2 * This file is part of the libsigrok project.
4 * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
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.
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.
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/>.
23 * Metex 14-bytes ASCII protocol parser.
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.
29 * It does _not_ work for all Metex DMMs, some use a quite different protocol.
38 #include <libsigrok/libsigrok.h>
39 #include "libsigrok-internal.h"
41 #define LOG_PREFIX "metex14"
43 /** Parse value from buf, byte 2-8. */
44 static int parse_value(const uint8_t *buf, struct metex14_info *info,
45 float *result, int *exponent)
47 int i, is_ol, cnt, dot_pos;
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];
57 /* Bytes 5-7: Over limit (various forms) */
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;
68 sr_spew("Over limit.");
74 if (!strcmp((const char *)&valstr, "READY") ||
75 !strcmp((const char *)&valstr, "FLOAT")) {
77 info->is_logic = TRUE;
78 } else if (!strcmp((const char *)&valstr, "Hi")) {
80 info->is_logic = TRUE;
81 } else if (!strcmp((const char *)&valstr, "Lo")) {
83 info->is_logic = TRUE;
88 /* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
89 sr_atof_ascii((const char *)&valstr, result);
91 dot_pos = strcspn(valstr, ".");
93 *exponent = -(cnt - dot_pos - 1);
97 sr_spew("The display value is %f.", *result);
102 static void parse_flags(const char *buf, struct metex14_info *info)
108 /* Bytes 0-1: Measurement mode AC, DC */
109 info->is_ac = !strncmp(buf, "AC", 2);
110 info->is_dc = !strncmp(buf, "DC", 2);
112 /* Bytes 2-8: See parse_value(). */
114 /* Strip all spaces from bytes 9-12. */
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];
121 /* Bytes 9-12: Unit */
122 u = (const char *)&unit;
123 if (!g_ascii_strcasecmp(u, "A"))
124 info->is_ampere = TRUE;
125 else if (!g_ascii_strcasecmp(u, "mA"))
126 info->is_milli = info->is_ampere = TRUE;
127 else if (!g_ascii_strcasecmp(u, "uA"))
128 info->is_micro = info->is_ampere = TRUE;
129 else if (!g_ascii_strcasecmp(u, "V"))
130 info->is_volt = TRUE;
131 else if (!g_ascii_strcasecmp(u, "mV"))
132 info->is_milli = info->is_volt = TRUE;
133 else if (!g_ascii_strcasecmp(u, "Ohm"))
135 else if (!g_ascii_strcasecmp(u, "KOhm"))
136 info->is_kilo = info->is_ohm = TRUE;
137 else if (!g_ascii_strcasecmp(u, "MOhm"))
138 info->is_mega = info->is_ohm = TRUE;
139 else if (!g_ascii_strcasecmp(u, "pF"))
140 info->is_pico = info->is_farad = TRUE;
141 else if (!g_ascii_strcasecmp(u, "nF"))
142 info->is_nano = info->is_farad = TRUE;
143 else if (!g_ascii_strcasecmp(u, "uF"))
144 info->is_micro = info->is_farad = TRUE;
145 else if (!g_ascii_strcasecmp(u, "KHz"))
146 info->is_kilo = info->is_hertz = TRUE;
147 else if (!g_ascii_strcasecmp(u, "C"))
148 info->is_celsius = TRUE;
149 else if (!g_ascii_strcasecmp(u, "F"))
150 info->is_fahrenheit = TRUE;
151 else if (!g_ascii_strcasecmp(u, "DB"))
152 info->is_decibel = TRUE;
153 else if (!g_ascii_strcasecmp(u, "dBm"))
154 info->is_decibel_mw = TRUE;
155 else if (!g_ascii_strcasecmp(u, "W"))
156 info->is_watt = TRUE;
157 else if (!g_ascii_strcasecmp(u, ""))
158 info->is_unitless = TRUE;
160 /* Bytes 0-1: Measurement mode, except AC/DC */
161 info->is_resistance = !strncmp(buf, "OH", 2) ||
162 (!strncmp(buf, " ", 2) && info->is_ohm);
163 info->is_capacity = !strncmp(buf, "CA", 2) ||
164 (!strncmp(buf, " ", 2) && info->is_farad);
165 info->is_temperature = !strncmp(buf, "TE", 2) ||
166 info->is_celsius || info->is_fahrenheit;
167 info->is_diode = !strncmp(buf, "DI", 2) ||
168 (!strncmp(buf, " ", 2) && info->is_volt && info->is_milli);
169 info->is_frequency = !strncmp(buf, "FR", 2) ||
170 (!strncmp(buf, " ", 2) && info->is_hertz);
171 info->is_gain = !strncmp(buf, "DB", 2) && info->is_decibel;
172 info->is_power = (!strncmp(buf, "dB", 2) && info->is_decibel_mw) ||
173 ((!strncmp(buf, "WT", 2) && info->is_watt));
174 info->is_hfe = !strncmp(buf, "HF", 2) ||
175 (!strncmp(buf, " ", 2) && !info->is_volt && !info->is_ohm &&
176 !info->is_logic && !info->is_farad && !info->is_hertz);
177 info->is_min = !strncmp(buf, "MN", 2);
178 info->is_max = !strncmp(buf, "MX", 2);
179 info->is_avg = !strncmp(buf, "AG", 2);
183 * - Protocol doesn't distinguish "resistance" from "beep" mode.
