--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Copyright (C) 2018 Stefan Mandl
+ *
+ * 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/>.
+ */
+
+/*
+ * MASTECH MS8250D protocol parser.
+ *
+ * Sends 18 bytes.
+ * 40 02 32 75 53 33 35 5303 10 00 00 00 00 00 00 10 00
+ *
+ * - Communication parameters: Unidirectional, 2400/8n1
+ * - CP2102 USB to UART bridge controller
+ */
+
+#include <config.h>
+#include <string.h>
+#include <ctype.h>
+#include <math.h>
+#include <glib.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "ms8250d"
+
+/*
+ * Main display (7-segment LCD value): xxDGA xxEF xxxx xxCB
+ * https://en.wikipedia.org/wiki/Seven-segment_display
+ */
+static int parse_digit(uint16_t b)
+{
+ switch (b) {
+ case 0x0: /* 7-segment not active */
+ return 0;
+ case 0x430: /* Overflow */
+ return 0xF;
+ case 0x533:
+ return 0;
+ case 0x003:
+ return 1;
+ case 0x721:
+ return 2;
+ case 0x703:
+ return 3;
+ case 0x213:
+ return 4;
+ case 0x712:
+ return 5;
+ case 0x732:
+ return 6;
+ case 0x103:
+ return 7;
+ case 0x733:
+ return 8;
+ case 0x713:
+ return 9;
+ default:
+ sr_dbg("Invalid digit byte: 0x%02x.", b);
+ return -1;
+ }
+}
+
+/* Parse second display. */
+static int parse_digit2(uint16_t b)
+{
+ switch (b) {
+ case 0x00:
+ return 0;
+ case 0x7D:
+ return 0;
+ case 0x05:
+ return 1;
+ case 0x1B:
+ return 2;
+ case 0x1F:
+ return 3;
+ case 0x27:
+ return 4;
+ case 0x3E:
+ return 5;
+ case 0x7E:
+ return 6;
+ case 0x15:
+ return 7;
+ case 0x7F:
+ return 8;
+ case 0x3F:
+ return 9;
+ default:
+ sr_dbg("Invalid second display digit byte: 0x%02x.", b);
+ return -1;
+ }
+}
+
+static void parse_flags(const uint8_t *buf, struct ms8250d_info *info)
+{
+ info->is_volt = (buf[9] & (1 << 4)) ? 1 : 0;
+ info->is_ohm = (buf[9] & (1 << 6)) ? 1 : 0;
+ info->is_ampere = (buf[10] & (1 << 0)) ? 1 : 0;
+ info->is_hz = (buf[10] & (1 << 2)) ? 1 : 0;
+ info->is_farad = (buf[10] & (1 << 1)) ? 1 : 0;
+
+ /* Micro */
+ if (!info->is_farad)
+ info->is_micro = (buf[8] & (1 << 4)) ? 1 : 0;
+ else
+ info->is_micro = (buf[9] & (1 << 1)) ? 1 : 0; /* uF */
+
+ info->is_nano = (buf[8] & (1 << 5)) ? 1 : 0;
+ info->is_milli = (buf[9] & (1 << 0)) ? 1 : 0;
+ info->is_kilo = (buf[9] & (1 << 2)) ? 1 : 0;
+ info->is_mega = (buf[8] & (1 << 6)) ? 1 : 0;
+
+ info->is_autotimer = (buf[1] & (1 << 0)) ? 1 : 0; /* Auto off timer */
+ info->is_rs232 = (buf[1] & (1 << 1)) ? 1 : 0; /* RS232 via USB */
+ info->is_ac = (buf[1] & (1 << 4)) ? 1 : 0;
+ info->is_dc = (buf[2] & (1 << 1)) ? 1 : 0;
+ info->is_auto = (buf[16] & (1 << 4)) ? 1 : 0;
+ info->is_bat = (buf[1] & (1 << 5)) ? 1 : 0; /* Low battery */
+ info->is_min = (buf[16] & (1 << 2)) ? 1 : 0;
+ info->is_max = (buf[16] & (1 << 1)) ? 1 : 0;
+ info->is_rel = (buf[15] & (1 << 7)) ? 1 : 0;
+ info->is_hold = (buf[16] & (1 << 3)) ? 1 : 0;
+ info->is_diode = (buf[11] & (1 << 0)) ? 1 : 0;
+ info->is_beep = (buf[11] & (1 << 1)) ? 1 : 0;
+ info->is_ncv = (buf[0] & (1 << 0)) ? 1 : 0;
+}
+
+static gboolean flags_valid(const struct ms8250d_info *info)
+{
+ int count;
+
+ /* Does the packet have more than one multiplier? */
+ count = 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_hz) ? 1 : 0;
+ count += (info->is_ohm) ? 1 : 0;
+ count += (info->is_farad) ? 1 : 0;
+ count += (info->is_ampere) ? 1 : 0;
+ count += (info->is_volt) ? 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;
+ }
+
+ /* RS232 flag set? */
+ if (!info->is_rs232) {
+ sr_dbg("No RS232 flag detected in packet.");
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
+ int *exponent, const struct ms8250d_info *info)
+{
+ /* Factors */
+ if (info->is_nano)
+ *exponent -= 9;
+ if (info->is_micro)
+ *exponent -= 6;
+ if (info->is_milli)
+ *exponent -= 3;
+ if (info->is_kilo)
+ *exponent += 3;
+ if (info->is_mega)
+ *exponent += 6;
+ *floatval *= powf(10, *exponent);
+
+ /* 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_hz) {
+ 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_beep) {
+ analog->meaning->mq = SR_MQ_CONTINUITY;
+ analog->meaning->unit = SR_UNIT_BOOLEAN;
+ *floatval = (*floatval == INFINITY) ? 0.0 : 1.0;
+ }
+ if (info->is_diode) {
+ analog->meaning->mq = SR_MQ_VOLTAGE;
+ analog->meaning->unit = SR_UNIT_VOLT;
+ }
+ if (info->is_percent) {
+ analog->meaning->mq = SR_MQ_DUTY_CYCLE;
+ analog->meaning->unit = SR_UNIT_PERCENTAGE;
+ }
+
+ /* 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_auto)
+ analog->meaning->mqflags |= SR_MQFLAG_AUTORANGE;
+ if (info->is_diode)
+ analog->meaning->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
+ if (info->is_hold)
+ analog->meaning->mqflags |= SR_MQFLAG_HOLD;
+ if (info->is_rel)
+ analog->meaning->mqflags |= SR_MQFLAG_RELATIVE;
+
+ /* Other flags */
+ if (info->is_rs232)
+ sr_spew("RS232 enabled.");
+ if (info->is_bat)
+ sr_spew("Battery is low.");
+ if (info->is_beep)
+ sr_spew("Beep is active");
+}
+
+SR_PRIV gboolean sr_ms8250d_packet_valid(const uint8_t *buf)
+{
+ struct ms8250d_info info;
+
+ sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x "
+ "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
+ buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
+ buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13],
+ buf[14], buf[15], buf[16], buf[17]);
+
+ parse_flags(buf, &info);
+
+ if ((buf[17] == 0x00) && flags_valid(&info))
+ return TRUE;
+
+ return FALSE;
+}
+
+/**
+ * Parse a protocol packet.
