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27ea5bac | 1 | ## |
2 | ## This file is part of the libsigrokdecode project. | |
3 | ## | |
4 | ## Copyright (C) 2016 Fabian J. Stumpf <sigrok@fabianstumpf.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 | |
4539e9ca | 17 | ## along with this program; if not, see <http://www.gnu.org/licenses/>. |
27ea5bac | 18 | ## |
19 | ||
20 | import sigrokdecode as srd | |
21 | ||
22 | class Decoder(srd.Decoder): | |
ba2eca6e | 23 | api_version = 3 |
27ea5bac | 24 | id = 'dmx512' |
25 | name = 'DMX512' | |
26 | longname = 'Digital MultipleX 512' | |
27 | desc = 'Professional lighting control protocol.' | |
28 | license = 'gplv2+' | |
29 | inputs = ['logic'] | |
30 | outputs = ['dmx512'] | |
31 | channels = ( | |
32 | {'id': 'dmx', 'name': 'DMX data', 'desc': 'Any DMX data line'}, | |
33 | ) | |
34 | annotations = ( | |
35 | ('bit', 'Bit'), | |
36 | ('break', 'Break'), | |
37 | ('mab', 'Mark after break'), | |
38 | ('startbit', 'Start bit'), | |
39 | ('stopbits', 'Stop bit'), | |
40 | ('startcode', 'Start code'), | |
41 | ('channel', 'Channel'), | |
42 | ('interframe', 'Interframe'), | |
43 | ('interpacket', 'Interpacket'), | |
44 | ('data', 'Data'), | |
45 | ('error', 'Error'), | |
46 | ) | |
47 | annotation_rows = ( | |
48 | ('name', 'Logical', (1, 2, 5, 6, 7, 8)), | |
49 | ('data', 'Data', (9,)), | |
50 | ('bits', 'Bits', (0, 3, 4)), | |
51 | ('errors', 'Errors', (10,)), | |
52 | ) | |
53 | ||
54 | def __init__(self): | |
55 | self.samplerate = None | |
56 | self.sample_usec = None | |
27ea5bac | 57 | self.run_start = -1 |
58 | self.run_bit = 0 | |
59 | self.state = 'FIND BREAK' | |
60 | ||
61 | def start(self): | |
62 | self.out_ann = self.register(srd.OUTPUT_ANN) | |
63 | ||
64 | def metadata(self, key, value): | |
65 | if key == srd.SRD_CONF_SAMPLERATE: | |
66 | self.samplerate = value | |
67 | self.sample_usec = 1 / value * 1000000 | |
68 | self.skip_per_bit = int(4 / self.sample_usec) | |
69 | ||
70 | def putr(self, data): | |
71 | self.put(self.run_start, self.samplenum, self.out_ann, data) | |
72 | ||
ba2eca6e | 73 | def decode(self): |
27ea5bac | 74 | if not self.samplerate: |
75 | raise SamplerateError('Cannot decode without samplerate.') | |
ba2eca6e | 76 | while True: |
27ea5bac | 77 | # Seek for an interval with no state change with a length between |
78 | # 88 and 1000000 us (BREAK). | |
79 | if self.state == 'FIND BREAK': | |
e992ae3a | 80 | (dmx,) = self.wait({0: 'h' if self.run_bit == 0 else 'l'}) |
27ea5bac | 81 | runlen = (self.samplenum - self.run_start) * self.sample_usec |
82 | if runlen > 88 and runlen < 1000000: | |
83 | self.putr([1, ['Break']]) | |
84 | self.bit_break = self.run_bit | |
85 | self.state = 'MARK MAB' | |
86 | self.channel = 0 | |
87 | elif runlen >= 1000000: | |
88 | # Error condition. | |
89 | self.putr([10, ['Invalid break length']]) | |
e992ae3a | 90 | self.run_bit = dmx |
27ea5bac | 91 | self.run_start = self.samplenum |
92 | # Directly following the BREAK is the MARK AFTER BREAK. | |
93 | elif self.state == 'MARK MAB': | |