184 * - "DB" shows the logarithmic ratio of input voltage to a
185 * pre-stored (user-changeable) value in the DMM.
188 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
191 static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
192 int *exponent, const struct metex14_info *info)
212 *floatval *= powf(10, factor);
214 /* Measurement modes */
216 analog->meaning->mq = SR_MQ_VOLTAGE;
217 analog->meaning->unit = SR_UNIT_VOLT;
219 if (info->is_ampere) {
220 analog->meaning->mq = SR_MQ_CURRENT;
221 analog->meaning->unit = SR_UNIT_AMPERE;
224 analog->meaning->mq = SR_MQ_RESISTANCE;
225 analog->meaning->unit = SR_UNIT_OHM;
227 if (info->is_hertz) {
228 analog->meaning->mq = SR_MQ_FREQUENCY;
229 analog->meaning->unit = SR_UNIT_HERTZ;
231 if (info->is_farad) {
232 analog->meaning->mq = SR_MQ_CAPACITANCE;
233 analog->meaning->unit = SR_UNIT_FARAD;
235 if (info->is_temperature) {
236 analog->meaning->mq = SR_MQ_TEMPERATURE;
237 if (info->is_celsius)
238 analog->meaning->unit = SR_UNIT_CELSIUS;
239 else if (info->is_fahrenheit)
240 analog->meaning->unit = SR_UNIT_FAHRENHEIT;
242 analog->meaning->unit = SR_UNIT_UNITLESS;
244 if (info->is_diode) {
245 analog->meaning->mq = SR_MQ_VOLTAGE;
246 analog->meaning->unit = SR_UNIT_VOLT;
248 if (info->is_power) {
249 analog->meaning->mq = SR_MQ_POWER;
250 if (info->is_decibel_mw)
251 analog->meaning->unit = SR_UNIT_DECIBEL_MW;
252 else if (info->is_watt)
253 analog->meaning->unit = SR_UNIT_WATT;
255 analog->meaning->unit = SR_UNIT_UNITLESS;
258 analog->meaning->mq = SR_MQ_GAIN;
259 analog->meaning->unit = SR_UNIT_DECIBEL_VOLT;
262 analog->meaning->mq = SR_MQ_GAIN;
263 analog->meaning->unit = SR_UNIT_UNITLESS;
265 if (info->is_logic) {
266 analog->meaning->mq = SR_MQ_GAIN;
267 analog->meaning->unit = SR_UNIT_UNITLESS;
270 /* Measurement related flags */
272 analog->meaning->mqflags |= SR_MQFLAG_AC;
274 analog->meaning->mqflags |= SR_MQFLAG_DC;
276 analog->meaning->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
278 analog->meaning->mqflags |= SR_MQFLAG_MIN;
280 analog->meaning->mqflags |= SR_MQFLAG_MAX;
282 analog->meaning->mqflags |= SR_MQFLAG_AVG;
285 static gboolean flags_valid(const struct metex14_info *info)
289 /* Does the packet have more than one multiplier? */
291 count += (info->is_pico) ? 1 : 0;
292 count += (info->is_nano) ? 1 : 0;
293 count += (info->is_micro) ? 1 : 0;
294 count += (info->is_milli) ? 1 : 0;
295 count += (info->is_kilo) ? 1 : 0;
296 count += (info->is_mega) ? 1 : 0;
298 sr_dbg("More than one multiplier detected in packet.");
302 /* Does the packet "measure" more than one type of value? */
304 count += (info->is_ac) ? 1 : 0;
305 count += (info->is_dc) ? 1 : 0;
306 count += (info->is_resistance) ? 1 : 0;
307 count += (info->is_capacity) ? 1 : 0;
308 count += (info->is_temperature) ? 1 : 0;
309 count += (info->is_diode) ? 1 : 0;
310 count += (info->is_frequency) ? 1 : 0;
312 sr_dbg("More than one measurement type detected in packet.");
316 /* Both AC and DC set? */
317 if (info->is_ac && info->is_dc) {
318 sr_dbg("Both AC and DC flags detected in packet.");
325 #ifdef HAVE_LIBSERIALPORT
326 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
