH |
46 | {'id': 'pon', 'name': 'PON', 'desc': 'TODO'}, |
47 | ] | |
2b0915c1 UH |
48 | options = {} |
49 | annotations = [ | |
ee3e279c UH |
50 | # ANN_TEXT |
51 | ['Text', 'Human-readable text'], | |
2b0915c1 UH |
52 | ] |
53 | ||
54 | def __init__(self, **kwargs): | |
2b716038 | 55 | self.state = 'WAIT FOR RISING EDGE' |
2b0915c1 UH |
56 | self.oldval = None |
57 | self.samplenum = 0 | |
58 | self.bit_start = 0 | |
59 | self.bit_start_old = 0 | |
60 | self.bitcount = 0 # Counter for the DCF77 bits (0..58) | |
61 | self.dcf77_bitnumber_is_known = 0 | |
62 | ||
63 | def start(self, metadata): | |
64 | self.samplerate = metadata['samplerate'] | |
65 | # self.out_proto = self.add(srd.OUTPUT_PROTO, 'dcf77') | |
66 | self.out_ann = self.add(srd.OUTPUT_ANN, 'dcf77') | |
67 | ||
68 | def report(self): | |
69 | pass | |
70 | ||
71 | # TODO: Which range to use? Only the 100ms/200ms or full second? | |
72 | def handle_dcf77_bit(self, bit): | |
73 | c = self.bitcount | |
74 | a = self.out_ann | |
75 | ss = es = 0 # FIXME | |
76 | ||
77 | # Create one annotation for each DCF77 bit (containing the 0/1 value). | |
78 | # Use 'Unknown DCF77 bit x: val' if we're not sure yet which of the | |
79 | # 0..58 bits it is (because we haven't seen a 'new minute' marker yet). | |
80 | # Otherwise, use 'DCF77 bit x: val'. | |
81 | s = '' if self.dcf77_bitnumber_is_known else 'Unknown ' | |
82 | self.put(ss, es, a, [0, ['%sDCF77 bit %d: %d' % (s, c, bit)]]) | |
83 | ||
84 | # If we're not sure yet which of the 0..58 DCF77 bits we have, return. | |
85 | # We don't want to decode bogus data. | |
86 | if not self.dcf77_bitnumber_is_known: | |
87 | return | |
88 | ||
89 | # Output specific "decoded" annotations for the respective DCF77 bits. | |
90 | if c == 0: | |
91 | # Start of minute: DCF bit 0. | |
92 | if bit == 0: | |
93 | self.put(ss, es, a, [0, ['Start of minute (always 0)']]) | |
94 | else: | |
95 | self.put(ss, es, a, [0, ['ERROR: Start of minute != 0']]) | |
96 | elif c in range(1, 14 + 1): | |
97 | # Special bits (civil warnings, weather forecast): DCF77 bits 1-14. | |
98 | if c == 1: | |
99 | self.tmp = bit | |
100 | else: | |
101 | self.tmp |= (bit << (c - 1)) | |
102 | if c == 14: | |
103 | self.put(ss, es, a, [0, ['Special bits: %s' % bin(self.tmp)]]) | |
104 | elif c == 15: | |
105 | s = '' if (bit == 1) else 'not ' | |
106 | self.put(ss, es, a, [0, ['Call bit is %sset' % s]]) | |
107 | # TODO: Previously this bit indicated use of the backup antenna. | |
108 | elif c == 16: | |
109 | s = '' if (bit == 1) else 'not ' | |
110 | self.put(ss, es, a, [0, ['Summer time announcement %sactive' % s]]) | |
111 | elif c == 17: | |
112 | s = '' if (bit == 1) else 'not ' | |
113 | self.put(ss, es, a, [0, ['CEST is %sin effect' % s]]) | |
114 | elif c == 18: | |
115 | s = '' if (bit == 1) else 'not ' | |
116 | self.put(ss, es, a, [0, ['CET is %sin effect' % s]]) | |
117 | elif c == 19: | |
118 | s = '' if (bit == 1) else 'not ' | |
