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output/analog: Display META packets
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ac913e5c 1/*
50985c20 2 * This file is part of the libsigrok project.
ac913e5c 3 *
71f1302b 4 * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
ac913e5c
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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
2ea1fdf1 17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
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18 */
19
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20/**
21 * @file
22 *
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23 * Metex 14-bytes ASCII protocol parser.
24 *
e83437ae 25 * @internal
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26 * This should work for various multimeters which use this kind of protocol,
27 * even though there is some variation in which modes each DMM supports.
28 *
29 * It does _not_ work for all Metex DMMs, some use a quite different protocol.
30 */
31
6ec6c43b 32#include <config.h>
ac913e5c 33#include <string.h>
ba464a12 34#include <strings.h>
ac913e5c
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35#include <ctype.h>
36#include <math.h>
37#include <glib.h>
c1aae900 38#include <libsigrok/libsigrok.h>
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39#include "libsigrok-internal.h"
40
3544f848 41#define LOG_PREFIX "metex14"
ac913e5c 42
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43/** Parse value from buf, byte 2-8. */
44static int parse_value(const uint8_t *buf, struct metex14_info *info,
e677490e 45 float *result, int *exponent)
ac913e5c 46{
e677490e 47 int i, is_ol, cnt, dot_pos;
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48 char valstr[7 + 1];
49
50 /* Strip all spaces from bytes 2-8. */
51 memset(&valstr, 0, 7 + 1);
52 for (i = 0, cnt = 0; i < 7; i++) {
53 if (buf[2 + i] != ' ')
54 valstr[cnt++] = buf[2 + i];
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55 }
56
57 /* Bytes 5-7: Over limit (various forms) */
58 is_ol = 0;
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59 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, ".OL")) ? 1 : 0;
60 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "O.L")) ? 1 : 0;
61 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "OL.")) ? 1 : 0;
62 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "OL")) ? 1 : 0;
63 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-.OL")) ? 1 : 0;
64 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-O.L")) ? 1 : 0;
65 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL.")) ? 1 : 0;
66 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL")) ? 1 : 0;
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67 if (is_ol != 0) {
68 sr_spew("Over limit.");
69 *result = INFINITY;
70 return SR_OK;
71 }
72
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73 /* Logic functions */
74 if (!strcmp((const char *)&valstr, "READY") ||
75 !strcmp((const char *)&valstr, "FLOAT")) {
76 *result = INFINITY;
77 info->is_logic = TRUE;
78 } else if (!strcmp((const char *)&valstr, "Hi")) {
79 *result = 1.0;
80 info->is_logic = TRUE;
81 } else if (!strcmp((const char *)&valstr, "Lo")) {
82 *result = 0.0;
83 info->is_logic = TRUE;
84 }
85 if (info->is_logic)
86 return SR_OK;
87
1a807c13
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88 /* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
89 sscanf((const char *)&valstr, "%f", result);
ac913e5c 90
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91 dot_pos = strcspn(valstr, ".");
92 if (dot_pos < cnt)
93 *exponent = -(cnt - dot_pos - 1);
94 else
95 *exponent = 0;
96
1a807c13 97 sr_spew("The display value is %f.", *result);
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98
99 return SR_OK;
100}
101
102static void parse_flags(const char *buf, struct metex14_info *info)
103{
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104 int i, cnt;
105 char unit[4 + 1];
106 const char *u;
107
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108 /* Bytes 0-1: Measurement mode AC, DC */
109 info->is_ac = !strncmp(buf, "AC", 2);
110 info->is_dc = !strncmp(buf, "DC", 2);
ac913e5c 111
1a807c13 112 /* Bytes 2-8: See parse_value(). */
ac913e5c 113
1a807c13 114 /* Strip all spaces from bytes 9-12. */
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115 memset(&unit, 0, 4 + 1);
116 for (i = 0, cnt = 0; i < 4; i++) {
117 if (buf[9 + i] != ' ')
118 unit[cnt++] = buf[9 + i];
119 }
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120
121 /* Bytes 9-12: Unit */
71f1302b 122 u = (const char *)&unit;
34577da6 123 if (!g_ascii_strcasecmp(u, "A"))
ac913e5c 124 info->is_ampere = TRUE;
34577da6 125 else if (!g_ascii_strcasecmp(u, "mA"))
ac913e5c 126 info->is_milli = info->is_ampere = TRUE;
34577da6 127 else if (!g_ascii_strcasecmp(u, "uA"))
2477fb95 128 info->is_micro = info->is_ampere = TRUE;
34577da6 129 else if (!g_ascii_strcasecmp(u, "V"))
