libsigrok  0.5.0
sigrok hardware access and backend library
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analog.c
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1 /*
2  * This file is part of the libsigrok project.
3  *
4  * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
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 3 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, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <config.h>
21 #include <stdio.h>
22 #include <stdint.h>
23 #include <string.h>
24 #include <ctype.h>
25 #include <math.h>
26 #include <libsigrok/libsigrok.h>
27 #include "libsigrok-internal.h"
28 
29 /** @cond PRIVATE */
30 #define LOG_PREFIX "analog"
31 /** @endcond */
32 
33 /**
34  * @file
35  *
36  * Handling and converting analog data.
37  */
38 
39 /**
40  * @defgroup grp_analog Analog data handling
41  *
42  * Handling and converting analog data.
43  *
44  * @{
45  */
46 
47 struct unit_mq_string {
48  uint64_t value;
49  const char *str;
50 };
51 
52 /* Please use the same order as in enum sr_unit (libsigrok.h). */
53 static struct unit_mq_string unit_strings[] = {
54  { SR_UNIT_VOLT, "V" },
55  { SR_UNIT_AMPERE, "A" },
56  { SR_UNIT_OHM, "\xe2\x84\xa6" },
57  { SR_UNIT_FARAD, "F" },
58  { SR_UNIT_KELVIN, "K" },
59  { SR_UNIT_CELSIUS, "\xc2\xb0""C" },
60  { SR_UNIT_FAHRENHEIT, "\xc2\xb0""F" },
61  { SR_UNIT_HERTZ, "Hz" },
62  { SR_UNIT_PERCENTAGE, "%" },
63  { SR_UNIT_BOOLEAN, "" },
64  { SR_UNIT_SECOND, "s" },
65  { SR_UNIT_SIEMENS, "S" },
66  { SR_UNIT_DECIBEL_MW, "dBm" },
67  { SR_UNIT_DECIBEL_VOLT, "dBV" },
68  { SR_UNIT_UNITLESS, "" },
69  { SR_UNIT_DECIBEL_SPL, "dB" },
70  { SR_UNIT_CONCENTRATION, "ppm" },
72  { SR_UNIT_VOLT_AMPERE, "VA" },
73  { SR_UNIT_WATT, "W" },
74  { SR_UNIT_WATT_HOUR, "Wh" },
75  { SR_UNIT_METER_SECOND, "m/s" },
76  { SR_UNIT_HECTOPASCAL, "hPa" },
77  { SR_UNIT_HUMIDITY_293K, "%rF" },
78  { SR_UNIT_DEGREE, "\xc2\xb0" },
79  { SR_UNIT_HENRY, "H" },
80  { SR_UNIT_GRAM, "g" },
81  { SR_UNIT_CARAT, "ct" },
82  { SR_UNIT_OUNCE, "oz" },
83  { SR_UNIT_TROY_OUNCE, "oz t" },
84  { SR_UNIT_POUND, "lb" },
85  { SR_UNIT_PENNYWEIGHT, "dwt" },
86  { SR_UNIT_GRAIN, "gr" },
87  { SR_UNIT_TAEL, "tael" },
88  { SR_UNIT_MOMME, "momme" },
89  { SR_UNIT_TOLA, "tola" },
90  { SR_UNIT_PIECE, "pcs" },
91  ALL_ZERO
92 };
93 
94 /* Please use the same order as in enum sr_mqflag (libsigrok.h). */
95 static struct unit_mq_string mq_strings[] = {
96  { SR_MQFLAG_AC, " AC" },
97  { SR_MQFLAG_DC, " DC" },
98  { SR_MQFLAG_RMS, " RMS" },
99  { SR_MQFLAG_DIODE, " DIODE" },
100  { SR_MQFLAG_HOLD, " HOLD" },
101  { SR_MQFLAG_MAX, " MAX" },
102  { SR_MQFLAG_MIN, " MIN" },
103  { SR_MQFLAG_AUTORANGE, " AUTO" },
104  { SR_MQFLAG_RELATIVE, " REL" },
105  { SR_MQFLAG_SPL_FREQ_WEIGHT_A, "(A)" },
106  { SR_MQFLAG_SPL_FREQ_WEIGHT_C, "(C)" },
107  { SR_MQFLAG_SPL_FREQ_WEIGHT_Z, "(Z)" },
108  { SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT, "(SPL)" },
109  { SR_MQFLAG_SPL_TIME_WEIGHT_S, " S" },
110  { SR_MQFLAG_SPL_TIME_WEIGHT_F, " F" },
111  { SR_MQFLAG_SPL_LAT, " LAT" },
112  /* Not a standard function for SLMs, so this is a made-up notation. */
113  { SR_MQFLAG_SPL_PCT_OVER_ALARM, "%oA" },
114  { SR_MQFLAG_DURATION, " DURATION" },
115  { SR_MQFLAG_AVG, " AVG" },
116  { SR_MQFLAG_REFERENCE, " REF" },
117  { SR_MQFLAG_UNSTABLE, " UNSTABLE" },