119 | self.put(ss, es, a, [0, ['Leap second announcement %sactive' % s]]) | |
120 | elif c == 20: | |
121 | # Start of encoded time: DCF bit 20. | |
122 | if bit == 1: | |
123 | self.put(ss, es, a, [0, ['Start of encoded time (always 1)']]) | |
124 | else: | |
125 | self.put(ss, es, a, | |
126 | [0, ['ERROR: Start of encoded time != 1']]) | |
127 | elif c in range(21, 27 + 1): | |
128 | # Minutes (0-59): DCF77 bits 21-27 (BCD format). | |
129 | if c == 21: | |
130 | self.tmp = bit | |
131 | else: | |
132 | self.tmp |= (bit << (c - 21)) | |
133 | if c == 27: | |
134 | self.put(ss, es, a, [0, ['Minutes: %d' % bcd2int(self.tmp)]]) | |
135 | elif c == 28: | |
136 | # Even parity over minute bits (21-28): DCF77 bit 28. | |
137 | self.tmp |= (bit << (c - 21)) | |
138 | parity = bin(self.tmp).count('1') | |
139 | s = 'OK' if ((parity % 2) == 0) else 'INVALID!' | |
140 | self.put(ss, es, a, [0, ['Minute parity: %s' % s]]) | |
141 | elif c in range(29, 34 + 1): | |
142 | # Hours (0-23): DCF77 bits 29-34 (BCD format). | |
143 | if c == 29: | |
144 | self.tmp = bit | |
145 | else: | |
146 | self.tmp |= (bit << (c - 29)) | |
147 | if c == 34: | |
148 | self.put(ss, es, a, [0, ['Hours: %d' % bcd2int(self.tmp)]]) | |
149 | elif c == 35: | |
150 | # Even parity over hour bits (29-35): DCF77 bit 35. | |
151 | self.tmp |= (bit << (c - 29)) | |
152 | parity = bin(self.tmp).count('1') | |
153 | s = 'OK' if ((parity % 2) == 0) else 'INVALID!' | |
154 | self.put(ss, es, a, [0, ['Hour parity: %s' % s]]) | |
155 | elif c in range(36, 41 + 1): | |
156 | # Day of month (1-31): DCF77 bits 36-41 (BCD format). | |
157 | if c == 36: | |
158 | self.tmp = bit | |
159 | else: | |
160 | self.tmp |= (bit << (c - 36)) | |
161 | if c == 41: | |
162 | self.put(ss, es, a, [0, ['Day: %d' % bcd2int(self.tmp)]]) | |
163 | elif c in range(42, 44 + 1): | |
164 | # Day of week (1-7): DCF77 bits 42-44 (BCD format). | |
165 | # A value of 1 means Monday, 7 means Sunday. | |
166 | if c == 42: | |
167 | self.tmp = bit | |
168 | else: | |
169 | self.tmp |= (bit << (c - 42)) | |
170 | if c == 44: | |
171 | d = bcd2int(self.tmp) | |
172 | dn = calendar.day_name[d - 1] # day_name[0] == Monday | |
173 | self.put(ss, es, a, [0, ['Day of week: %d (%s)' % (d, dn)]]) | |
174 | elif c in range(45, 49 + 1): | |
175 | # Month (1-12): DCF77 bits 45-49 (BCD format). | |
176 | if c == 45: | |
177 | self.tmp = bit | |
178 | else: | |
179 | self.tmp |= (bit << (c - 45)) | |
180 | if c == 49: | |
181 | m = bcd2int(self.tmp) | |
182 | mn = calendar.month_name[m] # month_name[1] == January | |
183 | self.put(ss, es, a, [0, ['Month: %d (%s)' % (m, mn)]]) | |
184 | elif c in range(50, 57 + 1): | |
185 | # Year (0-99): DCF77 bits 50-57 (BCD format). | |
186 | if c == 50: | |
187 | self.tmp = bit | |
188 | else: | |
189 | self.tmp |= (bit << (c - 50)) | |
190 | if c == 57: | |
191 | self.put(ss, es, a, [0, ['Year: %d' % bcd2int(self.tmp)]]) | |
192 | elif c == 58: | |
