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
24 * Metex 14-bytes ASCII protocol parser.
27 * This should work for various multimeters which use this kind of protocol,
28 * even though there is some variation in which modes each DMM supports.
30 * 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,
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 += (!strcasecmp((const char *)&valstr, ".OL")) ? 1 : 0;
60 is_ol += (!strcasecmp((const char *)&valstr, "O.L")) ? 1 : 0;
61 is_ol += (!strcasecmp((const char *)&valstr, "OL.")) ? 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, "-O.L")) ? 1 : 0;
65 is_ol += (!strcasecmp((const char *)&valstr, "-OL.")) ? 1 : 0;
66 is_ol += (!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 sscanf((const char *)&valstr, "%f", result);
91 sr_spew("The display value is %f.", *result);
96 static void parse_flags(const char *buf, struct metex14_info *info)
102 /* Bytes 0-1: Measurement mode AC, DC */
103 info->is_ac = !strncmp(buf, "AC", 2);
104 info->is_dc = !strncmp(buf, "DC", 2);
106 /* Bytes 2-8: See parse_value(). */
108 /* Strip all spaces from bytes 9-12. */
109 memset(&unit, 0, 4 + 1);
110 for (i = 0, cnt = 0; i < 4; i++) {
111 if (buf[9 + i] != ' ')
112 unit[cnt++] = buf[9 + i];
115 /* Bytes 9-12: Unit */
116 u = (const char *)&unit;
117 if (!strcasecmp(u, "A"))
118 info->is_ampere = TRUE;
119 else if (!strcasecmp(u, "mA"))
120 info->is_milli = info->is_ampere = TRUE;
121 else if (!strcasecmp(u, "uA"))
122 info->is_micro = info->is_ampere = TRUE;
123 else if (!strcasecmp(u, "V"))
124 info->is_volt = TRUE;
125 else if (!strcasecmp(u, "mV"))
126 info->is_milli = info->is_volt = TRUE;
127 else if (!strcasecmp(u, "Ohm"))
129 else if (!strcasecmp(u, "KOhm"))
130 info->is_kilo = info->is_ohm = TRUE;
131 else if (!strcasecmp(u, "MOhm"))
132 info->is_mega = info->is_ohm = TRUE;
133 else if (!strcasecmp(u, "pF"))
134 info->is_pico = info->is_farad = TRUE;
135 else if (!strcasecmp(u, "nF"))
136 info->is_nano = info->is_farad = TRUE;
137 else if (!strcasecmp(u, "uF"))
138 info->is_micro = info->is_farad = TRUE;
139 else if (!strcasecmp(u, "KHz"))
140 info->is_kilo = info->is_hertz = TRUE;
141 else if (!strcasecmp(u, "C"))
142 info->is_celsius = TRUE;
143 else if (!strcasecmp(u, "DB"))
144 info->is_decibel = TRUE;
145 else if (!strcasecmp(u, ""))
146 info->is_unitless = TRUE;
148 /* Bytes 0-1: Measurement mode, except AC/DC */
149 info->is_resistance = !strncmp(buf, "OH", 2) ||
150 (!strncmp(buf, " ", 2) && info->is_ohm);
151 info->is_capacity = !strncmp(buf, "CA", 2) ||
152 (!strncmp(buf, " ", 2) && info->is_farad);
153 info->is_temperature = !strncmp(buf, "TE", 2);
154 info->is_diode = !strncmp(buf, "DI", 2) ||
155 (!strncmp(buf, " ", 2) && info->is_volt && info->is_milli);
156 info->is_frequency = !strncmp(buf, "FR", 2) ||
157 (!strncmp(buf, " ", 2) && info->is_hertz);
158 info->is_gain = !strncmp(buf, "DB", 2);
159 info->is_hfe = !strncmp(buf, "HF", 2) ||
160 (!strncmp(buf, " ", 2) && !info->is_volt && !info->is_ohm &&
161 !info->is_logic && !info->is_farad && !info->is_hertz);
164 * - Protocol doesn't distinguish "resistance" from "beep" mode.
165 * - "DB" shows the logarithmic ratio of input voltage to a
166 * pre-stored (user-changeable) value in the DMM.