118  { SR_MQFLAG_FOUR_WIRE, " 4-WIRE" },
119  ALL_ZERO
120 };
121 
122 /** @private */
123 SR_PRIV int sr_analog_init(struct sr_datafeed_analog *analog,
124  struct sr_analog_encoding *encoding,
125  struct sr_analog_meaning *meaning,
126  struct sr_analog_spec *spec,
127  int digits)
128 {
129  memset(analog, 0, sizeof(*analog));
130  memset(encoding, 0, sizeof(*encoding));
131  memset(meaning, 0, sizeof(*meaning));
132  memset(spec, 0, sizeof(*spec));
133 
134  analog->encoding = encoding;
135  analog->meaning = meaning;
136  analog->spec = spec;
137 
138  encoding->unitsize = sizeof(float);
139  encoding->is_float = TRUE;
140 #ifdef WORDS_BIGENDIAN
141  encoding->is_bigendian = TRUE;
142 #else
143  encoding->is_bigendian = FALSE;
144 #endif
145  encoding->digits = digits;
146  encoding->is_digits_decimal = TRUE;
147  encoding->scale.p = 1;
148  encoding->scale.q = 1;
149  encoding->offset.p = 0;
150  encoding->offset.q = 1;
151 
152  spec->spec_digits = digits;
153 
154  return SR_OK;
155 }
156 
157 /**
158  * Convert an analog datafeed payload to an array of floats.
159  *
160  * Sufficient memory for outbuf must have been pre-allocated by the caller,
161  * who is also responsible for freeing it when no longer needed.
162  *
163  * @param[in] analog The analog payload to convert. Must not be NULL.
164  * analog->data, analog->meaning, and analog->encoding
165  * must not be NULL.
166  * @param[out] outbuf Memory where to store the result. Must not be NULL.
167  *
168  * @retval SR_OK Success.
169  * @retval SR_ERR Unsupported encoding.
170  * @retval SR_ERR_ARG Invalid argument.
171  *
172  * @since 0.4.0
173  */
175  float *outbuf)
176 {
177  float offset;
178  unsigned int b, i, count;
179  gboolean bigendian;
180 
181  if (!analog || !(analog->data) || !(analog->meaning)
182  || !(analog->encoding) || !outbuf)
183  return SR_ERR_ARG;
184 
185  count = analog->num_samples * g_slist_length(analog->meaning->channels);
186 
187 #ifdef WORDS_BIGENDIAN
188  bigendian = TRUE;
189 #else
190  bigendian = FALSE;
191 #endif
192 
193  if (!analog->encoding->is_float) {
194  float offset = analog->encoding->offset.p / (float)analog->encoding->offset.q;
195  float scale = analog->encoding->scale.p / (float)analog->encoding->scale.q;
196  gboolean is_signed = analog->encoding->is_signed;
197  gboolean is_bigendian = analog->encoding->is_bigendian;
198  int8_t *data8 = (int8_t *)(analog->data);
199  int16_t *data16 = (int16_t *)(analog->data);
200  int32_t *data32 = (int32_t *)(analog->data);
201 
202  switch (analog->encoding->unitsize) {
203  case 1:
204  if (is_signed) {
205  for (unsigned int i = 0; i < count; i++) {
206  outbuf[i] = scale * data8[i];
207  outbuf[i] += offset;
208  }
209  } else {
210  for (unsigned int i = 0; i < count; i++) {
211  outbuf[i] = scale * R8(data8 + i);
212  outbuf[i] += offset;
213  }
214  }
215  break;
216  case 2:
217  if (is_signed && is_bigendian) {
218  for (unsigned int i = 0; i < count; i++) {
219  outbuf[i] = scale * RB16S(&data16[i]);
220  outbuf[i] += offset;
221  }
222  } else if (is_bigendian) {
223  for (unsigned int i = 0; i < count; i++) {
224  outbuf[i] = scale * RB16(&data16[i]);
225  outbuf[i] += offset;
226  }
227  } else if (is_signed) {
228  for (unsigned int i = 0; i < count; i++) {
229  outbuf[i] = scale * RL16S(&data16[i]);
230  outbuf[i] += offset;
231  }
232  } else {
