--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
+ * Copyright (C) 2019 Gerhard Sittig <gerhard.sittig@gmx.net>
+ *
+ * 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 3 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/>.
+ */
+
+/**
+ * @file
+ *
+ * Brymen BM86x serial protocol parser. The USB protocol (for the cable)
+ * and the packet description (for the meter) were retrieved from:
+ * http://brymen.com/product-html/Download2.html
+ * http://brymen.com/product-html/PD02BM860s_protocolDL.html
+ * http://brymen.com/product-html/images/DownloadList/ProtocolList/BM860-BM860s_List/BM860-BM860s-500000-count-dual-display-DMMs-protocol.pdf
+ */
+
+#include <config.h>
+#include <math.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+#include <string.h>
+
+#define LOG_PREFIX "brymen-bm86x"
+
+#ifdef HAVE_SERIAL_COMM
+SR_PRIV int sr_brymen_bm86x_packet_request(struct sr_serial_dev_inst *serial)
+{
+ static const uint8_t request[] = { 0x00, 0x00, 0x86, 0x66, };
+
+ serial_write_nonblocking(serial, request, sizeof(request));
+
+ return SR_OK;
+}
+#endif
+
+SR_PRIV gboolean sr_brymen_bm86x_packet_valid(const uint8_t *buf)
+{
+ /*
+ * "Model ID3" (3rd HID report, byte 3) is the only documented
+ * fixed value, and must be 0x86. All other positions either depend
+ * on the meter's function, or the measurement's value, or are not
+ * documented by the vendor (are marked as "don't care", no fixed
+ * values are listed). There is nothing else we can check reliably.
+ */
+ if (buf[19] != 0x86)
+ return FALSE;
+
+ return TRUE;
+}
+
+/*
+ * Data bytes in the DMM packet encode LCD segments in an unusual order
+ * (bgcdafe) and in an unusual position (bits 7:1 within the byte). The
+ * decimal point (bit 0) for one digit resides in the _next_ digit's byte.
+ *
+ * These routines convert LCD segments to characters, and a section of the
+ * DMM packet (which corresponds to the primary or secondary display) to
+ * the text representation of the measurement's value, before regular text
+ * to number conversion is applied. The first byte of the passed in block
+ * contains indicators, the value's digits start at the second byte.
+ */
+
+static char brymen_bm86x_parse_digit(uint8_t b)
+{
+ switch (b >> 1) {
+ /* Sign. */
+ case 0x20: return '-';
+ /* Decimal digits. */
+ case 0x5f: return '0';
+ case 0x50: return '1';
+ case 0x6d: return '2';
+ case 0x7c: return '3';
+ case 0x72: return '4';
+ case 0x3e: return '5';
+ case 0x3f: return '6';
+ case 0x54: return '7';
+ case 0x7f: return '8';
+ case 0x7e: return '9';
+ /* Temperature units. */
+ case 0x0f: return 'C';
+ case 0x27: return 'F';
+ /* OL condition, and diode mode. */
+ case 0x0b: return 'L';
+ case 0x79: return 'd';
+ case 0x10: return 'i';
+ case 0x39: return 'o';
+ /* Blank digit. */
+ case 0x00: return '\0';
+ /* Invalid or unknown segment combination. */
+ default:
+ sr_warn("Unknown encoding for digit: 0x%02x.", b);
+ return '\0';
+ }
+}
+
+static int brymen_bm86x_parse_digits(const uint8_t *pkt, size_t pktlen,
+ char *txtbuf, float *value, char *temp_unit, int *digits, int signflag)
+{
+ uint8_t byte;
+ char *txtptr, txtchar;
+ size_t pos;
+ int ret;
+
+ txtptr = txtbuf;
+ if (digits)
+ *digits = INT_MIN;
+
+ if (pkt[0] & signflag)
+ *txtptr++ = '-';
+ for (pos = 0; pos < pktlen; pos++) {
+ byte = pkt[1 + pos];
+ if (pos && pos < 5 && (byte & 0x01)) {
+ *txtptr++ = '.';
+ if (digits)
+ *digits = 0;
+ }
+ txtchar = brymen_bm86x_parse_digit(byte);
+ if (pos == 5 && (txtchar == 'C' || txtchar == 'F')) {
+ if (temp_unit)
+ *temp_unit = txtchar;
+ } else if (txtchar) {
+ *txtptr++ = txtchar;
+ if (digits)
+ (*digits)++;
+ }
+ }
+ *txtptr = '\0';
+
+ if (digits && *digits < 0)
+ *digits = 0;
+
+ ret = value ? sr_atof_ascii(txtbuf, value) : SR_OK;
+ if (ret != SR_OK) {
+ sr_dbg("invalid float string: '%s'", txtbuf);
+ return ret;
+ }
+
+ return SR_OK;
+}
+
+/*
+ * Extract the measurement value and its properties for one of the
+ * meter's displays from the DMM packet.
