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1 | /* |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de> | |
5 | * Copyright (C) 2016 Gerhard Sittig <gerhard.sittig@gmx.net> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
20 | ||
21 | /* | |
22 | * Parser for the ASYC-II 16-bytes ASCII protocol (PRINT). | |
23 | * | |
24 | * This should work for various multimeters which use this kind of protocol, | |
25 | * even though there is some variation in which modes each DMM supports. | |
26 | * | |
27 | * This implementation was developed for and tested with a Metrix MX56C, | |
28 | * which is identical to the BK Precision 5390. | |
29 | * See the metex14.c implementation for the 14-byte protocol used by many | |
30 | * other models. | |
31 | */ | |
32 | ||
33 | #include <config.h> | |
34 | #include <ctype.h> | |
35 | #include <glib.h> | |
36 | #include <math.h> | |
37 | #include <stdlib.h> | |
38 | #include <string.h> | |
39 | #include <strings.h> | |
40 | #include <libsigrok/libsigrok.h> | |
41 | #include "libsigrok-internal.h" | |
42 | ||
43 | #define LOG_PREFIX "asycii" | |
44 | ||
45 | /** | |
46 | * Parse sign and value from text buffer, byte 0-6. | |
47 | * | |
48 | * The first character always is the sign (' ' or '-'). Subsequent | |
49 | * positions contain digits, dots, or spaces. Overflow / open inputs | |
50 | * are signalled with several magic literals that cannot get interpreted | |
51 | * as a number, either with 'X' characters in them, or with several | |
52 | * forms of "OL". | |
53 | * | |
54 | * @param[in] buf The text buffer received from the DMM. | |
55 | * @param[out] result A floating point number value. | |
56 | * @param[out] exponent Augments the number value. | |
57 | */ | |
58 | static int parse_value(const char *buf, struct asycii_info *info, | |
59 | float *result, int *exponent) | |
60 | { | |
61 | char valstr[7 + 1]; | |
62 | const char *valp; | |
63 | int i, cnt, is_ol, dot_pos; | |
64 | char *endp; | |
65 | ||
66 | /* | |
67 | * Strip all spaces from bytes 0-6. By copying all | |
68 | * non-space characters into a buffer. | |
69 | */ | |
70 | cnt = 0; | |
71 | for (i = 0; i < 7; i++) { | |
72 | if (buf[i] != ' ') | |
73 | valstr[cnt++] = buf[i]; | |
74 | } | |
75 | valstr[cnt] = '\0'; | |
76 | valp = &valstr[0]; | |
77 | sr_spew("%s(), number buffer [%s]", __func__, valp); | |
78 | ||
79 | /* | |
80 | * Check for "over limit" conditions. Depending on the meter's | |
81 | * selected mode, the textual representation might differ. Test | |
82 | * all known variations. | |
83 | */ | |
84 | is_ol = 0; | |
85 | is_ol += (g_ascii_strcasecmp(valp, ".OL") == 0) ? 1 : 0; | |
86 | is_ol += (g_ascii_strcasecmp(valp, "O.L") == 0) ? 1 : 0; | |
87 | is_ol += (g_ascii_strcasecmp(valp, "-.OL") == 0) ? 1 : 0; | |
88 | is_ol += (g_ascii_strcasecmp(valp, "-O.L") == 0) ? 1 : 0; | |
89 | is_ol += (g_ascii_strncasecmp(valp, "X", 1) == 0) ? 1 : 0; | |
90 | is_ol += (g_ascii_strncasecmp(valp, "-X", 2) == 0) ? 1 : 0; | |
91 | if (is_ol) { | |
92 | sr_spew("%s(), over limit", __func__); | |
93 | *result = INFINITY; | |
94 | return SR_OK; | |
95 | } | |
96 | ||
97 | /* | |