193 | # Even parity over date bits (36-58): DCF77 bit 58. | |
194 | self.tmp |= (bit << (c - 50)) | |
195 | parity = bin(self.tmp).count('1') | |
196 | s = 'OK' if ((parity % 2) == 0) else 'INVALID!' | |
197 | self.put(ss, es, a, [0, ['Date parity: %s' % s]]) | |
198 | else: | |
199 | raise Exception('Invalid DCF77 bit: %d' % c) | |
200 | ||
201 | def decode(self, ss, es, data): | |
4180cba9 | 202 | for (self.samplenum, (val)) in data: # TODO: Handle optional PON. |
2b0915c1 | 203 | |
2b716038 | 204 | if self.state == 'WAIT FOR RISING EDGE': |
2b0915c1 UH |
205 | # Wait until the next rising edge occurs. |
206 | if not (self.oldval == 0 and val == 1): | |
207 | self.oldval = val | |
208 | continue | |
209 | ||
210 | # Save the sample number where the DCF77 bit begins. | |
211 | self.bit_start = self.samplenum | |
212 | ||
213 | # Calculate the length (in ms) between two rising edges. | |
214 | len_edges = self.bit_start - self.bit_start_old | |
215 | len_edges_ms = int((len_edges / self.samplerate) * 1000) | |
216 | ||
217 | # The time between two rising edges is usually around 1000ms. | |
218 | # For DCF77 bit 59, there is no rising edge at all, i.e. the | |
219 | # time between DCF77 bit 59 and DCF77 bit 0 (of the next | |
220 | # minute) is around 2000ms. Thus, if we see an edge with a | |
221 | # 2000ms distance to the last one, this edge marks the | |
222 | # beginning of a new minute (and DCF77 bit 0 of that minute). | |
223 | if len_edges_ms in range(1600, 2400 + 1): | |
224 | self.put(ss, es, self.out_ann, [0, ['New minute starts']]) | |
225 | self.bitcount = 0 | |
226 | self.bit_start_old = self.bit_start | |
227 | self.dcf77_bitnumber_is_known = 1 | |
228 | # Don't switch to GET_BIT state this time. | |
229 | continue | |
230 | ||
231 | self.bit_start_old = self.bit_start | |
232 | self.state = GET_BIT | |
233 | ||
234 | elif self.state == GET_BIT: | |
235 | # Wait until the next falling edge occurs. | |
236 | if not (self.oldval == 1 and val == 0): | |
237 | self.oldval = val | |
238 | continue | |
239 | ||
240 | # Calculate the length (in ms) of the current high period. | |
241 | len_high = self.samplenum - self.bit_start | |
242 | len_high_ms = int((len_high / self.samplerate) * 1000) | |
243 | ||
244 | # If the high signal was 100ms long, that encodes a 0 bit. | |
245 | # If it was 200ms long, that encodes a 1 bit. | |
246 | if len_high_ms in range(40, 160 + 1): | |
247 | bit = 0 | |
248 | elif len_high_ms in range(161, 260 + 1): | |
249 | bit = 1 | |
250 | else: | |
251 | bit = -1 # TODO: Error? | |
252 | ||
253 | # TODO: There's no bit 59, make sure none is decoded. | |
254 | if bit in (0, 1) and self.bitcount in range(0, 58 + 1): | |
255 | self.handle_dcf77_bit(bit) | |
256 | self.bitcount += 1 | |
257 | ||
2b716038 | 258 | self.state = 'WAIT FOR RISING EDGE' |
2b0915c1 UH |
259 | |
260 | else: | |
decde15e | 261 | raise Exception('Invalid state: %d' % self.state) |
2b0915c1 UH |
262 | |
263 | self.oldval = val | |
264 |