169 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
172 static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
173 const struct metex14_info *info)
177 *floatval /= 1000000000000ULL;
179 *floatval /= 1000000000;
181 *floatval /= 1000000;
187 *floatval *= 1000000;
189 /* Measurement modes */
191 analog->mq = SR_MQ_VOLTAGE;
192 analog->unit = SR_UNIT_VOLT;
194 if (info->is_ampere) {
195 analog->mq = SR_MQ_CURRENT;
196 analog->unit = SR_UNIT_AMPERE;
199 analog->mq = SR_MQ_RESISTANCE;
200 analog->unit = SR_UNIT_OHM;
202 if (info->is_hertz) {
203 analog->mq = SR_MQ_FREQUENCY;
204 analog->unit = SR_UNIT_HERTZ;
206 if (info->is_farad) {
207 analog->mq = SR_MQ_CAPACITANCE;
208 analog->unit = SR_UNIT_FARAD;
210 if (info->is_celsius) {
211 analog->mq = SR_MQ_TEMPERATURE;
212 analog->unit = SR_UNIT_CELSIUS;
214 if (info->is_diode) {
215 analog->mq = SR_MQ_VOLTAGE;
216 analog->unit = SR_UNIT_VOLT;
219 analog->mq = SR_MQ_GAIN;
220 analog->unit = SR_UNIT_DECIBEL_VOLT;
223 analog->mq = SR_MQ_GAIN;
224 analog->unit = SR_UNIT_UNITLESS;
226 if (info->is_logic) {
227 analog->mq = SR_MQ_GAIN;
228 analog->unit = SR_UNIT_UNITLESS;
231 /* Measurement related flags */
233 analog->mqflags |= SR_MQFLAG_AC;
235 analog->mqflags |= SR_MQFLAG_DC;
237 analog->mqflags |= SR_MQFLAG_DIODE;
240 static gboolean flags_valid(const struct metex14_info *info)
244 /* Does the packet have more than one multiplier? */
246 count += (info->is_pico) ? 1 : 0;
247 count += (info->is_nano) ? 1 : 0;
248 count += (info->is_micro) ? 1 : 0;
249 count += (info->is_milli) ? 1 : 0;
250 count += (info->is_kilo) ? 1 : 0;
251 count += (info->is_mega) ? 1 : 0;
253 sr_dbg("More than one multiplier detected in packet.");
257 /* Does the packet "measure" more than one type of value? */
259 count += (info->is_ac) ? 1 : 0;
260 count += (info->is_dc) ? 1 : 0;
261 count += (info->is_resistance) ? 1 : 0;
262 count += (info->is_capacity) ? 1 : 0;
263 count += (info->is_temperature) ? 1 : 0;
264 count += (info->is_diode) ? 1 : 0;
265 count += (info->is_frequency) ? 1 : 0;
267 sr_dbg("More than one measurement type detected in packet.");
271 /* Both AC and DC set? */
272 if (info->is_ac && info->is_dc) {
273 sr_dbg("Both AC and DC flags detected in packet.");
280 #ifdef HAVE_LIBSERIALPORT
281 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
283 const uint8_t wbuf = 'D';
285 sr_spew("Requesting DMM packet.");
287 return (serial_write_nonblocking(serial, &wbuf, 1) == 1) ? SR_OK : SR_ERR;
291 SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
293 struct metex14_info info;
295 memset(&info, 0x00, sizeof(struct metex14_info));
296 parse_flags((const char *)buf, &info);
298 if (!flags_valid(&info))
308 * Parse a protocol packet.
310 * @param buf Buffer containing the protocol packet. Must not be NULL.
311 * @param floatval Pointer to a float variable. That variable will be modified
312 * in-place depending on the protocol packet. Must not be NULL.
313 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
314 * filled with data according to the protocol packet.
316 * @param info Pointer to a struct metex14_info. The struct will be filled
317 * with data according to the protocol packet. Must not be NULL.
319 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
320 * 'analog' variable contents are undefined and should not be used.
322 SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
323 struct sr_datafeed_analog *analog, void *info)
326 struct metex14_info *info_local;
328 info_local = (struct metex14_info *)info;
330 /* Don't print byte 13. That one contains the carriage return. */
331 sr_dbg("DMM packet: \"%.13s\"", buf);
333 memset(info_local, 0x00, sizeof(struct metex14_info));
335 if ((ret = parse_value(buf, info_local, floatval)) != SR_OK) {
336 sr_dbg("Error parsing value: %d.", ret);
340 parse_flags((const char *)buf, info_local);
341 handle_flags(analog, floatval, info_local);