+ *
+ * @param buf Buffer containing the 18-byte protocol packet. Must not be NULL.
+ * @param floatval Pointer to a float variable. That variable will contain the
+ * result value upon parsing success. 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 ms8250d_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_ms8250d_parse(const uint8_t *buf, float *floatval,
+ struct sr_datafeed_analog *analog, void *info)
+{
+ int exponent = 0, sec_exponent = 0, sign;
+ float sec_floatval;
+
+ /* buf[0] bar display. */
+ /* buf[1] bar display. */
+
+ /* Parse seven segment digit. */
+ int16_t digit4 = parse_digit(((buf[7] & 0x73) << 4) | (buf[8] & 0x3));
+
+ int16_t digit3 = parse_digit(((buf[6] & 0x07) << 8) | (buf[5] & 0x30) \
+ | ((buf[6] & 0x30) >> 4));
+
+ int16_t digit2 = parse_digit(((buf[4] & 0x73) << 4) | (buf[5] & 0x03));
+
+ int16_t digit1 = parse_digit(((buf[3] & 0x07) << 8) | (buf[2] & 0x30) \
+ | ((buf[3] & 0x30) >> 4));
+
+ sr_dbg("Digits: %d %d %d %d.", digit1, digit2, digit3, digit4);
+
+ /* Decimal point position. */
+ if ((buf[3] & (1 << 6)) != 0) {
+ exponent = -3;
+ sr_spew("Decimal point after first digit.");
+ } else if ((buf[5] & (1 << 6)) != 0) {
+ exponent = -2;
+ sr_spew("Decimal point after second digit.");
+ } else if ((buf[7] & (1 << 2)) != 0) {
+ exponent = -1;
+ sr_spew("Decimal point after third digit.");
+ } else {
+ exponent = 0;
+ sr_spew("No decimal point in the number.");
+ }
+
+ struct ms8250d_info *info_local;
+
+ info_local = info;
+
+ parse_flags(buf, info_local);
+
+ /* Sign */
+ sign = (buf[0] & (1 << 2)) ? -1 : 1;
+
+ /* Parse second display. */
+ int16_t sec_digit4 = parse_digit2(buf[12] & 0x7F);
+ int16_t sec_digit3 = parse_digit2(buf[13] & 0x7F);
+ int16_t sec_digit2 = parse_digit2(buf[14] & 0x7F);
+ int16_t sec_digit1 = parse_digit2(buf[15] & 0x7F);
+
+ sr_dbg("Digits (2nd display): %d %d %d %d.",
+ sec_digit1, sec_digit2, sec_digit3, sec_digit4);
+
+ /* Second display decimal point position. */
+ if ((buf[14] & (1 << 7)) != 0) {
+ sec_exponent = -3;
+ sr_spew("Sec decimal point after first digit.");
+ } else if ((buf[13] & (1 << 7)) != 0) {
+ sec_exponent = -2;
+ sr_spew("Sec decimal point after second digit.");
+ } else if ((buf[12] & (1 << 7)) != 0) {
+ sec_exponent = -1;
+ sr_spew("Sec decimal point after third digit.");
+ } else {
+ sec_exponent = 0;
+ sr_spew("Sec no decimal point in the number.");
+ }
+
+ *floatval = (double)((digit1 * 1000) + (digit2 * 100) + (digit3 * 10) + digit4);
+
+ sec_floatval = (double)(sec_digit1 * 1000) + (sec_digit2 * 100) + (sec_digit3 * 10) + sec_digit4;
+ sec_floatval *= powf(10, sec_exponent);
+
+ /* Apply sign. */
+ *floatval *= sign;
+
+ handle_flags(analog, floatval, &exponent, info_local);
+
+ /* Check for "OL". */
+ if (digit3 == 0x0F) {
+ sr_spew("Over limit.");
+ *floatval = INFINITY;
+ return SR_OK;
+ }
+
+ sr_spew("The display value is %f.", (double)*floatval);
+ sr_spew("The 2nd display value is %f.", sec_floatval);
+
+ analog->encoding->digits = -exponent;
+ analog->spec->spec_digits = -exponent;
+
+ return SR_OK;
+}
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