]> sigrok.org Git - libsigrok.git/blame - hardware/common/dmm/metex14.c
fs9721: Pass 'info' as a void pointer.
[libsigrok.git] / hardware / common / dmm / metex14.c
CommitLineData
ac913e5c
UH
1/*
2 * This file is part of the sigrok project.
3 *
4 * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
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 2 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, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/*
22 * Metex 14-bytes ASCII protocol parser.
23 *
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.
26 *
27 * It does _not_ work for all Metex DMMs, some use a quite different protocol.
28 */
29
30#include <string.h>
31#include <ctype.h>
32#include <math.h>
33#include <glib.h>
34#include "libsigrok.h"
35#include "libsigrok-internal.h"
36
37/* Message logging helpers with driver-specific prefix string. */
38#define DRIVER_LOG_DOMAIN "metex14: "
39#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
40#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
41#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
42#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
43#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
44#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
45
46static int parse_value(const uint8_t *buf, float *result)
47{
48 int i, sign, intval = 0, factor, decimal_point = 0, is_ol;
49 float floatval;
50 uint8_t digit;
51
52 /* Byte 3: Sign (' ' or '-') */
53 if (buf[3] == ' ') {
54 sign = 1;
55 } else if (buf[3] == '-') {
56 sign = -1;
57 } else {
58 sr_err("Invalid sign byte: 0x%02x.", buf[3]);
59 return SR_ERR;
60 }
61
62 /* Bytes 5-7: Over limit (various forms) */
63 is_ol = 0;
64 is_ol += !strncmp((char *)&buf[5], ".OL", 3);
65 is_ol += !strncmp((char *)&buf[5], "O.L", 3);
66 is_ol += !strncmp((char *)&buf[5], "OL.", 3);
67 is_ol += !strncmp((char *)&buf[5], " OL", 3);
68 if (is_ol != 0) {
69 sr_spew("Over limit.");
70 *result = INFINITY;
71 return SR_OK;
72 }
73
74 /* Bytes 4-8: Value (up to 4 digits) and decimal point */
75 factor = 1000;
76 for (i = 0; i < 5; i++) {
77 digit = buf[4 + i];
78 if (digit == '.') {
79 decimal_point = i;
80 } else if (isdigit(digit)) {
81 intval += (digit - '0') * factor;
82 factor /= 10;
83 } else {
84 sr_err("Invalid digit byte: 0x%02x.", digit);
85 return SR_ERR;
86 }
87 }
88
89 floatval = (float)intval;
90
91 /* Decimal point position */
92 if (decimal_point == 0 || decimal_point == 4) {
93 /* TODO: Doesn't happen? */
94 } else if (decimal_point == 1) {
95 floatval /= 1000;
96 } else if (decimal_point == 2) {
97 floatval /= 100;
98 } else if (decimal_point == 3) {
99 floatval /= 10;
100 } else {
101 sr_err("Invalid decimal point position: %d.", decimal_point);
102 return SR_ERR;
103 }
104
105 /* Apply sign. */
106 floatval *= sign;
107
108 sr_spew("The display value is %f.", floatval);
109
110 *result = floatval;
111
112 return SR_OK;
113}
114
115static void parse_flags(const char *buf, struct metex14_info *info)
116{
117 /* Bytes 0-1: Measurement mode */
118 /* Note: Protocol doesn't distinguish "resistance" from "beep" mode. */
119 info->is_ac = !strncmp(buf, "AC", 2);
120 info->is_dc = !strncmp(buf, "DC", 2);
121 info->is_resistance = !strncmp(buf, "OH", 2);
122 info->is_capacity = !strncmp(buf, "CA", 2);
123 info->is_temperature = !strncmp(buf, "TE", 2);
124 info->is_diode = !strncmp(buf, "DI", 2);
125 info->is_frequency = !strncmp(buf, "FR", 2);
126
127 if (info->is_dc || info->is_ac)
128 info->is_volt = TRUE;
129
130 /* Byte 2: Always space (0x20). */
131
132 /* Bytes 3-8: See parse_value(). */
133
134 /* Bytes 9-12: Unit */
135 if (!strcmp(buf + 9, " A"))
136 info->is_ampere = TRUE;
137 else if (!strcmp(buf + 9, " mA"))
138 info->is_milli = info->is_ampere = TRUE;
139 else if (!strcmp(buf + 9, " V"))
140 info->is_volt = TRUE;
141 else if (!strcmp(buf + 9, " mV"))
142 info->is_milli = info->is_volt = TRUE;
143 else if (!strcmp(buf + 9, " Ohm"))
144 info->is_ohm = TRUE;
145 else if (!strcmp(buf + 9, "KOhm"))
146 info->is_kilo = info->is_ohm = TRUE;
147 else if (!strcmp(buf + 9, "MOhm"))