98 | * Convert the textual number representation to a float, and | |
99 | * an exponent. Apply sanity checks (optional sign, digits and | |
100 | * dot expected here, exclusively). | |
101 | */ | |
102 | endp = NULL; | |
103 | *result = strtof(valp, &endp); | |
104 | if (endp == NULL || *endp != '\0') { | |
105 | info->is_invalid = TRUE; | |
106 | sr_spew("%s(), cannot convert number", __func__); | |
107 | return SR_ERR_DATA; | |
108 | } | |
109 | dot_pos = strcspn(valstr, "."); | |
110 | if (dot_pos < cnt) | |
111 | *exponent = -(cnt - dot_pos - 1); | |
112 | else | |
113 | *exponent = 0; | |
114 | sr_spew("%s(), display value is %f", __func__, *result); | |
115 | return SR_OK; | |
116 | } | |
117 | ||
118 | /** | |
119 | * Parse unit and flags from text buffer, bytes 7-14. | |
120 | * | |
121 | * The unit and flags optionally follow the number value for the | |
122 | * measurement. Either can be present or absent. The scale factor | |
123 | * is always at index 7. The unit starts at index 8, and is of | |
124 | * variable length. Flags immediately follow the unit. The remainder | |
125 | * of the text buffer is SPACE padded, and terminated with CR. | |
126 | * | |
127 | * Notice the implementation detail of case *sensitive* comparison. | |
128 | * This would break correct operation. It's essential that e.g. "Vac" | |
129 | * gets split into the "V" unit and the "ac" flag, not into "VA" and | |
130 | * the unknown "c" flag! In the absence of separators or fixed | |
131 | * positions and with ambiguous text (when abbreviated), order of | |
132 | * comparison matters, too. | |
133 | * | |
134 | * @param[in] buf The text buffer received from the DMM. | |
135 | * @param[out] info Broken down measurement details. | |
136 | */ | |
137 | static void parse_flags(const char *buf, struct asycii_info *info) | |
138 | { | |
139 | int i, cnt; | |
140 | char unit[8 + 1]; | |
141 | const char *u; | |
142 | ||
143 | /* Bytes 0-6: Number value, see parse_value(). */ | |
144 | ||
145 | /* Strip spaces from bytes 7-14. */ | |
146 | cnt = 0; | |
147 | for (i = 7; i < 15; i++) { | |
148 | if (buf[i] != ' ') | |
149 | unit[cnt++] = buf[i]; | |
150 | } | |
151 | unit[cnt] = '\0'; | |
152 | u = &unit[0]; | |
153 | sr_spew("%s(): unit/flag buffer [%s]", __func__, u); | |
154 | ||
155 | /* Scan for the scale factor. */ | |
156 | sr_spew("%s(): scanning factor, buffer [%s]", __func__, u); | |
157 | if (*u == 'p') { | |
158 | u++; | |
159 | info->is_pico = TRUE; | |
160 | } else if (*u == 'n') { | |
161 | u++; | |
162 | info->is_nano = TRUE; | |
163 | } else if (*u == 'u') { | |
164 | u++; | |
165 | info->is_micro = TRUE; | |
166 | } else if (*u == 'm') { | |
167 | u++; | |
168 | info->is_milli = TRUE; | |
169 | } else if (*u == ' ') { | |
170 | u++; | |
171 | } else if (*u == 'k') { | |
172 | u++; | |
173 | info->is_kilo = TRUE; | |
174 | } else if (*u == 'M') { | |
175 | u++; | |
176 | info->is_mega = TRUE; | |
177 | } else { | |
178 | /* Absence of a scale modifier is perfectly fine. */ | |
179 | } | |
180 | ||
181 | /* Scan for the measurement unit. */ | |
182 | sr_spew("%s(): scanning unit, buffer [%s]", __func__, u); | |
183 | if (strncmp(u, "A", strlen("A")) == 0) { | |
