[libsigrok.git] / src / dmm / metex14.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

/**
 * @file
 *
 * Metex 14-bytes ASCII protocol parser.
 *
 * @internal
 * This should work for various multimeters which use this kind of protocol,
 * even though there is some variation in which modes each DMM supports.
 *
 * It does _not_ work for all Metex DMMs, some use a quite different protocol.
 */

#include <config.h>
#include <string.h>
#include <strings.h>
#include <ctype.h>
#include <math.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

#define LOG_PREFIX "metex14"

/** Parse value from buf, byte 2-8. */
static int parse_value(const uint8_t *buf, struct metex14_info *info,
			float *result, int *exponent)
{
	int i, is_ol, cnt, dot_pos;
	char valstr[7 + 1];

	/* Strip all spaces from bytes 2-8. */
	memset(&valstr, 0, 7 + 1);
	for (i = 0, cnt = 0; i < 7; i++) {
		if (buf[2 + i] != ' ')
			valstr[cnt++] = buf[2 + i];
	}

	/* Bytes 5-7: Over limit (various forms) */
	is_ol = 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, ".OL")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "O.L")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "OL.")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "OL")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-.OL")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-O.L")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL.")) ? 1 : 0;
	is_ol += (!g_ascii_strcasecmp((const char *)&valstr, "-OL")) ? 1 : 0;
	if (is_ol != 0) {
		sr_spew("Over limit.");
		*result = INFINITY;
		return SR_OK;
	}

	/* Logic functions */
	if (!strcmp((const char *)&valstr, "READY") ||
			!strcmp((const char *)&valstr, "FLOAT")) {
		*result = INFINITY;
		info->is_logic = TRUE;
	} else if (!strcmp((const char *)&valstr, "Hi")) {
		*result = 1.0;
		info->is_logic = TRUE;
	} else if (!strcmp((const char *)&valstr, "Lo")) {
		*result = 0.0;
		info->is_logic = TRUE;
	}
	if (info->is_logic)
		return SR_OK;

	/* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
	sscanf((const char *)&valstr, "%f", result);

	dot_pos = strcspn(valstr, ".");
	if (dot_pos < cnt)
		*exponent = -(cnt - dot_pos - 1);
	else
		*exponent = 0;

	sr_spew("The display value is %f.", *result);

	return SR_OK;
}

static void parse_flags(const char *buf, struct metex14_info *info)
{
	int i, cnt;
	char unit[4 + 1];
	const char *u;

	/* Bytes 0-1: Measurement mode AC, DC */
	info->is_ac = !strncmp(buf, "AC", 2);
	info->is_dc = !strncmp(buf, "DC", 2);

	/* Bytes 2-8: See parse_value(). */

	/* Strip all spaces from bytes 9-12. */
	memset(&unit, 0, 4 + 1);
	for (i = 0, cnt = 0; i < 4; i++) {
		if (buf[9 + i] != ' ')
			unit[cnt++] = buf[9 + i];
	}

	/* Bytes 9-12: Unit */
	u = (const char *)&unit;
	if (!g_ascii_strcasecmp(u, "A"))
		info->is_ampere = TRUE;
	else if (!g_ascii_strcasecmp(u, "mA"))
		info->is_milli = info->is_ampere = TRUE;
	else if (!g_ascii_strcasecmp(u, "uA"))
		info->is_micro = info->is_ampere = TRUE;
	else if (!g_ascii_strcasecmp(u, "V"))
		info->is_volt = TRUE;
	else if (!g_ascii_strcasecmp(u, "mV"))
		info->is_milli = info->is_volt = TRUE;
	else if (!g_ascii_strcasecmp(u, "Ohm"))
		info->is_ohm = TRUE;
	else if (!g_ascii_strcasecmp(u, "KOhm"))
		info->is_kilo = info->is_ohm = TRUE;
	else if (!g_ascii_strcasecmp(u, "MOhm"))
		info->is_mega = info->is_ohm = TRUE;
	else if (!g_ascii_strcasecmp(u, "pF"))
		info->is_pico = info->is_farad = TRUE;
	else if (!g_ascii_strcasecmp(u, "nF"))
		info->is_nano = info->is_farad = TRUE;
	else if (!g_ascii_strcasecmp(u, "uF"))
		info->is_micro = info->is_farad = TRUE;
	else if (!g_ascii_strcasecmp(u, "KHz"))
		info->is_kilo = info->is_hertz = TRUE;
	else if (!g_ascii_strcasecmp(u, "C"))
		info->is_celsius = TRUE;
	else if (!g_ascii_strcasecmp(u, "DB"))
		info->is_decibel = TRUE;
	else if (!g_ascii_strcasecmp(u, ""))
		info->is_unitless = TRUE;