233  for (unsigned int i = 0; i < count; i++) {
234  outbuf[i] = scale * RL16(&data16[i]);
235  outbuf[i] += offset;
236  }
237  }
238  break;
239  case 4:
240  if (is_signed && is_bigendian) {
241  for (unsigned int i = 0; i < count; i++) {
242  outbuf[i] = scale * RB32S(&data32[i]);
243  outbuf[i] += offset;
244  }
245  } else if (is_bigendian) {
246  for (unsigned int i = 0; i < count; i++) {
247  outbuf[i] = scale * RB32(&data32[i]);
248  outbuf[i] += offset;
249  }
250  } else if (is_signed) {
251  for (unsigned int i = 0; i < count; i++) {
252  outbuf[i] = scale * RL32S(&data32[i]);
253  outbuf[i] += offset;
254  }
255  } else {
256  for (unsigned int i = 0; i < count; i++) {
257  outbuf[i] = scale * RL32(&data32[i]);
258  outbuf[i] += offset;
259  }
260  }
261  break;
262  default:
263  sr_err("Unsupported unit size '%d' for analog-to-float"
264  " conversion.", analog->encoding->unitsize);
265  return SR_ERR;
266  }
267  return SR_OK;
268  }
269 
270  if (analog->encoding->unitsize == sizeof(float)
271  && analog->encoding->is_bigendian == bigendian
272  && analog->encoding->scale.p == 1
273  && analog->encoding->scale.q == 1
274  && analog->encoding->offset.p / (float)analog->encoding->offset.q == 0) {
275  /* The data is already in the right format. */
276  memcpy(outbuf, analog->data, count * sizeof(float));
277  } else {
278  for (i = 0; i < count; i += analog->encoding->unitsize) {
279  for (b = 0; b < analog->encoding->unitsize; b++) {
280  if (analog->encoding->is_bigendian == bigendian)
281  ((uint8_t *)outbuf)[i + b] =
282  ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
283  else
284  ((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] =
285  ((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
286  }
287  if (analog->encoding->scale.p != 1
288  || analog->encoding->scale.q != 1)
289  outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q;
290  offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q);
291  outbuf[i] += offset;
292  }
293  }
294 
295  return SR_OK;
296 }
297 
298 /**
299  * Scale a float value to the appropriate SI prefix.
300  *
301  * @param[in,out] value The float value to convert to appropriate SI prefix.
302  * @param[in,out] digits The number of significant decimal digits in value.
303  *
304  * @return The SI prefix to which value was scaled, as a printable string.
305  *
306  * @since 0.5.0
307  */
308 SR_API const char *sr_analog_si_prefix(float *value, int *digits)
309 {
310 /** @cond PRIVATE */
311 #define NEG_PREFIX_COUNT 5 /* number of prefixes below unity */
312 #define POS_PREFIX_COUNT (int)(ARRAY_SIZE(prefixes) - NEG_PREFIX_COUNT - 1)
313 /** @endcond */
314  static const char *prefixes[] = { "f", "p", "n", "µ", "m", "", "k", "M", "G", "T" };
315 
316  if (!value || !digits || isnan(*value))
317  return prefixes[NEG_PREFIX_COUNT];
318 
319  float logval = log10f(fabsf(*value));
320  int prefix = (logval / 3) - (logval < 1);
321 
322  if (prefix < -NEG_PREFIX_COUNT)
323  prefix = -NEG_PREFIX_COUNT;
324  if (3 * prefix < -*digits)
325  prefix = (-*digits + 2 * (*digits < 0)) / 3;
326  if (prefix > POS_PREFIX_COUNT)
327  prefix = POS_PREFIX_COUNT;
328 
329  *value *= powf(10, -3 * prefix);
330  *digits += 3 * prefix;
331 
332  return prefixes[prefix + NEG_PREFIX_COUNT];
333 }
334 
335 /**
336  * Check if a unit "accepts" an SI prefix.