184 | u += strlen("A"); | |
185 | info->is_ampere = TRUE; | |
186 | } else if (strncmp(u, "VA", strlen("VA")) == 0) { | |
187 | u += strlen("VA"); | |
188 | info->is_volt_ampere = TRUE; | |
189 | } else if (strncmp(u, "V", strlen("V")) == 0) { | |
190 | u += strlen("V"); | |
191 | info->is_volt = TRUE; | |
192 | } else if (strncmp(u, "ohm", strlen("ohm")) == 0) { | |
193 | u += strlen("ohm"); | |
194 | info->is_resistance = TRUE; | |
195 | info->is_ohm = TRUE; | |
196 | } else if (strncmp(u, "F", strlen("F")) == 0) { | |
197 | u += strlen("F"); | |
198 | info->is_capacitance = TRUE; | |
199 | info->is_farad = TRUE; | |
200 | } else if (strncmp(u, "dB", strlen("dB")) == 0) { | |
201 | u += strlen("dB"); | |
202 | info->is_gain = TRUE; | |
203 | info->is_decibel = TRUE; | |
204 | } else if (strncmp(u, "Hz", strlen("Hz")) == 0) { | |
205 | u += strlen("Hz"); | |
206 | info->is_frequency = TRUE; | |
207 | info->is_hertz = TRUE; | |
208 | } else if (strncmp(u, "%", strlen("%")) == 0) { | |
209 | u += strlen("%"); | |
210 | info->is_duty_cycle = TRUE; | |
211 | if (*u == '+') { | |
212 | u++; | |
213 | info->is_duty_pos = TRUE; | |
214 | } else if (*u == '-') { | |
215 | u++; | |
216 | info->is_duty_neg = TRUE; | |
217 | } else { | |
218 | info->is_invalid = TRUE; | |
219 | } | |
220 | } else if (strncmp(u, "Cnt", strlen("Cnt")) == 0) { | |
221 | u += strlen("Cnt"); | |
222 | info->is_pulse_count = TRUE; | |
223 | info->is_unitless = TRUE; | |
224 | if (*u == '+') { | |
225 | u++; | |
226 | info->is_count_pos = TRUE; | |
227 | } else if (*u == '-') { | |
228 | u++; | |
229 | info->is_count_neg = TRUE; | |
230 | } else { | |
231 | info->is_invalid = TRUE; | |
232 | } | |
233 | } else if (strncmp(u, "s", strlen("s")) == 0) { | |
234 | u += strlen("s"); | |
235 | info->is_pulse_width = TRUE; | |
236 | info->is_seconds = TRUE; | |
237 | if (*u == '+') { | |
238 | u++; | |
239 | info->is_period_pos = TRUE; | |
240 | } else if (*u == '-') { | |
241 | u++; | |
242 | info->is_period_neg = TRUE; | |
243 | } else { | |
244 | info->is_invalid = TRUE; | |
245 | } | |
246 | } else { | |
247 | /* Not strictly illegal, but unknown/unsupported. */ | |
248 | sr_spew("%s(): measurement: unsupported", __func__); | |
249 | info->is_invalid = TRUE; | |
250 | } | |
251 | ||
252 | /* Scan for additional flags. */ | |
253 | sr_spew("%s(): scanning flags, buffer [%s]", __func__, u); | |
254 | if (strncmp(u, "ac+dc", strlen("ac+dc")) == 0) { | |
255 | u += strlen("ac+dc"); | |
256 | info->is_ac_and_dc = TRUE; | |
257 | } else if (strncmp(u, "ac", strlen("ac")) == 0) { | |
258 | u += strlen("ac"); | |
259 | info->is_ac = TRUE; | |
260 | } else if (strncmp(u, "dc", strlen("dc")) == 0) { | |
261 | u += strlen("dc"); | |
262 | info->is_dc = TRUE; | |
263 | } else if (strncmp(u, "d", strlen("d")) == 0) { | |
264 | u += strlen("d"); | |
265 | info->is_diode = TRUE; | |
266 | } else if (strncmp(u, "Pk", strlen("Pk")) == 0) { | |
267 | u += strlen("Pk"); | |
268 | if (*u == '+') { | |
269 | u++; | |
270 | info->is_peak_max = TRUE; | |
271 | } else if (*u == '-') { | |
272 | u++; | |
273 | info->is_peak_min = TRUE; | |
274 | } else { | |
275 | info->is_invalid = TRUE; | |
