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, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 * Metex 14-bytes ASCII protocol parser.
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.
27 * It does _not_ work for all Metex DMMs, some use a quite different protocol.
34 #include "libsigrok.h"
35 #include "libsigrok-internal.h"
37 /* Message logging helpers with subsystem-specific prefix string. */
38 #define LOG_PREFIX "metex14: "
39 #define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
40 #define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
41 #define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
42 #define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
43 #define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
44 #define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
46 static int parse_value(const uint8_t *buf, float *result)
51 /* Strip all spaces from bytes 2-8. */
52 memset(&valstr, 0, 7 + 1);
53 for (i = 0, cnt = 0; i < 7; i++) {
54 if (buf[2 + i] != ' ')
55 valstr[cnt++] = buf[2 + i];
58 /* Bytes 5-7: Over limit (various forms) */
60 is_ol += (!strcasecmp((const char *)&valstr, ".OL")) ? 1 : 0;
61 is_ol += (!strcasecmp((const char *)&valstr, "O.L")) ? 1 : 0;
62 is_ol += (!strcasecmp((const char *)&valstr, "OL.")) ? 1 : 0;
63 is_ol += (!strcasecmp((const char *)&valstr, "OL")) ? 1 : 0;
64 is_ol += (!strcasecmp((const char *)&valstr, "-.OL")) ? 1 : 0;
65 is_ol += (!strcasecmp((const char *)&valstr, "-O.L")) ? 1 : 0;
66 is_ol += (!strcasecmp((const char *)&valstr, "-OL.")) ? 1 : 0;
67 is_ol += (!strcasecmp((const char *)&valstr, "-OL")) ? 1 : 0;
69 sr_spew("Over limit.");
74 /* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
75 sscanf((const char *)&valstr, "%f", result);
77 sr_spew("The display value is %f.", *result);
82 static void parse_flags(const char *buf, struct metex14_info *info)
88 /* Bytes 0-1: Measurement mode */
89 /* Note: Protocol doesn't distinguish "resistance" from "beep" mode. */
90 info->is_ac = !strncmp(buf, "AC", 2);
91 info->is_dc = !strncmp(buf, "DC", 2);
92 info->is_resistance = !strncmp(buf, "OH", 2);
93 info->is_capacity = !strncmp(buf, "CA", 2);
94 info->is_temperature = !strncmp(buf, "TE", 2);
95 info->is_diode = !strncmp(buf, "DI", 2);
96 info->is_frequency = !strncmp(buf, "FR", 2);
97 info->is_gain = !strncmp(buf, "DB", 2);
98 info->is_hfe = !strncmp(buf, "HF", 2);
101 * Note: "DB" shows the logarithmic ratio of input voltage to a
102 * pre-stored (user-changeable) value in the DMM.
105 if (info->is_dc || info->is_ac)
106 info->is_volt = TRUE;
108 /* Bytes 2-8: See parse_value(). */
110 /* Strip all spaces from bytes 9-12. */
111 memset(&unit, 0, 4 + 1);
112 for (i = 0, cnt = 0; i < 4; i++) {
113 if (buf[9 + i] != ' ')
114 unit[cnt++] = buf[9 + i];
117 /* Bytes 9-12: Unit */
118 u = (const char *)&unit;
119 if (!strcasecmp(u, "A"))
120 info->is_ampere = TRUE;
121 else if (!strcasecmp(u, "mA"))
122 info->is_milli = info->is_ampere = TRUE;
123 else if (!strcasecmp(u, "uA"))
124 info->is_micro = info->is_ampere = TRUE;
125 else if (!strcasecmp(u, "V"))
126 info->is_volt = TRUE;
127 else if (!strcasecmp(u, "mV"))
128 info->is_milli = info->is_volt = TRUE;
129 else if (!strcasecmp(u, "Ohm"))
131 else if (!strcasecmp(u, "KOhm"))
132 info->is_kilo = info->is_ohm = TRUE;
133 else if (!strcasecmp(u, "MOhm"))
134 info->is_mega = info->is_ohm = TRUE;
135 else if (!strcasecmp(u, "pF"))
136 info->is_pico = info->is_farad = TRUE;
137 else if (!strcasecmp(u, "nF"))
138 info->is_nano = info->is_farad = TRUE;
139 else if (!strcasecmp(u, "uF"))
140 info->is_micro = info->is_farad = TRUE;
141 else if (!strcasecmp(u, "KHz"))
142 info->is_kilo = info->is_hertz = TRUE;
143 else if (!strcasecmp(u, "C"))
144 info->is_celsius = TRUE;
145 else if (!strcasecmp(u, "DB"))
146 info->is_decibel = TRUE;