ac913e5c 130 info->is_volt = TRUE;
34577da6 131 else if (!g_ascii_strcasecmp(u, "mV"))
ac913e5c 132 info->is_milli = info->is_volt = TRUE;
34577da6 133 else if (!g_ascii_strcasecmp(u, "Ohm"))
ac913e5c 134 info->is_ohm = TRUE;
34577da6 135 else if (!g_ascii_strcasecmp(u, "KOhm"))
ac913e5c 136 info->is_kilo = info->is_ohm = TRUE;
34577da6 137 else if (!g_ascii_strcasecmp(u, "MOhm"))
ac913e5c 138 info->is_mega = info->is_ohm = TRUE;
34577da6 139 else if (!g_ascii_strcasecmp(u, "pF"))
c02dc3e2 140 info->is_pico = info->is_farad = TRUE;
34577da6 141 else if (!g_ascii_strcasecmp(u, "nF"))
ac913e5c 142 info->is_nano = info->is_farad = TRUE;
34577da6 143 else if (!g_ascii_strcasecmp(u, "uF"))
ac913e5c 144 info->is_micro = info->is_farad = TRUE;
34577da6 145 else if (!g_ascii_strcasecmp(u, "KHz"))
ac913e5c 146 info->is_kilo = info->is_hertz = TRUE;
34577da6 147 else if (!g_ascii_strcasecmp(u, "C"))
ac913e5c 148 info->is_celsius = TRUE;
34577da6 149 else if (!g_ascii_strcasecmp(u, "DB"))
9871215c 150 info->is_decibel = TRUE;
34577da6 151 else if (!g_ascii_strcasecmp(u, ""))
9871215c 152 info->is_unitless = TRUE;
ac913e5c 153
e83437ae 154 /* Bytes 0-1: Measurement mode, except AC/DC */
d9251a2c 155 info->is_resistance = !strncmp(buf, "OH", 2) ||
e83437ae 156 (!strncmp(buf, " ", 2) && info->is_ohm);
d9251a2c 157 info->is_capacity = !strncmp(buf, "CA", 2) ||
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158 (!strncmp(buf, " ", 2) && info->is_farad);
159 info->is_temperature = !strncmp(buf, "TE", 2);
d9251a2c 160 info->is_diode = !strncmp(buf, "DI", 2) ||
e83437ae 161 (!strncmp(buf, " ", 2) && info->is_volt && info->is_milli);
d9251a2c 162 info->is_frequency = !strncmp(buf, "FR", 2) ||
e83437ae 163 (!strncmp(buf, " ", 2) && info->is_hertz);
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164 info->is_gain = !strncmp(buf, "DB", 2);
165 info->is_hfe = !strncmp(buf, "HF", 2) ||
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166 (!strncmp(buf, " ", 2) && !info->is_volt && !info->is_ohm &&
167 !info->is_logic && !info->is_farad && !info->is_hertz);
168 /*
169 * Note:
170 * - Protocol doesn't distinguish "resistance" from "beep" mode.
171 * - "DB" shows the logarithmic ratio of input voltage to a
172 * pre-stored (user-changeable) value in the DMM.
173 */
174
ac913e5c
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175 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
176}
177
b02bb45f 178static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
e677490e 179 int *exponent, const struct metex14_info *info)
ac913e5c 180{
e677490e 181 int factor = 0;
ac913e5c 182 /* Factors */
c02dc3e2 183 if (info->is_pico)
e677490e 184 factor -= 12;
ac913e5c 185 if (info->is_nano)
e677490e 186 factor -= 9;
ac913e5c 187 if (info->is_micro)
e677490e 188 factor -= 6;
ac913e5c 189 if (info->is_milli)
e677490e 190 factor -= 3;
ac913e5c 191 if (info->is_kilo)
e677490e 192 factor += 3;
ac913e5c 193 if (info->is_mega)
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194 factor += 6;
195 *floatval *= powf(10, factor);
196 *exponent += factor;
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197
198 /* Measurement modes */
199 if (info->is_volt) {
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200 analog->meaning->mq = SR_MQ_VOLTAGE;
201 analog->meaning->unit = SR_UNIT_VOLT;
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202 }
203 if (info->is_ampere) {
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204 analog->meaning->mq = SR_MQ_CURRENT;
205 analog->meaning->unit = SR_UNIT_AMPERE;
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206 }
207 if (info->is_ohm) {
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208 analog->meaning->mq = SR_MQ_RESISTANCE;
209 analog->meaning->unit = SR_UNIT_OHM;
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210 }
211 if (info->is_hertz) {
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212 analog->meaning->mq = SR_MQ_FREQUENCY;
213 analog->meaning->unit = SR_UNIT_HERTZ;
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214 }
215 if (info->is_farad) {
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216 analog->meaning->mq = SR_MQ_CAPACITANCE;
217 analog->meaning->unit = SR_UNIT_FARAD;
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218 }
219 if (info->is_celsius) {
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220 analog->meaning->mq = SR_MQ_TEMPERATURE;
221 analog->meaning->unit = SR_UNIT_CELSIUS;
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222 }
223 if (info->is_diode) {
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224 analog->meaning->mq = SR_MQ_VOLTAGE;
225 analog->meaning->unit = SR_UNIT_VOLT;
ac913e5c 226 }
9871215c 227 if (info->is_gain) {
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228 analog->meaning->mq = SR_MQ_GAIN;
229 analog->meaning->unit = SR_UNIT_DECIBEL_VOLT;
9871215c
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230 }