+ */
+static void brymen_bm86x_parse(const uint8_t *buf, float *floatval,
+ struct sr_datafeed_analog *analog, size_t ch_idx)
+{
+ char txtbuf[16], temp_unit;
+ int ret, digits, is_diode, over_limit, scale;
+ uint8_t ind1, ind15;
+
+ temp_unit = '\0';
+ if (ch_idx == 0) {
+ /*
+ * Main display. Note that _some_ of the second display's
+ * indicators are involved in the inspection of the _first_
+ * display's measurement value. So we have to get the
+ * second display's text buffer here, too.
+ */
+ (void)brymen_bm86x_parse_digits(&buf[9], 4, txtbuf,
+ NULL, NULL, NULL, 0);
+ is_diode = strcmp(txtbuf, "diod") == 0;
+ ret = brymen_bm86x_parse_digits(&buf[2], 6, txtbuf,
+ floatval, &temp_unit, &digits, 0x80);
+ over_limit = strstr(txtbuf, "0L") || strstr(txtbuf, "0.L");
+ if (ret != SR_OK && !over_limit)
+ return;
+
+ /* SI unit. */
+ if (buf[8] & 0x01) {
+ analog->meaning->mq = SR_MQ_VOLTAGE;
+ analog->meaning->unit = SR_UNIT_VOLT;
+ if (is_diode) {
+ analog->meaning->mqflags |= SR_MQFLAG_DIODE;
+ analog->meaning->mqflags |= SR_MQFLAG_DC;
+ }
+ } else if (buf[14] & 0x80) {
+ analog->meaning->mq = SR_MQ_CURRENT;
+ analog->meaning->unit = SR_UNIT_AMPERE;
+ } else if (buf[14] & 0x20) {
+ analog->meaning->mq = SR_MQ_CAPACITANCE;
+ analog->meaning->unit = SR_UNIT_FARAD;
+ } else if (buf[14] & 0x10) {
+ analog->meaning->mq = SR_MQ_CONDUCTANCE;
+ analog->meaning->unit = SR_UNIT_SIEMENS;
+ } else if (buf[15] & 0x01) {
+ analog->meaning->mq = SR_MQ_FREQUENCY;
+ analog->meaning->unit = SR_UNIT_HERTZ;
+ } else if (buf[10] & 0x01) {
+ analog->meaning->mq = SR_MQ_CONTINUITY;
+ analog->meaning->unit = SR_UNIT_OHM;
+ } else if (buf[15] & 0x10) {
+ analog->meaning->mq = SR_MQ_RESISTANCE;
+ analog->meaning->unit = SR_UNIT_OHM;
+ } else if (buf[15] & 0x02) {
+ analog->meaning->mq = SR_MQ_POWER;
+ analog->meaning->unit = SR_UNIT_DECIBEL_MW;
+ } else if (buf[15] & 0x80) {
+ analog->meaning->mq = SR_MQ_DUTY_CYCLE;
+ analog->meaning->unit = SR_UNIT_PERCENTAGE;
+ } else if ((buf[2] & 0x0a) && temp_unit) {
+ analog->meaning->mq = SR_MQ_TEMPERATURE;
+ if (temp_unit == 'F')
+ analog->meaning->unit = SR_UNIT_FAHRENHEIT;
+ else
+ analog->meaning->unit = SR_UNIT_CELSIUS;
+ }
+
+ /*
+ * Remove the MIN/MAX/AVG indicators when all of them
+ * are shown at the same time.
