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am230x: rename reset() helper method
[libsigrokdecode.git] / decoders / am230x / pd.py
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1##
2## This file is part of the libsigrokdecode project.
3##
4## Copyright (C) 2014 Johannes Roemer <jroemer@physik.uni-wuerzburg.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/>.
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18##
19
20import sigrokdecode as srd
21
22# Define valid timing values (in microseconds).
23timing = {
24 'START LOW' : {'min': 750, 'max': 25000},
25 'START HIGH' : {'min': 10, 'max': 10000},
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26 'RESPONSE LOW' : {'min': 50, 'max': 90},
27 'RESPONSE HIGH' : {'min': 50, 'max': 90},
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28 'BIT LOW' : {'min': 45, 'max': 90},
29 'BIT 0 HIGH' : {'min': 20, 'max': 35},
30 'BIT 1 HIGH' : {'min': 65, 'max': 80},
31}
32
33class SamplerateError(Exception):
34 pass
35
36class Decoder(srd.Decoder):
b6bac00c 37 api_version = 3
b1f2b85b 38 id = 'am230x'
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39 name = 'AM230x/DHTxx/RHTxx'
40 longname = 'Aosong AM230x/DHTxx/RHTxx'
41 desc = 'Aosong AM230x/DHTxx/RHTxx humidity/temperature sensor protocol.'
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42 license = 'gplv2+'
43 inputs = ['logic']
44 outputs = ['am230x']
45 channels = (
46 {'id': 'sda', 'name': 'SDA', 'desc': 'Single wire serial data line'},
47 )
48 options = (
cda1352a 49 {'id': 'device', 'desc': 'Device type',
e2ba53bb 50 'default': 'am230x', 'values': ('am230x/rht', 'dht11')},
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51 )
52 annotations = (
53 ('start', 'Start'),
54 ('response', 'Response'),
55 ('bit', 'Bit'),
56 ('end', 'End'),
57 ('byte', 'Byte'),
58 ('humidity', 'Relative humidity in percent'),
59 ('temperature', 'Temperature in degrees Celsius'),
60 ('checksum', 'Checksum'),
61 )
62 annotation_rows = (
63 ('bits', 'Bits', (0, 1, 2, 3)),
64 ('bytes', 'Bytes', (4,)),
65 ('results', 'Results', (5, 6, 7)),
66 )
67
68 def putfs(self, data):
69 self.put(self.fall, self.samplenum, self.out_ann, data)
70
71 def putb(self, data):
72 self.put(self.bytepos[-1], self.samplenum, self.out_ann, data)
73
74 def putv(self, data):
75 self.put(self.bytepos[-2], self.samplenum, self.out_ann, data)
76
779c540d 77 def reset_variables(self):
b1f2b85b 78 self.state = 'WAIT FOR START LOW'
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79 self.fall = 0
80 self.rise = 0
81 self.bits = []
82 self.bytepos = []
83
84 def is_valid(self, name):
85 dt = 0
86 if name.endswith('LOW'):
87 dt = self.samplenum - self.fall
88 elif name.endswith('HIGH'):
89 dt = self.samplenum - self.rise
90 if dt >= self.cnt[name]['min'] and dt <= self.cnt[name]['max']:
91 return True
92 return False
93
94 def bits2num(self, bitlist):
95 number = 0
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96 for i in range(len(bitlist)):
97 number += bitlist[-1 - i] * 2**i
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98 return number
99
100 def calculate_humidity(self, bitlist):
101 h = 0
cda1352a 102 if self.options['device'] == 'dht11':
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103 h = self.bits2num(bitlist[0:8])
104 else:
105 h = self.bits2num(bitlist) / 10
106 return h
107
108 def calculate_temperature(self, bitlist):
109 t = 0
cda1352a 110 if self.options['device'] == 'dht11':
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111 t = self.bits2num(bitlist[0:8])
112 else:
113 t = self.bits2num(bitlist[1:]) / 10
114 if bitlist[0] == 1:
115 t = -t
116 return t
117
118 def calculate_checksum(self, bitlist):
119 checksum = 0
47405f47 120 for i in range(8, len(bitlist) + 1, 8):
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121 checksum += self.bits2num(bitlist[i-8:i])
122 return checksum % 256
123
92b7b49f 124 def __init__(self):
b1f2b85b 125 self.samplerate = None
779c540d 126 self.reset_variables()
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127
128 def start(self):
129 self.out_ann = self.register(srd.OUTPUT_ANN)
130
131 def metadata(self, key, value):
132 if key != srd.SRD_CONF_SAMPLERATE:
133 return
134 self.samplerate = value
135 # Convert microseconds to sample counts.