276 | } | |
277 | } else if (strcmp(u, "") == 0) { | |
278 | /* Absence of any flags is acceptable. */ | |
279 | } else { | |
280 | /* Presence of unknown flags is not. */ | |
281 | sr_dbg("%s(): flag: unknown", __func__); | |
282 | info->is_invalid = TRUE; | |
283 | } | |
284 | ||
285 | /* Was all of the received data consumed? */ | |
286 | if (*u != '\0') | |
287 | info->is_invalid = TRUE; | |
288 | ||
289 | /* | |
290 | * Note: | |
291 | * - The protocol does not distinguish between "resistance" | |
292 | * and "continuity". | |
293 | * - Relative measurement and hold cannot get recognized. | |
294 | */ | |
295 | } | |
296 | ||
297 | /** | |
298 | * Fill in a datafeed from previously parsed measurement details. | |
299 | * | |
300 | * @param[out] analog The datafeed which gets filled in. | |
301 | * @param[in] floatval The number value of the measurement. | |
302 | * @param[in] exponent Augments the number value. | |
303 | * @param[in] info Scale and unit and other attributes. | |
304 | */ | |
305 | static void handle_flags(struct sr_datafeed_analog *analog, float *floatval, | |
306 | int *exponent, const struct asycii_info *info) | |
307 | { | |
308 | int factor = 0; | |
309 | ||
310 | /* Factors */ | |
311 | if (info->is_pico) | |
312 | factor -= 12; | |
313 | if (info->is_nano) | |
314 | factor -= 9; | |
315 | if (info->is_micro) | |
316 | factor -= 6; | |
317 | if (info->is_milli) | |
318 | factor -= 3; | |
319 | if (info->is_kilo) | |
320 | factor += 3; | |
321 | if (info->is_mega) | |
322 | factor += 6; | |
323 | *floatval *= powf(10, factor); | |
324 | *exponent += factor; | |
325 | ||
326 | /* Measurement modes */ | |
327 | if (info->is_volt) { | |
328 | analog->meaning->mq = SR_MQ_VOLTAGE; | |
329 | analog->meaning->unit = SR_UNIT_VOLT; | |
330 | } | |
331 | if (info->is_volt_ampere) { | |
332 | analog->meaning->mq = SR_MQ_POWER; | |
333 | analog->meaning->unit = SR_UNIT_VOLT_AMPERE; | |
334 | } | |
335 | if (info->is_ampere) { | |
336 | analog->meaning->mq = SR_MQ_CURRENT; | |
337 | analog->meaning->unit = SR_UNIT_AMPERE; | |
338 | } | |
339 | if (info->is_frequency) { | |
340 | analog->meaning->mq = SR_MQ_FREQUENCY; | |
341 | analog->meaning->unit = SR_UNIT_HERTZ; | |
342 | } | |
343 | if (info->is_duty_cycle) { | |
344 | analog->meaning->mq = SR_MQ_DUTY_CYCLE; | |
345 | analog->meaning->unit = SR_UNIT_PERCENTAGE; | |
346 | } | |
347 | if (info->is_pulse_width) { | |
348 | analog->meaning->mq = SR_MQ_PULSE_WIDTH; | |
349 | analog->meaning->unit = SR_UNIT_SECOND; | |
350 | } | |
351 | if (info->is_pulse_count) { | |
352 | analog->meaning->mq = SR_MQ_COUNT; | |
353 | analog->meaning->unit = SR_UNIT_UNITLESS; | |
354 | } | |
355 | if (info->is_resistance) { | |
356 | analog->meaning->mq = SR_MQ_RESISTANCE; | |
357 | analog->meaning->unit = SR_UNIT_OHM; | |
358 | } | |
359 | if (info->is_capacitance) { | |
360 | analog->meaning->mq = SR_MQ_CAPACITANCE; | |
361 | analog->meaning->unit = SR_UNIT_FARAD; | |
362 | } | |
363 | if (info->is_diode) { | |
364 | analog->meaning->mq = SR_MQ_VOLTAGE; | |
365 | analog->meaning->unit = SR_UNIT_VOLT; | |
366 | } | |
367 | if (info->is_gain) { | |
