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.
39 #include <libsigrok/libsigrok.h>
40 #include "libsigrok-internal.h"
42 #define LOG_PREFIX "metex14"
44 /** Parse value from buf, byte 2-8. */
45 static int parse_value(const uint8_t *buf, struct metex14_info *info,
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 += (!g_ascii_strcasecmp((const char *)&valstr, ".OL")) ? 1 : 0;
61 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "O.L")) ? 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, "-.OL")) ? 1 : 0;
65 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-O.L")) ? 1 : 0;
66 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL.")) ? 1 : 0;
67 is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL")) ? 1 : 0;
69 sr_spew("Over limit.");
75 if (!strcmp((const char *)&valstr, "READY") ||
76 !strcmp((const char *)&valstr, "FLOAT")) {
78 info->is_logic = TRUE;
79 } else if (!strcmp((const char *)&valstr, "Hi")) {
81 info->is_logic = TRUE;
82 } else if (!strcmp((const char *)&valstr, "Lo")) {
84 info->is_logic = TRUE;
89 /* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
90 sscanf((const char *)&valstr, "%f", result);
92 sr_spew("The display value is %f.", *result);
97 static void parse_flags(const char *buf, struct metex14_info *info)
103 /* Bytes 0-1: Measurement mode AC, DC */
104 info->is_ac = !strncmp(buf, "AC", 2);
105 info->is_dc = !strncmp(buf, "DC", 2);
107 /* Bytes 2-8: See parse_value(). */
109 /* Strip all spaces from bytes 9-12. */
110 memset(&unit, 0, 4 + 1);
111 for (i = 0, cnt = 0; i < 4; i++) {
112 if (buf[9 + i] != ' ')
113 unit[cnt++] = buf[9 + i];
116 /* Bytes 9-12: Unit */
117 u = (const char *)&unit;
118 if (!g_ascii_strcasecmp(u, "A"))
119 info->is_ampere = TRUE;
120 else if (!g_ascii_strcasecmp(u, "mA"))
121 info->is_milli = info->is_ampere = TRUE;
122 else if (!g_ascii_strcasecmp(u, "uA"))
123 info->is_micro = info->is_ampere = TRUE;
124 else if (!g_ascii_strcasecmp(u, "V"))
125 info->is_volt = TRUE;
126 else if (!g_ascii_strcasecmp(u, "mV"))
127 info->is_milli = info->is_volt = TRUE;
128 else if (!g_ascii_strcasecmp(u, "Ohm"))
130 else if (!g_ascii_strcasecmp(u, "KOhm"))
131 info->is_kilo = info->is_ohm = TRUE;
132 else if (!g_ascii_strcasecmp(u, "MOhm"))
133 info->is_mega = info->is_ohm = TRUE;
134 else if (!g_ascii_strcasecmp(u, "pF"))
135 info->is_pico = info->is_farad = TRUE;
136 else if (!g_ascii_strcasecmp(u, "nF"))
137 info->is_nano = info->is_farad = TRUE;
138 else if (!g_ascii_strcasecmp(u, "uF"))
139 info->is_micro = info->is_farad = TRUE;
140 else if (!g_ascii_strcasecmp(u, "KHz"))
141 info->is_kilo = info->is_hertz = TRUE;
142 else if (!g_ascii_strcasecmp(u, "C"))
143 info->is_celsius = TRUE;
144 else if (!g_ascii_strcasecmp(u, "DB"))
145 info->is_decibel = TRUE;
146 else if (!g_ascii_strcasecmp(u, ""))
147 info->is_unitless = TRUE;
149 /* Bytes 0-1: Measurement mode, except AC/DC */
150 info->is_resistance = !strncmp(buf, "OH", 2) ||
151 (!strncmp(buf, " ", 2) && info->is_ohm);
152 info->is_capacity = !strncmp(buf, "CA", 2) ||
153 (!strncmp(buf, " ", 2) && info->is_farad);
154 info->is_temperature = !strncmp(buf, "TE", 2);
155 info->is_diode = !strncmp(buf, "DI", 2) ||
156 (!strncmp(buf, " ", 2) && info->is_volt && info->is_milli);
157 info->is_frequency = !strncmp(buf, "FR", 2) ||
158 (!strncmp(buf, " ", 2) && info->is_hertz);
159 info->is_gain = !strncmp(buf, "DB", 2);
160 info->is_hfe = !strncmp(buf, "HF", 2) ||
161 (!strncmp(buf, " ", 2) && !info->is_volt && !info->is_ohm &&
162 !info->is_logic && !info->is_farad && !info->is_hertz);
165 * - Protocol doesn't distinguish "resistance" from "beep" mode.
166 * - "DB" shows the logarithmic ratio of input voltage to a
167 * pre-stored (user-changeable) value in the DMM.
