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44f7ba18 | 1 | ## |
50bd5d25 | 2 | ## This file is part of the libsigrokdecode project. |
44f7ba18 UH |
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 | ||
21 | # National LM75 (and compatibles) temperature sensor protocol decoder | |
22 | ||
23 | # TODO: Better support for various LM75 compatible devices. | |
24 | ||
25 | import sigrokdecode as srd | |
26 | ||
27 | # LM75 only supports 9 bit resolution, compatible devices usually 9-12 bits. | |
28 | resolution = { | |
29 | # CONFIG[6:5]: <resolution> | |
30 | 0x00: 9, | |
31 | 0x01: 10, | |
32 | 0x02: 11, | |
33 | 0x03: 12, | |
34 | } | |
35 | ||
36 | ft = { | |
37 | # CONFIG[4:3]: <fault tolerance setting> | |
38 | 0x00: 1, | |
39 | 0x01: 2, | |
40 | 0x02: 4, | |
41 | 0x03: 6, | |
42 | } | |
43 | ||
44 | class Decoder(srd.Decoder): | |
45 | api_version = 1 | |
46 | id = 'lm75' | |
47 | name = 'LM75' | |
48 | longname = 'National LM75' | |
d523eae6 | 49 | desc = 'National LM75 (and compatibles) temperature sensor.' |
44f7ba18 UH |
50 | license = 'gplv2+' |
51 | inputs = ['i2c'] | |
52 | outputs = ['lm75'] | |
53 | probes = [] | |
54 | optional_probes = [ | |
55 | {'id': 'os', 'name': 'OS', 'desc': 'Overtemperature shutdown'}, | |
56 | {'id': 'a0', 'name': 'A0', 'desc': 'I2C slave address input 0'}, | |
57 | {'id': 'a1', 'name': 'A1', 'desc': 'I2C slave address input 1'}, | |
58 | {'id': 'a2', 'name': 'A2', 'desc': 'I2C slave address input 2'}, | |
59 | ] | |
60 | options = { | |
61 | 'sensor': ['Sensor type', 'lm75'], | |
62 | 'resolution': ['Resolution', 9], # 9-12 bit, sensor/config dependent | |
63 | } | |
64 | annotations = [ | |
65 | ['Celsius', 'Temperature in degrees Celsius'], | |
f84d82c0 | 66 | ['Kelvin', 'Temperature in Kelvin'], |
44f7ba18 UH |
67 | ['Text (verbose)', 'Human-readable text (verbose)'], |
68 | ['Text', 'Human-readable text'], | |
69 | ['Warnings', 'Human-readable warnings'], | |
70 | ] | |
71 | ||
72 | def __init__(self, **kwargs): | |
73 | self.state = 'IDLE' | |
74 | self.reg = 0x00 # Currently selected register | |
75 | self.databytes = [] | |
76 | self.mintemp = 0 | |
77 | self.maxtemp = 0 | |
b5d3ea69 | 78 | self.avgvalues = [] |
44f7ba18 UH |
79 | |
80 | def start(self, metadata): | |
81 | # self.out_proto = self.add(srd.OUTPUT_PROTO, 'lm75') | |
82 | self.out_ann = self.add(srd.OUTPUT_ANN, 'lm75') | |
83 | ||
84 | def report(self): | |
b5d3ea69 UH |
85 | # TODO: print() or self.put() or return xyz, or... ? |
86 | avg = sum(self.avgvalues) / len(self.avgvalues) | |
87 | temperatures = (self.mintemp, self.maxtemp, avg) | |
88 | # TODO: Configurable report() output, e.g. for Kelvin. | |
89 | return 'Min/max/avg temperature: %f/%f/%f °C' % temperatures | |
44f7ba18 UH |
90 | |
91 | def putx(self, data): | |
92 | # Helper for annotations which span exactly one I2C packet. | |
93 | self.put(self.ss, self.es, self.out_ann, data) | |
94 | ||
95 | def putb(self, data): | |
96 | # Helper for annotations which span a block of I2C packets. | |
97 | self.put(self.block_start, self.block_end, self.out_ann, data) | |
98 | ||
99 | def warn_upon_invalid_slave(self, addr): | |
100 | # LM75 and compatible devices have a 7-bit I2C slave address where | |
101 | # the 4 MSBs are fixed to 1001, and the 3 LSBs are configurable. | |
102 | # Thus, valid slave addresses (1001xxx) range from 0x48 to 0x4f. | |
103 | if addr not in range(0x48, 0x4f + 1): | |
104 | s = 'Warning: I2C slave 0x%02x not an LM75 compatible sensor.' | |
105 | self.putx([4, [s % addr]]) | |
106 | ||
5b30440e | 107 | def output_temperature(self, s, rw): |
44f7ba18 UH |
108 | # TODO: Support for resolutions other than 9 bit. |
109 | before, after = self.databytes[0], (self.databytes[1] >> 7) * 5 | |
110 | celsius = float('%d.%d' % (before, after)) | |
111 | kelvin = celsius + 273.15 | |
112 | self.putb([0, ['%s: %.1f °C' % (s, celsius)]]) | |
f84d82c0 | 113 | self.putb([1, ['%s: %.1f K' % (s, kelvin)]]) |
44f7ba18 | 114 | |
86aac5f0 UH |
115 | # Warn about the temperature register (0x00) being read-only. |