337  *
338  * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or
339  * SR_UNIT_PERCENTAGE are not.
340  *
341  * @param[in] unit The unit to check for SI prefix "friendliness".
342  *
343  * @return TRUE if the unit "accept" an SI prefix.
344  *
345  * @since 0.5.0
346  */
348 {
349  static const enum sr_unit prefix_friendly_units[] = {
350  SR_UNIT_VOLT,
352  SR_UNIT_OHM,
359  SR_UNIT_WATT,
364  };
365  unsigned int i;
366 
367  for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++)
368  if (unit == prefix_friendly_units[i])
369  break;
370 
371  if (unit != prefix_friendly_units[i])
372  return FALSE;
373 
374  return TRUE;
375 }
376 
377 /**
378  * Convert the unit/MQ/MQ flags in the analog struct to a string.
379  *
380  * The string is allocated by the function and must be freed by the caller
381  * after use by calling g_free().
382  *
383  * @param[in] analog Struct containing the unit, MQ and MQ flags.
384  * Must not be NULL. analog->meaning must not be NULL.
385  * @param[out] result Pointer to store result. Must not be NULL.
386  *
387  * @retval SR_OK Success.
388  * @retval SR_ERR_ARG Invalid argument.
389  *
390  * @since 0.4.0
391  */
393  char **result)
394 {
395  int i;
396  GString *buf;
397 
398  if (!analog || !(analog->meaning) || !result)
399  return SR_ERR_ARG;
400 
401  buf = g_string_new(NULL);
402 
403  for (i = 0; unit_strings[i].value; i++) {
404  if (analog->meaning->unit == unit_strings[i].value) {
405  g_string_assign(buf, unit_strings[i].str);
406  break;
407  }
408  }
409 
410  /* More than one MQ flag may apply. */
411  for (i = 0; mq_strings[i].value; i++)
412  if (analog->meaning->mqflags & mq_strings[i].value)
413  g_string_append(buf, mq_strings[i].str);
414 
415  *result = buf->str;
416  g_string_free(buf, FALSE);
417 
418  return SR_OK;
419 }
420 
421 /**
422  * Set sr_rational r to the given value.
423  *
424  * @param[out] r Rational number struct to set. Must not be NULL.
425  * @param[in] p Numerator.
426  * @param[in] q Denominator.
427  *
428  * @since 0.4.0
429  */
430 SR_API void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
431 {
432  if (!r)
433  return;
434 
435  r->p = p;
436  r->q = q;
437 }
438 
439 #ifndef HAVE___INT128_T
440 struct sr_int128_t {
441  int64_t high;
442  uint64_t low;
443 };
444 
445 struct sr_uint128_t {
446  uint64_t high;
447  uint64_t low;
448 };
449 
450 static void mult_int64(struct sr_int128_t *res, const int64_t a,
451  const int64_t b)
452 {
453  uint64_t t1, t2, t3, t4;
454 
455  t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
456  t2 = (UINT32_MAX & a) * (b >> 32);
457  t3 = (a >> 32) * (UINT32_MAX & b);
458  t4 = (a >> 32) * (b >> 32);
459 
460  res->low = t1 + (t2 << 32) + (t3 << 32);
461  res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
462  res->high >>= 32;
463  res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
464 }
465 
466 static void mult_uint64(struct sr_uint128_t *res, const uint64_t a,
467  const uint64_t b)
468 {
469  uint64_t t1, t2, t3, t4;
470 
471  // (x1 + x2) * (y1 + y2) = x1*y1 + x1*y2 + x2*y1 + x2*y2
472  t1 = (UINT32_MAX & a) * (UINT32_MAX & b);
473  t2 = (UINT32_MAX & a) * (b >> 32);
474  t3 = (a >> 32) * (UINT32_MAX & b);
475  t4 = (a >> 32) * (b >> 32);
476 
477  res->low = t1 + (t2 << 32) + (t3 << 32);
478  res->high = (t1 >> 32) + (uint64_t)((uint32_t)(t2)) + (uint64_t)((uint32_t)(t3));
479  res->high >>= 32;
480  res->high += ((int64_t)t2 >> 32) + ((int64_t)t3 >> 32) + t4;
481 }
482 #endif
483 
484 /**
485  * Compare two sr_rational for equality.