	/* Bytes 0-1: Measurement mode, except AC/DC */
	info->is_resistance  = !strncmp(buf, "OH", 2) ||
		(!strncmp(buf, "  ", 2) && info->is_ohm);
	info->is_capacity    = !strncmp(buf, "CA", 2) ||
		(!strncmp(buf, "  ", 2) && info->is_farad);
	info->is_temperature = !strncmp(buf, "TE", 2);
	info->is_diode       = !strncmp(buf, "DI", 2) ||
		(!strncmp(buf, "  ", 2) && info->is_volt && info->is_milli);
	info->is_frequency   = !strncmp(buf, "FR", 2) ||
		(!strncmp(buf, "  ", 2) && info->is_hertz);
	info->is_gain        = !strncmp(buf, "DB", 2);
	info->is_hfe         = !strncmp(buf, "HF", 2) ||
		(!strncmp(buf, "  ", 2) && !info->is_volt && !info->is_ohm &&
		 !info->is_logic && !info->is_farad && !info->is_hertz);
	/*
	 * Note:
	 * - Protocol doesn't distinguish "resistance" from "beep" mode.
	 * - "DB" shows the logarithmic ratio of input voltage to a
	 *   pre-stored (user-changeable) value in the DMM.
	 */

	/* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
}

static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
			 int *exponent, const struct metex14_info *info)
{
	int factor = 0;
	/* Factors */
	if (info->is_pico)
		factor -= 12;
	if (info->is_nano)
		factor -= 9;
	if (info->is_micro)
		factor -= 6;
	if (info->is_milli)
		factor -= 3;
	if (info->is_kilo)
		factor += 3;
	if (info->is_mega)
		factor += 6;
	*floatval *= powf(10, factor);
	*exponent += factor;

	/* Measurement modes */
	if (info->is_volt) {
		analog->meaning->mq = SR_MQ_VOLTAGE;
		analog->meaning->unit = SR_UNIT_VOLT;
	}
	if (info->is_ampere) {
		analog->meaning->mq = SR_MQ_CURRENT;
		analog->meaning->unit = SR_UNIT_AMPERE;
	}
	if (info->is_ohm) {
		analog->meaning->mq = SR_MQ_RESISTANCE;
		analog->meaning->unit = SR_UNIT_OHM;
	}
	if (info->is_hertz) {
		analog->meaning->mq = SR_MQ_FREQUENCY;
		analog->meaning->unit = SR_UNIT_HERTZ;
	}
	if (info->is_farad) {
		analog->meaning->mq = SR_MQ_CAPACITANCE;
		analog->meaning->unit = SR_UNIT_FARAD;
	}
	if (info->is_celsius) {
		analog->meaning->mq = SR_MQ_TEMPERATURE;
		analog->meaning->unit = SR_UNIT_CELSIUS;
	}
	if (info->is_diode) {
		analog->meaning->mq = SR_MQ_VOLTAGE;
		analog->meaning->unit = SR_UNIT_VOLT;
	}
	if (info->is_gain) {
		analog->meaning->mq = SR_MQ_GAIN;
		analog->meaning->unit = SR_UNIT_DECIBEL_VOLT;
	}
	if (info->is_hfe) {
		analog->meaning->mq = SR_MQ_GAIN;
		analog->meaning->unit = SR_UNIT_UNITLESS;
	}
	if (info->is_logic) {
		analog->meaning->mq = SR_MQ_GAIN;
		analog->meaning->unit = SR_UNIT_UNITLESS;
	}