231 if (info->is_hfe) {
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232 analog->meaning->mq = SR_MQ_GAIN;
233 analog->meaning->unit = SR_UNIT_UNITLESS;
9871215c 234 }
e83437ae 235 if (info->is_logic) {
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236 analog->meaning->mq = SR_MQ_GAIN;
237 analog->meaning->unit = SR_UNIT_UNITLESS;
e83437ae 238 }
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239
240 /* Measurement related flags */
241 if (info->is_ac)
b02bb45f 242 analog->meaning->mqflags |= SR_MQFLAG_AC;
ac913e5c 243 if (info->is_dc)
b02bb45f 244 analog->meaning->mqflags |= SR_MQFLAG_DC;
a6ed50f4 245 if (info->is_diode)
b02bb45f 246 analog->meaning->mqflags |= SR_MQFLAG_DIODE;
ac913e5c
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247}
248
249static gboolean flags_valid(const struct metex14_info *info)
250{
251 int count;
252
253 /* Does the packet have more than one multiplier? */
254 count = 0;
c02dc3e2 255 count += (info->is_pico) ? 1 : 0;
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256 count += (info->is_nano) ? 1 : 0;
257 count += (info->is_micro) ? 1 : 0;
258 count += (info->is_milli) ? 1 : 0;
259 count += (info->is_kilo) ? 1 : 0;
260 count += (info->is_mega) ? 1 : 0;
261 if (count > 1) {
ec5186f9 262 sr_dbg("More than one multiplier detected in packet.");
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263 return FALSE;
264 }
265
266 /* Does the packet "measure" more than one type of value? */
267 count = 0;
268 count += (info->is_ac) ? 1 : 0;
269 count += (info->is_dc) ? 1 : 0;
270 count += (info->is_resistance) ? 1 : 0;
271 count += (info->is_capacity) ? 1 : 0;
272 count += (info->is_temperature) ? 1 : 0;
273 count += (info->is_diode) ? 1 : 0;
274 count += (info->is_frequency) ? 1 : 0;
275 if (count > 1) {
ec5186f9 276 sr_dbg("More than one measurement type detected in packet.");
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277 return FALSE;
278 }
279
280 /* Both AC and DC set? */
281 if (info->is_ac && info->is_dc) {
ec5186f9 282 sr_dbg("Both AC and DC flags detected in packet.");
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283 return FALSE;
284 }
285
286 return TRUE;
287}
288
c4f2dfd0 289#ifdef HAVE_LIBSERIALPORT
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290SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
291{
292 const uint8_t wbuf = 'D';
293
294 sr_spew("Requesting DMM packet.");
295
379e95c5 296 return serial_write_blocking(serial, &wbuf, 1, 0);
e90cf076 297}
c4f2dfd0 298#endif
e90cf076 299
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300SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
301{
302 struct metex14_info info;
303
304 memset(&info, 0x00, sizeof(struct metex14_info));
305 parse_flags((const char *)buf, &info);
306
307 if (!flags_valid(&info))
308 return FALSE;
309
310 if (buf[13] != '\r')
311 return FALSE;
312
313 return TRUE;
314}
315
316/**
317 * Parse a protocol packet.
318 *
1fbab466 319 * @param buf Buffer containing the protocol packet. Must not be NULL.
ac913e5c 320 * @param floatval Pointer to a float variable. That variable will be modified
1fbab466 321 * in-place depending on the protocol packet. Must not be NULL.
b02bb45f 322 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
ac913e5c 323 * filled with data according to the protocol packet.
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324 * Must not be NULL.
325 * @param info Pointer to a struct metex14_info. The struct will be filled
326 * with data according to the protocol packet. Must not be NULL.
ac913e5c
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327 *
328 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
329 * 'analog' variable contents are undefined and should not be used.
330 */
331SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
b02bb45f 332 struct sr_datafeed_analog *analog, void *info)
ac913e5c 333{
e677490e 334 int ret, exponent = 0;
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335 struct metex14_info *info_local;
336
337 info_local = (struct metex14_info *)info;
ac913e5c 338
e82d7dbc
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339 /* Don't print byte 13. That one contains the carriage return. */
340 sr_dbg("DMM packet: \"%.13s\"", buf);
341
e83437ae
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342 memset(info_local, 0x00, sizeof(struct metex14_info));
343
e677490e 344 if ((ret = parse_value(buf, info_local, floatval, &exponent)) != SR_OK) {
ec5186f9 345 sr_dbg("Error parsing value: %d.", ret);
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346 return ret;
347 }
348
1fbab466 349 parse_flags((const char *)buf, info_local);
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350 handle_flags(analog, floatval, &exponent, info_local);
351
d9251a2c 352 analog->encoding->digits = -exponent;
e677490e 353 analog->spec->spec_digits = -exponent;
ac913e5c
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354
355 return SR_OK;
356}