147 else if (!strcasecmp(u, ""))
148 info->is_unitless = TRUE;
150 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
153 static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
154 const struct metex14_info *info)
158 *floatval /= 1000000000000ULL;
160 *floatval /= 1000000000;
162 *floatval /= 1000000;
168 *floatval *= 1000000;
170 /* Measurement modes */
172 analog->mq = SR_MQ_VOLTAGE;
173 analog->unit = SR_UNIT_VOLT;
175 if (info->is_ampere) {
176 analog->mq = SR_MQ_CURRENT;
177 analog->unit = SR_UNIT_AMPERE;
180 analog->mq = SR_MQ_RESISTANCE;
181 analog->unit = SR_UNIT_OHM;
183 if (info->is_hertz) {
184 analog->mq = SR_MQ_FREQUENCY;
185 analog->unit = SR_UNIT_HERTZ;
187 if (info->is_farad) {
188 analog->mq = SR_MQ_CAPACITANCE;
189 analog->unit = SR_UNIT_FARAD;
191 if (info->is_celsius) {
192 analog->mq = SR_MQ_TEMPERATURE;
193 analog->unit = SR_UNIT_CELSIUS;
195 if (info->is_diode) {
196 analog->mq = SR_MQ_VOLTAGE;
197 analog->unit = SR_UNIT_VOLT;
200 analog->mq = SR_MQ_GAIN;
201 analog->unit = SR_UNIT_DECIBEL_VOLT;
204 analog->mq = SR_MQ_GAIN;
205 analog->unit = SR_UNIT_UNITLESS;
208 /* Measurement related flags */
210 analog->mqflags |= SR_MQFLAG_AC;
212 analog->mqflags |= SR_MQFLAG_DC;
214 analog->mqflags |= SR_MQFLAG_DIODE;
217 static gboolean flags_valid(const struct metex14_info *info)
221 /* Does the packet have more than one multiplier? */
223 count += (info->is_pico) ? 1 : 0;
224 count += (info->is_nano) ? 1 : 0;
225 count += (info->is_micro) ? 1 : 0;
226 count += (info->is_milli) ? 1 : 0;
227 count += (info->is_kilo) ? 1 : 0;
228 count += (info->is_mega) ? 1 : 0;
230 sr_err("More than one multiplier detected in packet.");
234 /* Does the packet "measure" more than one type of value? */
236 count += (info->is_ac) ? 1 : 0;
237 count += (info->is_dc) ? 1 : 0;
238 count += (info->is_resistance) ? 1 : 0;
239 count += (info->is_capacity) ? 1 : 0;
240 count += (info->is_temperature) ? 1 : 0;
241 count += (info->is_diode) ? 1 : 0;
242 count += (info->is_frequency) ? 1 : 0;
244 sr_err("More than one measurement type detected in packet.");
248 /* Both AC and DC set? */
249 if (info->is_ac && info->is_dc) {
250 sr_err("Both AC and DC flags detected in packet.");
257 #ifdef HAVE_LIBSERIALPORT
258 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
260 const uint8_t wbuf = 'D';
262 sr_spew("Requesting DMM packet.");
264 return (serial_write(serial, &wbuf, 1) == 1) ? SR_OK : SR_ERR;
268 SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
270 struct metex14_info info;
272 memset(&info, 0x00, sizeof(struct metex14_info));
273 parse_flags((const char *)buf, &info);
275 if (!flags_valid(&info))
285 * Parse a protocol packet.
287 * @param buf Buffer containing the protocol packet. Must not be NULL.
288 * @param floatval Pointer to a float variable. That variable will be modified
289 * in-place depending on the protocol packet. Must not be NULL.
290 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
291 * filled with data according to the protocol packet.
293 * @param info Pointer to a struct metex14_info. The struct will be filled
294 * with data according to the protocol packet. Must not be NULL.
296 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
297 * 'analog' variable contents are undefined and should not be used.
299 SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
300 struct sr_datafeed_analog *analog, void *info)
303 struct metex14_info *info_local;
305 info_local = (struct metex14_info *)info;
307 /* Don't print byte 13. That one contains the carriage return. */
308 sr_dbg("DMM packet: \"%.13s\"", buf);
310 if ((ret = parse_value(buf, floatval)) != SR_OK) {
311 sr_err("Error parsing value: %d.", ret);
315 memset(info_local, 0x00, sizeof(struct metex14_info));
316 parse_flags((const char *)buf, info_local);
317 handle_flags(analog, floatval, info_local);