148 info->is_mega = info->is_ohm = TRUE;
149 else if (!strcmp(buf + 9, " nF"))
150 info->is_nano = info->is_farad = TRUE;
151 else if (!strcmp(buf + 9, " uF"))
152 info->is_micro = info->is_farad = TRUE;
153 else if (!strcmp(buf + 9, " KHz"))
154 info->is_kilo = info->is_hertz = TRUE;
155 else if (!strcmp(buf + 9, " C"))
156 info->is_celsius = TRUE;
157
158 /* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
159}
160
161static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
162 const struct metex14_info *info)
163{
164 /* Factors */
165 if (info->is_nano)
166 *floatval /= 1000000000;
167 if (info->is_micro)
168 *floatval /= 1000000;
169 if (info->is_milli)
170 *floatval /= 1000;
171 if (info->is_kilo)
172 *floatval *= 1000;
173 if (info->is_mega)
174 *floatval *= 1000000;
175
176 /* Measurement modes */
177 if (info->is_volt) {
178 analog->mq = SR_MQ_VOLTAGE;
179 analog->unit = SR_UNIT_VOLT;
180 }
181 if (info->is_ampere) {
182 analog->mq = SR_MQ_CURRENT;
183 analog->unit = SR_UNIT_AMPERE;
184 }
185 if (info->is_ohm) {
186 analog->mq = SR_MQ_RESISTANCE;
187 analog->unit = SR_UNIT_OHM;
188 }
189 if (info->is_hertz) {
190 analog->mq = SR_MQ_FREQUENCY;
191 analog->unit = SR_UNIT_HERTZ;
192 }
193 if (info->is_farad) {
194 analog->mq = SR_MQ_CAPACITANCE;
195 analog->unit = SR_UNIT_FARAD;
196 }
197 if (info->is_celsius) {
198 analog->mq = SR_MQ_TEMPERATURE;
199 analog->unit = SR_UNIT_CELSIUS;
200 }
201 if (info->is_diode) {
202 analog->mq = SR_MQ_VOLTAGE;
203 analog->unit = SR_UNIT_VOLT;
204 }
205
206 /* Measurement related flags */
207 if (info->is_ac)
208 analog->mqflags |= SR_MQFLAG_AC;
209 if (info->is_dc)
210 analog->mqflags |= SR_MQFLAG_DC;
211}
212
213static gboolean flags_valid(const struct metex14_info *info)
214{
215 int count;
216
217 /* Does the packet have more than one multiplier? */
218 count = 0;
219 count += (info->is_nano) ? 1 : 0;
220 count += (info->is_micro) ? 1 : 0;
221 count += (info->is_milli) ? 1 : 0;
222 count += (info->is_kilo) ? 1 : 0;
223 count += (info->is_mega) ? 1 : 0;
224 if (count > 1) {
225 sr_err("More than one multiplier detected in packet.");
226 return FALSE;
227 }
228
229 /* Does the packet "measure" more than one type of value? */
230 count = 0;
231 count += (info->is_ac) ? 1 : 0;
232 count += (info->is_dc) ? 1 : 0;
233 count += (info->is_resistance) ? 1 : 0;
234 count += (info->is_capacity) ? 1 : 0;
235 count += (info->is_temperature) ? 1 : 0;
236 count += (info->is_diode) ? 1 : 0;
237 count += (info->is_frequency) ? 1 : 0;
238 if (count > 1) {
239 sr_err("More than one measurement type detected in packet.");
240 return FALSE;
241 }
242
243 /* Both AC and DC set? */
244 if (info->is_ac && info->is_dc) {
245 sr_err("Both AC and DC flags detected in packet.");
246 return FALSE;
247 }
248
249 return TRUE;
250}
251
252SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
253{
254 struct metex14_info info;
255
256 memset(&info, 0x00, sizeof(struct metex14_info));
257 parse_flags((const char *)buf, &info);
258
259 if (!flags_valid(&info))
260 return FALSE;
261
262 if (buf[13] != '\r')
263 return FALSE;
264
265 return TRUE;
266}
267
268/**
269 * Parse a protocol packet.
270 *
271 * @param buf Buffer containing the protocol packet.
272 * @param floatval Pointer to a float variable. That variable will be modified
273 * in-place depending on the protocol packet.
274 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
275 * filled with data according to the protocol packet.
276 *
277 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
278 * 'analog' variable contents are undefined and should not be used.
279 */
280SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
281 struct sr_datafeed_analog *analog,
282 struct metex14_info *info)
283{
284 int ret;
285
286 if ((ret = parse_value(buf, floatval)) != SR_OK) {
287 sr_err("Error parsing value: %d.", ret);
288 return ret;
289 }
290
291 memset(info, 0x00, sizeof(struct metex14_info));
292 parse_flags((const char *)buf, info);
293 handle_flags(analog, floatval, info);
294
295 return SR_OK;
296}