116 | if s == 'Temperature' and rw == 'WRITE': | |
117 | s = 'Warning: The temperature register is read-only!' | |
118 | self.putb([4, [s]]) | |
119 | ||
44f7ba18 UH |
120 | # Keep some statistics. Can be output in report(), for example. |
121 | if celsius < self.mintemp: | |
122 | self.mintemp = celsius | |
123 | if celsius > self.maxtemp: | |
124 | self.maxtemp = celsius | |
b5d3ea69 | 125 | self.avgvalues.append(celsius) |
44f7ba18 | 126 | |
5b30440e | 127 | def handle_temperature_reg(self, b, s, rw): |
44f7ba18 UH |
128 | # Common helper for the temperature/T_HYST/T_OS registers. |
129 | if len(self.databytes) == 0: | |
130 | self.block_start = self.ss | |
131 | self.databytes.append(b) | |
132 | return | |
133 | self.databytes.append(b) | |
134 | self.block_end = self.es | |
5b30440e | 135 | self.output_temperature(s, rw) |
44f7ba18 UH |
136 | self.databytes = [] |
137 | ||
5b30440e | 138 | def handle_reg_0x00(self, b, rw): |
44f7ba18 | 139 | # Temperature register (16bits, read-only). |
5b30440e | 140 | self.handle_temperature_reg(b, 'Temperature', rw) |
44f7ba18 | 141 | |
5b30440e | 142 | def handle_reg_0x01(self, b, rw): |
44f7ba18 UH |
143 | # Configuration register (8 bits, read/write). |
144 | # TODO: Bit-exact annotation ranges. | |
145 | ||
146 | sd = b & (1 << 0) | |
147 | tmp = 'normal operation' if (sd == 0) else 'shutdown mode' | |
148 | s = 'SD = %d: %s\n' % (sd, tmp) | |
149 | s2 = 'SD = %s, ' % tmp | |
150 | ||
151 | cmp_int = b & (1 << 1) | |
152 | tmp = 'comparator' if (cmp_int == 0) else 'interrupt' | |
153 | s += 'CMP/INT = %d: %s mode\n' % (cmp_int, tmp) | |
154 | s2 += 'CMP/INT = %s, ' % tmp | |
155 | ||
156 | pol = b & (1 << 2) | |
157 | tmp = 'low' if (pol == 0) else 'high' | |
158 | s += 'POL = %d: OS polarity is active-%s\n' % (pol, tmp) | |
159 | s2 += 'POL = active-%s, ' % tmp | |
160 | ||
161 | bits = (b & ((1 << 4) | (1 << 3))) >> 3 | |
162 | s += 'Fault tolerance setting: %d bit(s)\n' % ft[bits] | |
163 | s2 += 'FT = %d' % ft[bits] | |
164 | ||
165 | # Not supported by LM75, but by various compatible devices. | |
166 | if self.options['sensor'] != 'lm75': # TODO | |
167 | bits = (b & ((1 << 6) | (1 << 5))) >> 5 | |
168 | s += 'Resolution: %d bits\n' % resolution[bits] | |
169 | s2 += ', resolution = %d' % resolution[bits] | |
170 | ||
171 | self.putx([2, [s]]) | |
172 | self.putx([3, [s2]]) | |
173 | ||
5b30440e | 174 | def handle_reg_0x02(self, b, rw): |
44f7ba18 | 175 | # T_HYST register (16 bits, read/write). |
5b30440e | 176 | self.handle_temperature_reg(b, 'T_HYST trip temperature', rw) |
44f7ba18 | 177 | |
5b30440e | 178 | def handle_reg_0x03(self, b, rw): |
44f7ba18 | 179 | # T_OS register (16 bits, read/write). |
5b30440e | 180 | self.handle_temperature_reg(b, 'T_OS trip temperature', rw) |
44f7ba18 UH |
181 | |
182 | def decode(self, ss, es, data): | |
183 | cmd, databyte = data | |
184 | ||
185 | # Store the start/end samples of this I2C packet. | |
186 | self.ss, self.es = ss, es | |
187 | ||
188 | # State machine. | |
189 | if self.state == 'IDLE': | |
190 | # Wait for an I2C START condition. | |
191 | if cmd != 'START': | |
192 | return | |
193 | self.state = 'GET SLAVE ADDR' | |
194 | elif self.state == 'GET SLAVE ADDR': | |
195 | # Wait for an address read/write operation. | |
5b30440e | 196 | if cmd in ('ADDRESS READ', 'ADDRESS WRITE'): |
44f7ba18 | 197 | self.warn_upon_invalid_slave(databyte) |
5b30440e UH |
198 | self.state = cmd[8:] + ' REGS' # READ REGS / WRITE REGS |
199 | elif self.state in ('READ REGS', 'WRITE REGS'): | |
200 | if cmd in ('DATA READ', 'DATA WRITE'): | |
44f7ba18 | 201 | handle_reg = getattr(self, 'handle_reg_0x%02x' % self.reg) |
5b30440e | 202 | handle_reg(databyte, cmd[5:]) # READ / WRITE |
44f7ba18 UH |
203 | elif cmd == 'STOP': |
204 | # TODO: Any output? | |
205 | self.state = 'IDLE' | |
206 | else: | |
207 | # self.putx([0, ['Ignoring: %s (data=%s)' % (cmd, databyte)]]) | |
208 | pass | |
209 | else: | |
210 | raise Exception('Invalid state: %s' % self.state) | |
211 |