136 self.cnt = {}
137 for e in timing:
138 self.cnt[e] = {}
139 for t in timing[e]:
140 self.cnt[e][t] = timing[e][t] * self.samplerate / 1000000
141
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142 def handle_byte(self, bit):
143 self.bits.append(bit)
144 self.putfs([2, ['Bit: %d' % bit, '%d' % bit]])
145 self.fall = self.samplenum
146 self.state = 'WAIT FOR BIT HIGH'
147 if len(self.bits) % 8 == 0:
148 byte = self.bits2num(self.bits[-8:])
149 self.putb([4, ['Byte: %#04x' % byte, '%#04x' % byte]])
150 if len(self.bits) == 16:
151 h = self.calculate_humidity(self.bits[-16:])
152 self.putv([5, ['Humidity: %.1f %%' % h, 'RH = %.1f %%' % h]])
153 elif len(self.bits) == 32:
154 t = self.calculate_temperature(self.bits[-16:])
155 self.putv([6, ['Temperature: %.1f °C' % t, 'T = %.1f °C' % t]])
156 elif len(self.bits) == 40:
157 parity = self.bits2num(self.bits[-8:])
158 if parity == self.calculate_checksum(self.bits[0:32]):
159 self.putb([7, ['Checksum: OK', 'OK']])
160 else:
161 self.putb([7, ['Checksum: not OK', 'NOK']])
162 self.state = 'WAIT FOR END'
163 self.bytepos.append(self.samplenum)
164
b6bac00c 165 def decode(self):
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166 if not self.samplerate:
167 raise SamplerateError('Cannot decode without samplerate.')
b6bac00c 168 while True:
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169 # State machine.
170 if self.state == 'WAIT FOR START LOW':
b6bac00c 171 self.wait({0: 'f'})
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172 self.fall = self.samplenum
173 self.state = 'WAIT FOR START HIGH'
174 elif self.state == 'WAIT FOR START HIGH':
b6bac00c 175 self.wait({0: 'r'})
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176 if self.is_valid('START LOW'):
177 self.rise = self.samplenum
178 self.state = 'WAIT FOR RESPONSE LOW'
179 else:
779c540d 180 self.reset_variables()
b1f2b85b 181 elif self.state == 'WAIT FOR RESPONSE LOW':
b6bac00c 182 self.wait({0: 'f'})
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183 if self.is_valid('START HIGH'):
184 self.putfs([0, ['Start', 'S']])
185 self.fall = self.samplenum
186 self.state = 'WAIT FOR RESPONSE HIGH'
187 else:
779c540d 188 self.reset_variables()
b1f2b85b 189 elif self.state == 'WAIT FOR RESPONSE HIGH':
b6bac00c 190 self.wait({0: 'r'})
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191 if self.is_valid('RESPONSE LOW'):
192 self.rise = self.samplenum
193 self.state = 'WAIT FOR FIRST BIT'
194 else:
779c540d 195 self.reset_variables()
b1f2b85b 196 elif self.state == 'WAIT FOR FIRST BIT':
b6bac00c 197 self.wait({0: 'f'})
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198 if self.is_valid('RESPONSE HIGH'):
199 self.putfs([1, ['Response', 'R']])
200 self.fall = self.samplenum
201 self.bytepos.append(self.samplenum)
202 self.state = 'WAIT FOR BIT HIGH'
203 else:
779c540d 204 self.reset_variables()
b1f2b85b 205 elif self.state == 'WAIT FOR BIT HIGH':
b6bac00c 206 self.wait({0: 'r'})
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207 if self.is_valid('BIT LOW'):
208 self.rise = self.samplenum
209 self.state = 'WAIT FOR BIT LOW'
210 else:
779c540d 211 self.reset_variables()
b1f2b85b 212 elif self.state == 'WAIT FOR BIT LOW':
b6bac00c 213 self.wait({0: 'f'})
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214 if self.is_valid('BIT 0 HIGH'):
215 bit = 0
216 elif self.is_valid('BIT 1 HIGH'):
217 bit = 1
218 else:
779c540d 219 self.reset_variables()
b1f2b85b 220 continue
0b6bc7f9 221 self.handle_byte(bit)
b1f2b85b 222 elif self.state == 'WAIT FOR END':
b6bac00c 223 self.wait({0: 'r'})
b1f2b85b 224 self.putfs([3, ['End', 'E']])
779c540d 225 self.reset_variables()