e992ae3a | 94 | (dmx,) = self.wait({0: 'h' if self.run_bit == 0 else 'l'}) |
27ea5bac | 95 | self.putr([2, ['MAB']]) |
96 | self.state = 'READ BYTE' | |
97 | self.channel = 0 | |
98 | self.bit = 0 | |
e992ae3a | 99 | self.aggreg = dmx |
27ea5bac | 100 | self.run_start = self.samplenum |
101 | # Mark and read a single transmitted byte | |
102 | # (start bit, 8 data bits, 2 stop bits). | |
103 | elif self.state == 'READ BYTE': | |
1b9ef18b | 104 | (dmx,) = self.wait() |
27ea5bac | 105 | self.next_sample = self.run_start + (self.bit + 1) * self.skip_per_bit |
e992ae3a | 106 | self.aggreg += dmx |
27ea5bac | 107 | if self.samplenum != self.next_sample: |
108 | continue | |
109 | bit_value = 0 if round(self.aggreg/self.skip_per_bit) == self.bit_break else 1 | |
110 | ||
111 | if self.bit == 0: | |
112 | self.byte = 0 | |
113 | self.putr([3, ['Start bit']]) | |
114 | if bit_value != 0: | |
115 | # (Possibly) invalid start bit, mark but don't fail. | |
116 | self.put(self.samplenum, self.samplenum, | |
117 | self.out_ann, [10, ['Invalid start bit']]) | |
118 | elif self.bit >= 9: | |
119 | self.put(self.samplenum - self.skip_per_bit, | |
120 | self.samplenum, self.out_ann, [4, ['Stop bit']]) | |
121 | if bit_value != 1: | |
122 | # Invalid stop bit, mark. | |
123 | self.put(self.samplenum, self.samplenum, | |
124 | self.out_ann, [10, ['Invalid stop bit']]) | |
125 | if self.bit == 10: | |
126 | # On invalid 2nd stop bit, search for new break. | |
e992ae3a | 127 | self.run_bit = dmx |
27ea5bac | 128 | self.state = 'FIND BREAK' |
129 | else: | |
130 | # Label and process one bit. | |
131 | self.put(self.samplenum - self.skip_per_bit, | |
132 | self.samplenum, self.out_ann, [0, [str(bit_value)]]) | |
133 | self.byte |= bit_value << (self.bit - 1) | |
134 | ||
135 | # Label a complete byte. | |
136 | if self.bit == 10: | |
137 | if self.channel == 0: | |
138 | d = [5, ['Start code']] | |
139 | else: | |
140 | d = [6, ['Channel ' + str(self.channel)]] | |
141 | self.put(self.run_start, self.next_sample, self.out_ann, d) | |
142 | self.put(self.run_start + self.skip_per_bit, | |
143 | self.next_sample - 2 * self.skip_per_bit, | |
144 | self.out_ann, [9, [str(self.byte) + ' / ' + \ | |
145 | str(hex(self.byte))]]) | |
146 | # Continue by scanning the IFT. | |
147 | self.channel += 1 | |
148 | self.run_start = self.samplenum | |
e992ae3a | 149 | self.run_bit = dmx |
27ea5bac | 150 | self.state = 'MARK IFT' |
151 | ||
e992ae3a | 152 | self.aggreg = dmx |
27ea5bac | 153 | self.bit += 1 |
154 | # Mark the INTERFRAME-TIME between bytes / INTERPACKET-TIME between packets. | |
155 | elif self.state == 'MARK IFT': | |
e992ae3a | 156 | (dmx,) = self.wait({0: 'h' if self.run_bit == 0 else 'l'}) |
27ea5bac | 157 | if self.channel > 512: |
158 | self.putr([8, ['Interpacket']]) | |
159 | self.state = 'FIND BREAK' | |
e992ae3a | 160 | self.run_bit = dmx |
27ea5bac | 161 | self.run_start = self.samplenum |
162 | else: | |
163 | self.putr([7, ['Interframe']]) | |
164 | self.state = 'READ BYTE' | |
165 | self.bit = 0 | |
166 | self.run_start = self.samplenum |