486  *
487  * The values are compared for numerical equality, i.e. 2/10 == 1/5.
488  *
489  * @param[in] a First value.
490  * @param[in] b Second value.
491  *
492  * @retval 1 if both values are equal.
493  * @retval 0 Otherwise.
494  *
495  * @since 0.5.0
496  */
497 SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b)
498 {
499 #ifdef HAVE___INT128_T
500  __int128_t m1, m2;
501 
502  /* p1/q1 = p2/q2 <=> p1*q2 = p2*q1 */
503  m1 = ((__int128_t)(b->p)) * ((__uint128_t)a->q);
504  m2 = ((__int128_t)(a->p)) * ((__uint128_t)b->q);
505 
506  return (m1 == m2);
507 
508 #else
509  struct sr_int128_t m1, m2;
510 
511  mult_int64(&m1, a->q, b->p);
512  mult_int64(&m2, a->p, b->q);
513 
514  return (m1.high == m2.high) && (m1.low == m2.low);
515 #endif
516 }
517 
518 /**
519  * Multiply two sr_rational.
520  *
521  * The resulting nominator/denominator are reduced if the result would not fit
522  * otherwise. If the resulting nominator/denominator are relatively prime,
523  * this may not be possible.
524  *
525  * It is safe to use the same variable for result and input values.
526  *
527  * @param[in] a First value.
528  * @param[in] b Second value.
529  * @param[out] res Result.
530  *
531  * @retval SR_OK Success.
532  * @retval SR_ERR_ARG Resulting value too large.
533  *
534  * @since 0.5.0
535  */
536 SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a,
537  const struct sr_rational *b)
538 {
539 #ifdef HAVE___INT128_T
540  __int128_t p;
541  __uint128_t q;
542 
543  p = (__int128_t)(a->p) * (__int128_t)(b->p);
544  q = (__uint128_t)(a->q) * (__uint128_t)(b->q);
545 
546  if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) {
547  while (!((p & 1) || (q & 1))) {
548  p /= 2;
549  q /= 2;
550  }
551  }
552 
553  if ((p > INT64_MAX) || (p < INT64_MIN) || (q > UINT64_MAX)) {
554  // TODO: determine gcd to do further reduction
555  return SR_ERR_ARG;
556  }
557 
558  res->p = (int64_t)(p);
559  res->q = (uint64_t)(q);
560 
561  return SR_OK;
562 
563 #else
564  struct sr_int128_t p;
565  struct sr_uint128_t q;
566 
567  mult_int64(&p, a->p, b->p);
568  mult_uint64(&q, a->q, b->q);
569 
570  while (!(p.low & 1) && !(q.low & 1)) {
571  p.low /= 2;
572  if (p.high & 1)
573  p.low |= (1ll << 63);
574  p.high >>= 1;
575  q.low /= 2;
576  if (q.high & 1)
577  q.low |= (1ll << 63);
578  q.high >>= 1;
579  }
580 
581  if (q.high)
582  return SR_ERR_ARG;
583  if ((p.high >= 0) && (p.low > INT64_MAX))
584  return SR_ERR_ARG;
585  if (p.high < -1)
586  return SR_ERR_ARG;
587 
588  res->p = (int64_t)p.low;
589  res->q = q.low;
590 
591  return SR_OK;
592 #endif
593 }
594 
595 /**
596  * Divide rational a by rational b.
597  *
598  * The resulting nominator/denominator are reduced if the result would not fit
599  * otherwise. If the resulting nominator/denominator are relatively prime,
600  * this may not be possible.
601  *
602  * It is safe to use the same variable for result and input values.
603  *
604  * @param[in] num Numerator.
