2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2015 Benjamin Larsson <benjamin@southpole.se>
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, see <http://www.gnu.org/licenses/>.
20 import sigrokdecode as srd
22 class SamplerateError(Exception):
25 class Decoder(srd.Decoder):
29 longname = 'RFID EM4100'
30 desc = 'EM4100 100-150kHz RFID protocol.'
35 {'id': 'data', 'name': 'Data', 'desc': 'Data line'},
38 {'id': 'polarity', 'desc': 'Polarity', 'default': 'active-high',
39 'values': ('active-low', 'active-high')},
40 {'id': 'datarate' , 'desc': 'Data rate', 'default': 64,
41 'values': (64, 32, 16)},
42 # {'id': 'coding', 'desc': 'Bit coding', 'default': 'biphase',
43 # 'values': ('biphase', 'manchester', 'psk')},
44 {'id': 'coilfreq', 'desc': 'Coil frequency', 'default': 125000},
49 ('version-customer', 'Version/customer'),
51 ('rowparity-ok', 'Row parity OK'),
52 ('rowparity-err', 'Row parity error'),
53 ('colparity-ok', 'Column parity OK'),
54 ('colparity-err', 'Column parity error'),
55 ('stopbit', 'Stop bit'),
59 ('bits', 'Bits', (0,)),
60 ('fields', 'Fields', (1, 2, 3, 4, 5, 6, 7, 8)),
61 ('tags', 'Tags', (9,)),
65 self.samplerate = None
67 self.last_samplenum = None
68 self.lastlast_samplenum = None
71 self.halfbit_limit = 0
84 self.data_col_parity = [0, 0, 0, 0, 0, 0]
85 self.col_parity = [0, 0, 0, 0, 0, 0]
87 self.all_row_parity_ok = True
88 self.col_parity_pos = []
90 def metadata(self, key, value):
91 if key == srd.SRD_CONF_SAMPLERATE:
92 self.samplerate = value
93 self.bit_width = (self.samplerate / self.options['coilfreq']) * self.options['datarate']
94 self.halfbit_limit = self.bit_width/2 + self.bit_width/4
95 self.polarity = 0 if self.options['polarity'] == 'active-low' else 1
98 self.out_ann = self.register(srd.OUTPUT_ANN)
100 def putbit(self, bit, ss, es):
101 self.put(ss, es, self.out_ann, [0, [str(bit)]])
102 if self.state == 'HEADER':
104 if self.first_one > 0:
106 if self.first_one == 9:
107 self.put(self.ss_first, es, self.out_ann,
108 [1, ['Header', 'Head', 'He', 'H']])
110 self.state = 'PAYLOAD'
112 if self.first_one == 0:
120 if self.state == 'PAYLOAD':
121 self.payload_cnt += 1
122 if self.data_bits == 0:
127 if self.data_bits == 5:
128 s = 'Version/customer' if self.payload_cnt <= 10 else 'Data'
129 c = 2 if self.payload_cnt <= 10 else 3
130 self.put(self.ss_data, ss, self.out_ann,
131 [c, [s + ': %X' % self.data, '%X' % self.data]])
132 s = 'OK' if self.data_parity == bit else 'ERROR'
133 c = 4 if s == 'OK' else 5
135 self.all_row_parity_ok = False
136 self.put(ss, es, self.out_ann,
137 [c, ['Row parity: ' + s, 'RP: ' + s, 'RP', 'R']])
138 self.tag = (self.tag << 4) | self.data
140 if self.payload_cnt == 50:
141 self.state = 'TRAILER'
144 self.data_parity ^= bit
145 self.data_col_parity[self.data_bits] ^= bit
146 self.data = (self.data << 1) | bit
149 if self.state == 'TRAILER':
150 self.payload_cnt += 1
151 if self.data_bits == 0:
156 self.col_parity[self.data_bits] = bit
157 self.col_parity_pos.append([ss, es])
159 if self.data_bits == 5:
160 self.put(ss, es, self.out_ann, [8, ['Stop bit', 'SB', 'S']])
162 for i in range(1, 5):
163 s = 'OK' if self.data_col_parity[i] == \
164 self.col_parity[i] else 'ERROR'
165 c = 6 if s == 'OK' else 7
166 self.put(self.col_parity_pos[i - 1][0],
167 self.col_parity_pos[i - 1][1], self.out_ann,
168 [c, ['Column parity %d: %s' % (i, s),
169 'CP%d: %s' % (i, s), 'CP%d' % i, 'C']])
171 # Emit an annotation for valid-looking tags.
172 all_col_parity_ok = (self.data_col_parity[1:5] == self.col_parity[1:5])
173 if all_col_parity_ok and self.all_row_parity_ok:
174 self.put(self.ss_first, es, self.out_ann,
175 [9, ['Tag: %010X' % self.tag, 'Tag', 'T']])
180 if self.payload_cnt == 5:
181 self.state = 'HEADER'
183 self.data_col_parity = [0, 0, 0, 0, 0, 0]
184 self.col_parity = [0, 0, 0, 0, 0, 0]
185 self.col_parity_pos = []
186 self.all_row_parity_ok = True
188 def manchester_decode(self, pl, pp, pin):
189 bit = self.oldpin ^ self.polarity
190 if pl > self.halfbit_limit:
191 es = int(self.samplenum - pl/2)
192 if self.oldpl > self.halfbit_limit:
193 ss = int(self.oldsamplenum - self.oldpl/2)
195 ss = int(self.oldsamplenum - self.oldpl)
196 self.putbit(bit, ss, es)
197 self.last_bit_pos = int(self.samplenum - pl/2)
199 es = int(self.samplenum)
200 if self.oldpl > self.halfbit_limit:
201 ss = int(self.oldsamplenum - self.oldpl/2)
202 self.putbit(bit, ss, es)
203 self.last_bit_pos = int(self.samplenum)
205 if self.last_bit_pos <= self.oldsamplenum - self.oldpl:
206 ss = int(self.oldsamplenum - self.oldpl)
207 self.putbit(bit, ss, es)
208 self.last_bit_pos = int(self.samplenum)
211 if not self.samplerate:
212 raise SamplerateError('Cannot decode without samplerate.')
214 # Initialize internal state from the very first sample.
215 (pin,) = self.wait({'skip': 1})
217 self.last_samplenum = self.samplenum
218 self.lastlast_samplenum = self.samplenum
219 self.last_edge = self.samplenum
222 self.oldsamplenum = 0
223 self.last_bit_pos = 0
226 # Ignore identical samples, only process edges.
227 (pin,) = self.wait({0: 'e'})
228 pl = self.samplenum - self.oldsamplenum
230 self.manchester_decode(pl, pp, pin)
233 self.oldsamplenum = self.samplenum