--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2018 Matthias Schulz <matthschulz@arcor.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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Voltcraft 13-bytes ASCII protocol parser.
+ *
+ * Bytes 1-3 measuring mode, byte 4 '-' for negative,
+ * bytes 5-9 value, bytes 10-11 unit, bytes 12-13 CRLF 0d 0a.
+ */
+
+#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 "vc96"
+
+/** Parse value from buf, byte 3-8. */
+static int parse_value(const uint8_t *buf, struct vc96_info *info,
+ float *result, int *exponent)
+{
+ int i, is_ol, cnt, dot_pos;
+ char valstr[8 + 1];
+
+ (void)info;
+
+ /* Strip all spaces from bytes 3-8. */
+ memset(&valstr, 0, 6 + 1);
+ for (i = 0, cnt = 0; i < 6; i++) {
+ if (buf[3 + i] != ' ')
+ valstr[cnt++] = buf[3 + 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;
+ }
+
+ /* Bytes 3-10: Sign, value (up to 5 digits) and decimal point */
+ sr_atof_ascii((const char *)&valstr, 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 vc96_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 0-2: Measurement mode DIO, OHM */
+ info->is_ohm = !strncmp(buf, "OHM", 3);
+ info->is_diode = !strncmp(buf, "DIO", 3);
+ info->is_hfe = !strncmp(buf, "hfe", 3);
+
+ /* Bytes 3-8: See parse_value(). */
+
+ /* Strip all spaces from bytes 9-10. */
+ memset(&unit, 0, 2 + 1);
+ for (i = 0, cnt = 0; i < 2; i++) {
+ if (buf[9 + i] != ' ')
+ unit[cnt++] = buf[9 + i];
+ }
+ sr_spew("Bytes 9..10 without spaces \"%.4s\".", unit);
+
+ /* Bytes 9-10: Unit */
+ u = (const char *)&unit;
+ if (!g_ascii_strcasecmp(u, "A"))
+ {info->is_ampere = TRUE; sr_spew("is ampere");}
+ else if (!g_ascii_strcasecmp(u, "mA"))
+ {info->is_milli = info->is_ampere = TRUE; sr_spew("is milli ampere");}
+ else if (!g_ascii_strcasecmp(u, "uA"))
+ {info->is_micro = info->is_ampere = TRUE; sr_spew("is micro ampere");}
+ else if (!g_ascii_strcasecmp(u, "V"))
+ {info->is_volt = TRUE; sr_spew("is volt");}
+ else if (!g_ascii_strcasecmp(u, "mV"))
+ {info->is_milli = info->is_volt = TRUE; sr_spew("is milli volt");}
+ else if (!g_ascii_strcasecmp(u, "K"))
+ {info->is_kilo = TRUE; sr_spew("is kilo");}
+ else if (!g_ascii_strcasecmp(u, "M"))
+ {info->is_mega = TRUE; sr_spew("is mega");}
+ else if (!g_ascii_strcasecmp(u, ""))
+ {info->is_unitless = TRUE; sr_spew("is unitless");}
+
+ /* Bytes 0-2: Measurement mode, except AC/DC */
+ info->is_resistance = !strncmp(buf, "OHM", 3) ||
+ (!strncmp(buf, " ", 3) && info->is_ohm);
+ info->is_diode = !strncmp(buf, "DIO", 3) ||
+ (!strncmp(buf, " ", 3) && info->is_volt && info->is_milli);
+ info->is_hfe = !strncmp(buf, "hfe", 3) ||
+ (!strncmp(buf, " ", 3) && !info->is_ampere && !info->is_volt &&
+ !info->is_resistance && !info->is_diode);
+
+ /*
+ * Note:
+ * - Protocol doesn't distinguish "resistance" from "beep" mode.
+ */
+
+ /* Byte 12: Always '\r' (carriage return, 0x0d, 12) */
+ /* Byte 13: Always '\n' (carriage return, 0x0a, 13) */
+}
+
+static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
+ int *exponent, const struct vc96_info *info)
+{
+ int factor;
+
+ (void)exponent;
+
+ /* Factors */
+ factor = 0;
+ 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);
+
+ /* 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_diode) {
+ analog->meaning->mq = SR_MQ_VOLTAGE;
+ analog->meaning->unit = SR_UNIT_VOLT;
+ }
+ if (info->is_hfe) {
+ 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 | SR_MQFLAG_DC;
+}
+
+static gboolean flags_valid(const struct vc96_info *info)
+{
+ int count;
+
+ /* Does the packet have more than one multiplier? */
+ count = 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_diode) ? 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;
+}
+
+SR_PRIV gboolean sr_vc96_packet_valid(const uint8_t *buf)
+{
+ struct vc96_info info;
+
+ memset(&info, 0x00, sizeof(struct vc96_info));
+ parse_flags((const char *)buf, &info);
+
+ if (!flags_valid(&info)) {
+ sr_dbg("flags_valid = 0.");
+ return FALSE;
+ };
+
+ if ((buf[11] != '\r') || (buf[12] != '\n')) {
+ sr_dbg("CR LF not correct detected.");
+ 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 vc96_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_vc96_parse(const uint8_t *buf, float *floatval,
+ struct sr_datafeed_analog *analog, void *info)
+{
+ int ret, exponent = 0;
+ struct vc96_info *info_local;
+
+ info_local = info;
+
+ /* Don't print byte 12 + 13. Those contain the CR LF. */
+ sr_dbg("DMM packet: \"%.11s\".", buf);
+
+ memset(info_local, 0x00, sizeof(struct vc96_info));
+
+ if ((ret = parse_value(buf, info_local, floatval, &exponent)) < 0) {
+ 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;
+
+ sr_dbg("Returns SR_OK - parsing value: %d.", ret);
+
+ return SR_OK;
+}
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