	/* Measurement related flags */
	if (info->is_ac)
		analog->meaning->mqflags |= SR_MQFLAG_AC;
	if (info->is_dc)
		analog->meaning->mqflags |= SR_MQFLAG_DC;
	if (info->is_diode)
		analog->meaning->mqflags |= SR_MQFLAG_DIODE;
}

static gboolean flags_valid(const struct metex14_info *info)
{
	int count;

	/* Does the packet have more than one multiplier? */
	count = 0;
	count += (info->is_pico) ? 1 : 0;
	count += (info->is_nano) ? 1 : 0;
	count += (info->is_micro) ? 1 : 0;
	count += (info->is_milli) ? 1 : 0;
	count += (info->is_kilo) ? 1 : 0;
	count += (info->is_mega) ? 1 : 0;
	if (count > 1) {
		sr_dbg("More than one multiplier detected in packet.");
		return FALSE;
	}

	/* Does the packet "measure" more than one type of value? */
	count = 0;
	count += (info->is_ac) ? 1 : 0;
	count += (info->is_dc) ? 1 : 0;
	count += (info->is_resistance) ? 1 : 0;
	count += (info->is_capacity) ? 1 : 0;
	count += (info->is_temperature) ? 1 : 0;
	count += (info->is_diode) ? 1 : 0;
	count += (info->is_frequency) ? 1 : 0;
	if (count > 1) {
		sr_dbg("More than one measurement type detected in packet.");
		return FALSE;
	}

	/* Both AC and DC set? */
	if (info->is_ac && info->is_dc) {
		sr_dbg("Both AC and DC flags detected in packet.");
		return FALSE;
	}

	return TRUE;
}

#ifdef HAVE_LIBSERIALPORT
SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
{
	const uint8_t wbuf = 'D';

	sr_spew("Requesting DMM packet.");

	return (serial_write_nonblocking(serial, &wbuf, 1) == 1) ? SR_OK : SR_ERR;
}
#endif

SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
{
	struct metex14_info info;

	memset(&info, 0x00, sizeof(struct metex14_info));
	parse_flags((const char *)buf, &info);

	if (!flags_valid(&info))
		return FALSE;

	if (buf[13] != '\r')
		return FALSE;

	return TRUE;
}

/**
 * Parse a protocol packet.
 *
 * @param buf Buffer containing the protocol packet. Must not be NULL.
 * @param floatval Pointer to a float variable. That variable will be modified
 *                 in-place depending on the protocol packet. Must not be NULL.
 * @param analog Pointer to a struct sr_datafeed_analog. The struct will be
 *               filled with data according to the protocol packet.
 *               Must not be NULL.
 * @param info Pointer to a struct metex14_info. The struct will be filled
 *             with data according to the protocol packet. Must not be NULL.
 *
 * @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
 *         'analog' variable contents are undefined and should not be used.
 */
SR_PRIV int sr_metex14_parse(const uint8_t *buf, float *floatval,
			     struct sr_datafeed_analog *analog, void *info)
{
	int ret, exponent = 0;
	struct metex14_info *info_local;

	info_local = (struct metex14_info *)info;

	/* Don't print byte 13. That one contains the carriage return. */
	sr_dbg("DMM packet: \"%.13s\"", buf);

	memset(info_local, 0x00, sizeof(struct metex14_info));

	if ((ret = parse_value(buf, info_local, floatval, &exponent)) != SR_OK) {
		sr_dbg("Error parsing value: %d.", ret);
		return ret;
	}

	parse_flags((const char *)buf, info_local);
	handle_flags(analog, floatval, &exponent, info_local);

	analog->encoding->digits  = -exponent;
	analog->spec->spec_digits = -exponent;