368 | analog->meaning->mq = SR_MQ_GAIN; | |
369 | analog->meaning->unit = SR_UNIT_DECIBEL_VOLT; | |
370 | } | |
371 | ||
372 | /* Measurement related flags */ | |
373 | if (info->is_ac) | |
374 | analog->meaning->mqflags |= SR_MQFLAG_AC; | |
375 | if (info->is_ac_and_dc) | |
376 | analog->meaning->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_DC; | |
377 | if (info->is_dc) | |
378 | analog->meaning->mqflags |= SR_MQFLAG_DC; | |
379 | if (info->is_diode) | |
380 | analog->meaning->mqflags |= SR_MQFLAG_DIODE; | |
381 | if (info->is_peak_max) | |
382 | analog->meaning->mqflags |= SR_MQFLAG_MAX; | |
383 | if (info->is_peak_min) | |
384 | analog->meaning->mqflags |= SR_MQFLAG_MIN; | |
385 | } | |
386 | ||
387 | /** | |
388 | * Check measurement details for consistency and validity. | |
389 | * | |
390 | * @param[in] info The previously parsed details. | |
391 | * | |
392 | * @return TRUE on success, FALSE otherwise. | |
393 | */ | |
394 | static gboolean flags_valid(const struct asycii_info *info) | |
395 | { | |
396 | int count; | |
397 | ||
398 | /* Have previous checks raised the "invalid" flag? */ | |
399 | if (info->is_invalid) { | |
400 | sr_dbg("Previous parse raised \"invalid\" flag for packet."); | |
401 | return FALSE; | |
402 | } | |
403 | ||
404 | /* Does the packet have more than one multiplier? */ | |
405 | count = 0; | |
406 | count += (info->is_pico) ? 1 : 0; | |
407 | count += (info->is_nano) ? 1 : 0; | |
408 | count += (info->is_micro) ? 1 : 0; | |
409 | count += (info->is_milli) ? 1 : 0; | |
410 | count += (info->is_kilo) ? 1 : 0; | |
411 | count += (info->is_mega) ? 1 : 0; | |
412 | if (count > 1) { | |
413 | sr_dbg("More than one multiplier detected in packet."); | |
414 | return FALSE; | |
415 | } | |
416 | ||
417 | /* Does the packet "measure" more than one type of value? */ | |
418 | count = 0; | |
419 | count += (info->is_volt || info->is_diode) ? 1 : 0; | |
420 | count += (info->is_volt_ampere) ? 1 : 0; | |
421 | count += (info->is_ampere) ? 1 : 0; | |
422 | count += (info->is_gain) ? 1 : 0; | |
423 | count += (info->is_resistance) ? 1 : 0; | |
424 | count += (info->is_capacitance) ? 1 : 0; | |
425 | count += (info->is_frequency) ? 1 : 0; | |
426 | count += (info->is_duty_cycle) ? 1 : 0; | |
427 | count += (info->is_pulse_width) ? 1 : 0; | |
428 | count += (info->is_pulse_count) ? 1 : 0; | |
429 | if (count > 1) { | |
430 | sr_dbg("More than one measurement type detected in packet."); | |
431 | return FALSE; | |
432 | } | |
433 | ||
434 | /* Are conflicting AC and DC flags set? */ | |
435 | count = 0; | |
436 | count += (info->is_ac) ? 1 : 0; | |
437 | count += (info->is_ac_and_dc) ? 1 : 0; | |
438 | count += (info->is_dc) ? 1 : 0; | |
439 | if (count > 1) { | |
440 | sr_dbg("Conflicting AC and DC flags detected in packet."); | |
441 | return FALSE; | |
442 | } | |
443 | ||
444 | return TRUE; | |
445 | } | |
446 | ||
447 | #ifdef HAVE_LIBSERIALPORT | |
448 | /** | |
449 | * Arrange for the reception of another measurement from the DMM. | |
450 | * | |
451 | * This routine is unused in the currently implemented PRINT mode, | |
452 | * where the meter sends measurements to the PC in pre-set intervals, | |