605  * @param[in] div Divisor.
606  * @param[out] res Result.
607  *
608  * @retval SR_OK Success.
609  * @retval SR_ERR_ARG Division by zero.
610  * @retval SR_ERR_ARG Denominator of divisor too large.
611  * @retval SR_ERR_ARG Resulting value too large.
612  *
613  * @since 0.5.0
614  */
615 SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num,
616  const struct sr_rational *div)
617 {
618  struct sr_rational t;
619 
620  if (div->q > INT64_MAX)
621  return SR_ERR_ARG;
622  if (div->p == 0)
623  return SR_ERR_ARG;
624 
625  if (div->p > 0) {
626  t.p = div->q;
627  t.q = div->p;
628  } else {
629  t.p = -div->q;
630  t.q = -div->p;
631  }
632 
633  return sr_rational_mult(res, num, &t);
634 }
635 
636 /** @} */
Generic/unspecified error.
Definition: libsigrok.h:68
Time is duration (as opposed to epoch, ...).
Definition: libsigrok.h:379
Reference value shown.
Definition: libsigrok.h:383
Sound pressure level is not weighted in the frequency domain, albeit without standards-defined low an...
Definition: libsigrok.h:365
int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b)
Compare two sr_rational for equality.
Definition: analog.c:497
Sound pressure level is A-weighted in the frequency domain, according to IEC 61672:2003.
Definition: libsigrok.h:356
const char * sr_analog_si_prefix(float *value, int *digits)
Scale a float value to the appropriate SI prefix.
Definition: analog.c:308
Measurement is four wire (e.g.
Definition: libsigrok.h:387
Degrees Fahrenheit (temperature).
Definition: libsigrok.h:255
void sr_rational_set(struct sr_rational *r, int64_t p, uint64_t q)
Set sr_rational r to the given value.
Definition: analog.c:430
This is a true RMS measurement.
Definition: libsigrok.h:341
Normalized (0 to 1) concentration of a substance or compound with 0 representing a concentration of 0...
Definition: libsigrok.h:286
Plane angle in 1/360th of a full circle.
Definition: libsigrok.h:302
Percent value.
Definition: libsigrok.h:259
Sound pressure level measurement is S-weighted (1s) in the time domain.
Definition: libsigrok.h:368
Ampere (current).
Definition: libsigrok.h:245
Unit of conductance, the inverse of resistance.
Definition: libsigrok.h:265
Sound pressure level measurement is F-weighted (125ms) in the time domain.
Definition: libsigrok.h:371
No error.
Definition: libsigrok.h:67
Degrees Celsius (temperature).
Definition: libsigrok.h:253
GSList * channels
Definition: libsigrok.h:528
Mass in pound [lb].
Definition: libsigrok.h:314
gboolean is_signed
Definition: libsigrok.h:510
Mass in momme.
Definition: libsigrok.h:322
The public libsigrok header file to be used by frontends.
An absolute measurement of power, in decibels, referenced to 1 milliwatt (dBm).
Definition: libsigrok.h:270
Sound pressure level is time-averaged (LAT), also known as Equivalent Continuous A-weighted Sound Lev...
Definition: libsigrok.h:374
Device is in autoranging mode.
Definition: libsigrok.h:351
Volt.
Definition: libsigrok.h:243
Pieces (number of items).
Definition: libsigrok.h:326
Sound pressure level is C-weighted in the frequency domain, according to IEC 61672:2003.
Definition: libsigrok.h:359
struct sr_rational scale
Definition: libsigrok.h:520
Mass in tael (variants: Hong Kong, Singapore/Malaysia, Taiwan)
Definition: libsigrok.h:320
struct sr_analog_encoding * encoding
Definition: libsigrok.h:503
Device is in "min" mode, only updating upon a new min value.
Definition: libsigrok.h:349
Consumption [Wh].
Definition: libsigrok.h:294
Sound pressure level represented as a percentage of measurements that were over a preset alarm level...
Definition: libsigrok.h:377
Mass in tola.
Definition: libsigrok.h:324
Voltage measurement is alternating current (AC).
Definition: libsigrok.h:337
int sr_analog_to_float(const struct sr_datafeed_analog *analog, float *outbuf)
Convert an analog datafeed payload to an array of floats.