	return SR_OK;
}
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2012-2013 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	* @file
	23	*
	24	* Metex 14-bytes ASCII protocol parser.
	25	*
	26	* @internal
	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.
	29	*
	30	* It does _not_ work for all Metex DMMs, some use a quite different protocol.
	31	*/
	32
	33	#include <config.h>
	34	#include <string.h>
	35	#include <strings.h>
	36	#include <ctype.h>
	37	#include <math.h>
	38	#include <glib.h>
	39	#include <libsigrok/libsigrok.h>
	40	#include "libsigrok-internal.h"
	41
	42	#define LOG_PREFIX "metex14"
	43
	44	/** Parse value from buf, byte 2-8. */
	45	static int parse_value(const uint8_t buf, struct metex14_info info,
	46	float result, int exponent)
	47	{
	48	int i, is_ol, cnt, dot_pos;
	49	char valstr[7 + 1];
	50
	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];
	56	}
	57
	58	/* Bytes 5-7: Over limit (various forms) */
	59	is_ol = 0;
	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;
	68	if (is_ol != 0) {
	69	sr_spew("Over limit.");
	70	*result = INFINITY;
	71	return SR_OK;
	72	}
	73
	74	/* Logic functions */
	75	if (!strcmp((const char *)&valstr, "READY") \|\|
	76	!strcmp((const char *)&valstr, "FLOAT")) {
	77	*result = INFINITY;
	78	info->is_logic = TRUE;
	79	} else if (!strcmp((const char *)&valstr, "Hi")) {
	80	*result = 1.0;
	81	info->is_logic = TRUE;
	82	} else if (!strcmp((const char *)&valstr, "Lo")) {
	83	*result = 0.0;
	84	info->is_logic = TRUE;
	85	}
	86	if (info->is_logic)
	87	return SR_OK;
	88
	89	/* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
	90	sscanf((const char *)&valstr, "%f", result);
	91
	92	dot_pos = strcspn(valstr, ".");
	93	if (dot_pos < cnt)
	94	*exponent = -(cnt - dot_pos - 1);
	95	else
	96	*exponent = 0;
	97
	98	sr_spew("The display value is %f.", *result);
	99
	100	return SR_OK;
	101	}
	102
	103	static void parse_flags(const char buf, struct metex14_info info)
	104	{
	105	int i, cnt;
	106	char unit[4 + 1];
	107	const char *u;
	108
	109	/* Bytes 0-1: Measurement mode AC, DC */
	110	info->is_ac = !strncmp(buf, "AC", 2);
	111	info->is_dc = !strncmp(buf, "DC", 2);
	112
	113	/* Bytes 2-8: See parse_value(). */
	114
	115	/* Strip all spaces from bytes 9-12. */
	116	memset(&unit, 0, 4 + 1);
	117	for (i = 0, cnt = 0; i < 4; i++) {
	118	if (buf[9 + i] != ' ')
	119	unit[cnt++] = buf[9 + i];
	120	}
	121
	122	/* Bytes 9-12: Unit */
	123	u = (const char *)&unit;
	124	if (!g_ascii_strcasecmp(u, "A"))
	125	info->is_ampere = TRUE;
	126	else if (!g_ascii_strcasecmp(u, "mA"))
	127	info->is_milli = info->is_ampere = TRUE;
	128	else if (!g_ascii_strcasecmp(u, "uA"))
	129	info->is_micro = info->is_ampere = TRUE;
	130	else if (!g_ascii_strcasecmp(u, "V"))
	131	info->is_volt = TRUE;
	132	else if (!g_ascii_strcasecmp(u, "mV"))
	133	info->is_milli = info->is_volt = TRUE;
	134	else if (!g_ascii_strcasecmp(u, "Ohm"))
	135	info->is_ohm = TRUE;
	136	else if (!g_ascii_strcasecmp(u, "KOhm"))
	137	info->is_kilo = info->is_ohm = TRUE;
	138	else if (!g_ascii_strcasecmp(u, "MOhm"))
	139	info->is_mega = info->is_ohm = TRUE;
	140	else if (!g_ascii_strcasecmp(u, "pF"))
	141	info->is_pico = info->is_farad = TRUE;
	142	else if (!g_ascii_strcasecmp(u, "nF"))
	143	info->is_nano = info->is_farad = TRUE;
	144	else if (!g_ascii_strcasecmp(u, "uF"))
	145	info->is_micro = info->is_farad = TRUE;