328 const uint8_t wbuf = 'D';
330 sr_spew("Requesting DMM packet.");
332 return serial_write_blocking(serial, &wbuf, 1, 0);
336 SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
338 struct metex14_info info;
340 memset(&info, 0x00, sizeof(struct metex14_info));
341 parse_flags((const char *)buf, &info);
343 if (!flags_valid(&info))
352 SR_PRIV gboolean sr_metex14_4packets_valid(const uint8_t *buf)
354 struct metex14_info info;
356 const uint8_t *ch_buf;
359 for (ch_idx = 0; ch_idx < 4; ch_idx++) {
360 if (ch_buf[13] != '\r')
362 memset(&info, 0x00, sizeof(info));
363 parse_flags((const char *)ch_buf, &info);
364 if (!flags_valid(&info))
366 ch_buf += METEX14_PACKET_SIZE;
372 * Parse a protocol packet.
374 * @param buf Buffer containing the protocol packet. Must not be NULL.
375 * @param floatval Pointer to a float variable. That variable will be modified
376 * in-place depending on the protocol packet. Must not be NULL.
377 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
378 * filled with data according to the protocol packet.
380 * @param info Pointer to a struct metex14_info. The struct will be filled
381 * with data according to the protocol packet. Must not be NULL.
383 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
384 * 'analog' variable contents are undefined and should not be used.
386 SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
387 struct sr_datafeed_analog *analog, void *info)
389 int ret, exponent = 0;
390 struct metex14_info *info_local;
392 info_local = (struct metex14_info *)info;
394 /* Don't print byte 13. That one contains the carriage return. */
395 sr_dbg("DMM packet: \"%.13s\"", buf);
397 memset(info_local, 0x00, sizeof(struct metex14_info));
399 if ((ret = parse_value(buf, info_local, floatval, &exponent)) != SR_OK) {
400 sr_dbg("Error parsing value: %d.", ret);
404 parse_flags((const char *)buf, info_local);
405 handle_flags(analog, floatval, &exponent, info_local);
407 analog->encoding->digits = -exponent;
408 analog->spec->spec_digits = -exponent;
414 * Parse one out of four values of a four-display Metex14 variant.
416 * The caller's 'info' parameter can be used to track the channel index,
417 * as long as the information is kept across calls to the 14-byte packet
418 * parse routine (which clears the 'info' container).
420 * Since analog values have further details in the 'analog' parameter,
421 * passing multiple values per parse routine call is problematic. So we
422 * prefer the approach of passing one value per call, which is most
423 * reliable and shall fit every similar device with multiple displays.
425 * The meters which use this parse routine send one 14-byte packet per
426 * display. Each packet has the regular Metex14 layout.
428 SR_PRIV int sr_metex14_4packets_parse(const uint8_t *buf, float *floatval,
429 struct sr_datafeed_analog *analog, void *info)
431 struct metex14_info *info_local;
433 const uint8_t *ch_buf;
437 ch_idx = info_local->ch_idx;
438 ch_buf = buf + ch_idx * METEX14_PACKET_SIZE;
439 rc = sr_metex14_parse(ch_buf, floatval, analog, info);
440 info_local->ch_idx = ch_idx + 1;