/* * This file is part of the libsigrok project. * * Copyright (C) 2012-2013 Uwe Hermann * Copyright (C) 2018 Matthias Schulz * * 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 . */ /* * 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 #include #include #include #include #include #include #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; 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, "K")) info->is_kilo = TRUE; else if (!g_ascii_strcasecmp(u, "M")) info->is_mega = TRUE; else if (!g_ascii_strcasecmp(u, "")) info->is_unitless = TRUE; /* 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)) return FALSE; if ((buf[11] != '\r') || (buf[12] != '\n')) 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; return SR_OK; }