	146	else if (!g_ascii_strcasecmp(u, "KHz"))
	147	info->is_kilo = info->is_hertz = TRUE;
	148	else if (!g_ascii_strcasecmp(u, "C"))
	149	info->is_celsius = TRUE;
	150	else if (!g_ascii_strcasecmp(u, "DB"))
	151	info->is_decibel = TRUE;
	152	else if (!g_ascii_strcasecmp(u, ""))
	153	info->is_unitless = TRUE;
	154
	155	/* Bytes 0-1: Measurement mode, except AC/DC */
	156	info->is_resistance = !strncmp(buf, "OH", 2) \|\|
	157	(!strncmp(buf, " ", 2) && info->is_ohm);
	158	info->is_capacity = !strncmp(buf, "CA", 2) \|\|
	159	(!strncmp(buf, " ", 2) && info->is_farad);
	160	info->is_temperature = !strncmp(buf, "TE", 2);
	161	info->is_diode = !strncmp(buf, "DI", 2) \|\|
	162	(!strncmp(buf, " ", 2) && info->is_volt && info->is_milli);
	163	info->is_frequency = !strncmp(buf, "FR", 2) \|\|
	164	(!strncmp(buf, " ", 2) && info->is_hertz);
	165	info->is_gain = !strncmp(buf, "DB", 2);
	166	info->is_hfe = !strncmp(buf, "HF", 2) \|\|
	167	(!strncmp(buf, " ", 2) && !info->is_volt && !info->is_ohm &&
	168	!info->is_logic && !info->is_farad && !info->is_hertz);
	169	/*
	170	* Note:
	171	* - Protocol doesn't distinguish "resistance" from "beep" mode.
	172	* - "DB" shows the logarithmic ratio of input voltage to a
	173	* pre-stored (user-changeable) value in the DMM.
	174	*/
	175
	176	/* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
	177	}
	178
	179	static void handle_flags(struct sr_datafeed_analog analog, float floatval,
	180	int exponent, const struct metex14_info info)
	181	{
	182	int factor = 0;
	183	/* Factors */
	184	if (info->is_pico)
	185	factor -= 12;
	186	if (info->is_nano)
	187	factor -= 9;
	188	if (info->is_micro)
	189	factor -= 6;
	190	if (info->is_milli)
	191	factor -= 3;
	192	if (info->is_kilo)
	193	factor += 3;
	194	if (info->is_mega)
	195	factor += 6;
	196	floatval = powf(10, factor);
	197	*exponent += factor;
	198
	199	/* Measurement modes */
	200	if (info->is_volt) {
	201	analog->meaning->mq = SR_MQ_VOLTAGE;
	202	analog->meaning->unit = SR_UNIT_VOLT;
	203	}
	204	if (info->is_ampere) {
	205	analog->meaning->mq = SR_MQ_CURRENT;
	206	analog->meaning->unit = SR_UNIT_AMPERE;
	207	}
	208	if (info->is_ohm) {
	209	analog->meaning->mq = SR_MQ_RESISTANCE;
	210	analog->meaning->unit = SR_UNIT_OHM;
	211	}
	212	if (info->is_hertz) {
	213	analog->meaning->mq = SR_MQ_FREQUENCY;
	214	analog->meaning->unit = SR_UNIT_HERTZ;
	215	}
	216	if (info->is_farad) {
	217	analog->meaning->mq = SR_MQ_CAPACITANCE;
	218	analog->meaning->unit = SR_UNIT_FARAD;
	219	}
	220	if (info->is_celsius) {
	221	analog->meaning->mq = SR_MQ_TEMPERATURE;
	222	analog->meaning->unit = SR_UNIT_CELSIUS;
	223	}
	224	if (info->is_diode) {
	225	analog->meaning->mq = SR_MQ_VOLTAGE;
	226	analog->meaning->unit = SR_UNIT_VOLT;
	227	}
	228	if (info->is_gain) {
	229	analog->meaning->mq = SR_MQ_GAIN;
	230	analog->meaning->unit = SR_UNIT_DECIBEL_VOLT;
	231	}
	232	if (info->is_hfe) {
	233	analog->meaning->mq = SR_MQ_GAIN;
	234	analog->meaning->unit = SR_UNIT_UNITLESS;
	235	}
	236	if (info->is_logic) {
	237	analog->meaning->mq = SR_MQ_GAIN;
	238	analog->meaning->unit = SR_UNIT_UNITLESS;
	239	}
	240
	241	/* Measurement related flags */
	242	if (info->is_ac)
	243	analog->meaning->mqflags \|= SR_MQFLAG_AC;
	244	if (info->is_dc)
	245	analog->meaning->mqflags \|= SR_MQFLAG_DC;
	246	if (info->is_diode)
	247	analog->meaning->mqflags \|= SR_MQFLAG_DIODE;
	248	}
	249