170 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
173 static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
174 const struct metex14_info *info)
178 *floatval /= 1000000000000ULL;
180 *floatval /= 1000000000;
182 *floatval /= 1000000;
188 *floatval *= 1000000;
190 /* Measurement modes */
192 analog->meaning->mq = SR_MQ_VOLTAGE;
193 analog->meaning->unit = SR_UNIT_VOLT;
195 if (info->is_ampere) {
196 analog->meaning->mq = SR_MQ_CURRENT;
197 analog->meaning->unit = SR_UNIT_AMPERE;
200 analog->meaning->mq = SR_MQ_RESISTANCE;
201 analog->meaning->unit = SR_UNIT_OHM;
203 if (info->is_hertz) {
204 analog->meaning->mq = SR_MQ_FREQUENCY;
205 analog->meaning->unit = SR_UNIT_HERTZ;
207 if (info->is_farad) {
208 analog->meaning->mq = SR_MQ_CAPACITANCE;
209 analog->meaning->unit = SR_UNIT_FARAD;
211 if (info->is_celsius) {
212 analog->meaning->mq = SR_MQ_TEMPERATURE;
213 analog->meaning->unit = SR_UNIT_CELSIUS;
215 if (info->is_diode) {
216 analog->meaning->mq = SR_MQ_VOLTAGE;
217 analog->meaning->unit = SR_UNIT_VOLT;
220 analog->meaning->mq = SR_MQ_GAIN;
221 analog->meaning->unit = SR_UNIT_DECIBEL_VOLT;
224 analog->meaning->mq = SR_MQ_GAIN;
225 analog->meaning->unit = SR_UNIT_UNITLESS;
227 if (info->is_logic) {
228 analog->meaning->mq = SR_MQ_GAIN;
229 analog->meaning->unit = SR_UNIT_UNITLESS;
232 /* Measurement related flags */
234 analog->meaning->mqflags |= SR_MQFLAG_AC;
236 analog->meaning->mqflags |= SR_MQFLAG_DC;
238 analog->meaning->mqflags |= SR_MQFLAG_DIODE;
241 static gboolean flags_valid(const struct metex14_info *info)
245 /* Does the packet have more than one multiplier? */
247 count += (info->is_pico) ? 1 : 0;
248 count += (info->is_nano) ? 1 : 0;
249 count += (info->is_micro) ? 1 : 0;
250 count += (info->is_milli) ? 1 : 0;
251 count += (info->is_kilo) ? 1 : 0;
252 count += (info->is_mega) ? 1 : 0;
254 sr_dbg("More than one multiplier detected in packet.");
258 /* Does the packet "measure" more than one type of value? */
260 count += (info->is_ac) ? 1 : 0;
261 count += (info->is_dc) ? 1 : 0;
262 count += (info->is_resistance) ? 1 : 0;
263 count += (info->is_capacity) ? 1 : 0;
264 count += (info->is_temperature) ? 1 : 0;
265 count += (info->is_diode) ? 1 : 0;
266 count += (info->is_frequency) ? 1 : 0;
268 sr_dbg("More than one measurement type detected in packet.");
272 /* Both AC and DC set? */
273 if (info->is_ac && info->is_dc) {
274 sr_dbg("Both AC and DC flags detected in packet.");
281 #ifdef HAVE_LIBSERIALPORT
282 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
284 const uint8_t wbuf = 'D';
286 sr_spew("Requesting DMM packet.");
288 return (serial_write_nonblocking(serial, &wbuf, 1) == 1) ? SR_OK : SR_ERR;
292 SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
294 struct metex14_info info;
296 memset(&info, 0x00, sizeof(struct metex14_info));
297 parse_flags((const char *)buf, &info);
299 if (!flags_valid(&info))
309 * Parse a protocol packet.
311 * @param buf Buffer containing the protocol packet. Must not be NULL.
312 * @param floatval Pointer to a float variable. That variable will be modified
313 * in-place depending on the protocol packet. Must not be NULL.
314 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
315 * filled with data according to the protocol packet.
317 * @param info Pointer to a struct metex14_info. The struct will be filled
318 * with data according to the protocol packet. Must not be NULL.
320 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
321 * 'analog' variable contents are undefined and should not be used.
323 SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
324 struct sr_datafeed_analog *analog, void *info)
327 struct metex14_info *info_local;
329 info_local = (struct metex14_info *)info;
331 /* Don't print byte 13. That one contains the carriage return. */
332 sr_dbg("DMM packet: \"%.13s\"", buf);
334 memset(info_local, 0x00, sizeof(struct metex14_info));
336 if ((ret = parse_value(buf, info_local, floatval)) != SR_OK) {
337 sr_dbg("Error parsing value: %d.", ret);
341 parse_flags((const char *)buf, info_local);
342 handle_flags(analog, floatval, info_local);