Definition: analog.c:174
Farad (capacity).
Definition: libsigrok.h:249
Device is in "hold" mode (repeating the last measurement).
Definition: libsigrok.h:345
gboolean sr_analog_si_prefix_friendly(enum sr_unit unit)
Check if a unit "accepts" an SI prefix.
Definition: analog.c:347
int8_t spec_digits
Number of significant digits after the decimal point if positive, or number of non-significant digits...
Definition: libsigrok.h:538
enum sr_unit unit
Definition: libsigrok.h:526
Ohm (resistance).
Definition: libsigrok.h:247
sr_unit
Unit of measured quantity, sr_analog_meaning.unit.
Definition: libsigrok.h:241
struct sr_analog_meaning * meaning
Definition: libsigrok.h:504
Hertz (frequency, 1/s, [Hz]).
Definition: libsigrok.h:257
Boolean value.
Definition: libsigrok.h:261
Kelvin (temperature).
Definition: libsigrok.h:251
#define SR_PRIV
Definition: libsigrok.h:128
Mass in carat [ct].
Definition: libsigrok.h:308
gboolean is_digits_decimal
Definition: libsigrok.h:519
Device is in "avg" mode, averaging upon each new value.
Definition: libsigrok.h:381
Voltage measurement is direct current (DC).
Definition: libsigrok.h:339
Pressure in hectopascal.
Definition: libsigrok.h:298
struct sr_analog_spec * spec
Definition: libsigrok.h:505
uint64_t q
Denominator of the rational number.
Definition: libsigrok.h:472
int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a, const struct sr_rational *b)
Multiply two sr_rational.
Definition: analog.c:536
Revolutions per minute.
Definition: libsigrok.h:288
int sr_rational_div(struct sr_rational *res, const struct sr_rational *num, const struct sr_rational *div)
Divide rational a by rational b.
Definition: analog.c:615
Mass in troy ounce [oz t].
Definition: libsigrok.h:312
Apparent power [VA].
Definition: libsigrok.h:290
int sr_analog_unit_to_string(const struct sr_datafeed_analog *analog, char **result)
Convert the unit/MQ/MQ flags in the analog struct to a string.
Definition: analog.c:392
Mass in grain [gr].
Definition: libsigrok.h:318
Henry (inductance).
Definition: libsigrok.h:304
int64_t p
Numerator of the rational number.
Definition: libsigrok.h:470
Voltage in decibel, referenced to 1 volt (dBV).
Definition: libsigrok.h:272
Analog datafeed payload for type SR_DF_ANALOG.
Definition: libsigrok.h:500
Function argument error.
Definition: libsigrok.h:70
struct sr_rational offset
Definition: libsigrok.h:521
Sound pressure level is Z-weighted (i.e.
Definition: libsigrok.h:362
Real power [W].
Definition: libsigrok.h:292
enum sr_mqflag mqflags
Definition: libsigrok.h:527
Relative humidity assuming air temperature of 293 Kelvin (rF).
Definition: libsigrok.h:300
Value is voltage drop across a diode, or NAN.
Definition: libsigrok.h:343
Sound pressure level, in decibels, relative to 20 micropascals.
Definition: libsigrok.h:280
Mass in pennyweight [dwt].
Definition: libsigrok.h:316
Device is in "max" mode, only updating upon a new max value.
Definition: libsigrok.h:347
Device is in relative mode.
Definition: libsigrok.h:353
uint32_t num_samples
Definition: libsigrok.h:502
Time in seconds.
Definition: libsigrok.h:263
gboolean is_float
Definition: libsigrok.h:511
Wind speed in meters per second.
Definition: libsigrok.h:296
gboolean is_bigendian
Definition: libsigrok.h:512
int8_t digits
Number of significant digits after the decimal point if positive, or number of non-significant digits...
Definition: libsigrok.h:518
Mass in ounce [oz].
Definition: libsigrok.h:310
Measurements that intrinsically do not have units attached, such as ratios, gains, etc.
Definition: libsigrok.h:278
#define SR_API
Definition: libsigrok.h:121
Unstable value (hasn't settled yet).
Definition: libsigrok.h:385
Mass in gram [g].
Definition: libsigrok.h:306