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