453 | * without the PC's intervention. | |
454 | * | |
455 | * @param[in] serial The serial connection. | |
456 | * | |
457 | * @private | |
458 | */ | |
459 | SR_PRIV int sr_asycii_packet_request(struct sr_serial_dev_inst *serial) | |
460 | { | |
461 | /* | |
462 | * The current implementation assumes that the user pressed | |
463 | * the PRINT button. It has no support to query/trigger packet | |
464 | * reception from the meter. | |
465 | */ | |
466 | (void)serial; | |
467 | sr_spew("NOT requesting DMM packet."); | |
468 | return SR_OK; | |
469 | } | |
470 | #endif | |
471 | ||
472 | /** | |
473 | * Check whether a received frame is valid. | |
474 | * | |
475 | * @param[in] buf The text buffer with received data. | |
476 | * | |
477 | * @return TRUE upon success, FALSE otherwise. | |
478 | */ | |
479 | SR_PRIV gboolean sr_asycii_packet_valid(const uint8_t *buf) | |
480 | { | |
481 | struct asycii_info info; | |
482 | ||
483 | /* First check whether we are in sync with the packet stream. */ | |
484 | if (buf[15] != '\r') | |
485 | return FALSE; | |
486 | ||
487 | /* Have the received packet content parsed. */ | |
488 | memset(&info, 0x00, sizeof(info)); | |
489 | parse_flags((const char *)buf, &info); | |
490 | if (!flags_valid(&info)) | |
491 | return FALSE; | |
492 | ||
493 | return TRUE; | |
494 | } | |
495 | ||
496 | /** | |
497 | * Parse a protocol packet. | |
498 | * | |
499 | * @param[in] buf Buffer containing the protocol packet. Must not be NULL. | |
500 | * @param[out] floatval Pointer to a float variable. That variable will | |
501 | * be modified in-place depending on the protocol packet. | |
502 | * Must not be NULL. | |
503 | * @param[out] analog Pointer to a struct sr_datafeed_analog. The struct | |
504 | * will be filled with data according to the protocol packet. | |
505 | * Must not be NULL. | |
506 | * @param[out] info Pointer to a struct asycii_info. The struct will be | |
507 | * filled with data according to the protocol packet. Must | |
508 | * not be NULL. | |
509 | * | |
510 | * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the | |
511 | * 'analog' variable contents are undefined and should not | |
512 | * be used. | |
513 | */ | |
514 | SR_PRIV int sr_asycii_parse(const uint8_t *buf, float *floatval, | |
515 | struct sr_datafeed_analog *analog, void *info) | |
516 | { | |
517 | int ret, exponent; | |
518 | struct asycii_info *info_local; | |
519 | ||
520 | info_local = (struct asycii_info *)info; | |
521 | ||
522 | /* Don't print byte 15. That one contains the carriage return. */ | |
523 | sr_dbg("DMM packet: \"%.15s\"", buf); | |
524 | ||
525 | memset(info_local, 0x00, sizeof(*info_local)); | |
526 | ||
527 | exponent = 0; | |
528 | ret = parse_value((const char *)buf, info_local, floatval, &exponent); | |
529 | if (ret != SR_OK) { | |
530 | sr_dbg("Error parsing value: %d.", ret); | |
531 | return ret; | |
532 | } | |
533 | ||
534 | parse_flags((const char *)buf, info_local); | |
535 | handle_flags(analog, floatval, &exponent, info_local); | |
536 | ||
537 | analog->encoding->digits = -exponent; | |
538 | analog->spec->spec_digits = -exponent; | |
539 | ||
540 | return SR_OK; | |
541 | } |