	250	static gboolean flags_valid(const struct metex14_info *info)
	251	{
	252	int count;
	253
	254	/* Does the packet have more than one multiplier? */
	255	count = 0;
	256	count += (info->is_pico) ? 1 : 0;
	257	count += (info->is_nano) ? 1 : 0;
	258	count += (info->is_micro) ? 1 : 0;
	259	count += (info->is_milli) ? 1 : 0;
	260	count += (info->is_kilo) ? 1 : 0;
	261	count += (info->is_mega) ? 1 : 0;
	262	if (count > 1) {
	263	sr_dbg("More than one multiplier detected in packet.");
	264	return FALSE;
	265	}
	266
	267	/* Does the packet "measure" more than one type of value? */
	268	count = 0;
	269	count += (info->is_ac) ? 1 : 0;
	270	count += (info->is_dc) ? 1 : 0;
	271	count += (info->is_resistance) ? 1 : 0;
	272	count += (info->is_capacity) ? 1 : 0;
	273	count += (info->is_temperature) ? 1 : 0;
	274	count += (info->is_diode) ? 1 : 0;
	275	count += (info->is_frequency) ? 1 : 0;
	276	if (count > 1) {
	277	sr_dbg("More than one measurement type detected in packet.");
	278	return FALSE;
	279	}
	280
	281	/* Both AC and DC set? */
	282	if (info->is_ac && info->is_dc) {
	283	sr_dbg("Both AC and DC flags detected in packet.");
	284	return FALSE;
	285	}
	286
	287	return TRUE;
	288	}
	289
	290	#ifdef HAVE_LIBSERIALPORT
	291	SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial)
	292	{
	293	const uint8_t wbuf = 'D';
	294
	295	sr_spew("Requesting DMM packet.");
	296
	297	return (serial_write_nonblocking(serial, &wbuf, 1) == 1) ? SR_OK : SR_ERR;
	298	}
	299	#endif
	300
	301	SR_PRIV gboolean sr_metex14_packet_valid(const uint8_t *buf)
	302	{
	303	struct metex14_info info;
	304
	305	memset(&info, 0x00, sizeof(struct metex14_info));
	306	parse_flags((const char *)buf, &info);
	307
	308	if (!flags_valid(&info))
	309	return FALSE;
	310
	311	if (buf[13] != '\r')
	312	return FALSE;
	313
	314	return TRUE;
	315	}
	316
	317	/**
	318	* Parse a protocol packet.
	319	*
	320	* @param buf Buffer containing the protocol packet. Must not be NULL.
	321	* @param floatval Pointer to a float variable. That variable will be modified
	322	* in-place depending on the protocol packet. Must not be NULL.
	323	* @param analog Pointer to a struct sr_datafeed_analog. The struct will be
	324	* filled with data according to the protocol packet.
	325	* Must not be NULL.
	326	* @param info Pointer to a struct metex14_info. The struct will be filled
	327	* with data according to the protocol packet. Must not be NULL.
	328	*
	329	* @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
	330	* 'analog' variable contents are undefined and should not be used.
	331	*/
	332	SR_PRIV int sr_metex14_parse(const uint8_t buf, float floatval,
	333	struct sr_datafeed_analog analog, void info)
	334	{
	335	int ret, exponent = 0;
	336	struct metex14_info *info_local;
	337
	338	info_local = (struct metex14_info *)info;
	339
	340	/* Don't print byte 13. That one contains the carriage return. */
	341	sr_dbg("DMM packet: \"%.13s\"", buf);
	342
	343	memset(info_local, 0x00, sizeof(struct metex14_info));
	344
	345	if ((ret = parse_value(buf, info_local, floatval, &exponent)) != SR_OK) {
	346	sr_dbg("Error parsing value: %d.", ret);
	347	return ret;
	348	}
	349
	350	parse_flags((const char *)buf, info_local);
	351	handle_flags(analog, floatval, &exponent, info_local);
	352
	353	analog->encoding->digits = -exponent;
	354	analog->spec->spec_digits = -exponent;
	355
	356	return SR_OK;
	357	}