+ */
+ ind1 = buf[1];
+ if ((ind1 & 0xe0) == 0xe0)
+ ind1 &= ~0xe0;
+
+ /* AC/DC/Auto flags. */
+ if (buf[1] & 0x10)
+ analog->meaning->mqflags |= SR_MQFLAG_DC;
+ if (buf[2] & 0x01)
+ analog->meaning->mqflags |= SR_MQFLAG_AC;
+ if (buf[1] & 0x01)
+ analog->meaning->mqflags |= SR_MQFLAG_AUTORANGE;
+ if (buf[1] & 0x08)
+ analog->meaning->mqflags |= SR_MQFLAG_HOLD;
+ if (ind1 & 0x20)
+ analog->meaning->mqflags |= SR_MQFLAG_MAX;
+ if (ind1 & 0x40)
+ analog->meaning->mqflags |= SR_MQFLAG_MIN;
+ if (ind1 & 0x80)
+ analog->meaning->mqflags |= SR_MQFLAG_AVG;
+ if (buf[3] & 0x01)
+ analog->meaning->mqflags |= SR_MQFLAG_RELATIVE;
+
+ /*
+ * Remove the "dBm" indication's "m" indicator before the
+ * SI unit's prefixes get inspected. To avoid an interaction
+ * with the "milli" prefix.
+ */
+ ind15 = buf[15];
+ if (ind15 & 0x02)
+ ind15 &= ~0x04;
+
+ /* SI prefix. */
+ scale = 0;
+ if (buf[14] & 0x40) /* n */
+ scale = -9;
+ if (buf[15] & 0x08) /* u */
+ scale = -6;
+ if (ind15 & 0x04) /* m */
+ scale = -3;
+ if (buf[15] & 0x40) /* k */
+ scale = +3;
+ if (buf[15] & 0x20) /* M */
+ scale = +6;
+ if (scale) {
+ *floatval *= pow(10, scale);
+ digits += -scale;
+ }
+
+ if (over_limit)
+ *floatval = INFINITY;
+
+ analog->encoding->digits = digits;
+ analog->spec->spec_digits = digits;
+ } else if (ch_idx == 1) {
+ /*
+ * Secondary display. Also inspect _some_ primary display
+ * data, to determine the secondary display's validity.
+ */
+ (void)brymen_bm86x_parse_digits(&buf[2], 6, txtbuf,
+ NULL, &temp_unit, NULL, 0x80);
+ ret = brymen_bm86x_parse_digits(&buf[9], 4, txtbuf,
+ floatval, NULL, &digits, 0x10);
+
+ /* SI unit. */
+ if (buf[14] & 0x08) {
+ analog->meaning->mq = SR_MQ_VOLTAGE;
+ analog->meaning->unit = SR_UNIT_VOLT;
+ } else if (buf[9] & 0x04) {
+ analog->meaning->mq = SR_MQ_CURRENT;
+ analog->meaning->unit = SR_UNIT_AMPERE;
+ } else if (buf[9] & 0x08) {
+ analog->meaning->mq = SR_MQ_CURRENT;
+ analog->meaning->unit = SR_UNIT_PERCENTAGE;
+ } else if (buf[14] & 0x04) {
+ analog->meaning->mq = SR_MQ_FREQUENCY;
+ analog->meaning->unit = SR_UNIT_HERTZ;
+ } else if ((buf[9] & 0x40) && temp_unit) {
+ analog->meaning->mq = SR_MQ_TEMPERATURE;
+ if (temp_unit == 'F')
+ analog->meaning->unit = SR_UNIT_FAHRENHEIT;
+ else
+ analog->meaning->unit = SR_UNIT_CELSIUS;
+ }
+
+ /* AC flag. */
+ if (buf[9] & 0x20)
+ analog->meaning->mqflags |= SR_MQFLAG_AC;
+
+ /* SI prefix. */
+ scale = 0;
+ if (buf[ 9] & 0x01) /* u */
+ scale = -6;
+ if (buf[ 9] & 0x02) /* m */
+ scale = -3;
+ if (buf[14] & 0x02) /* k */
+ scale = +3;
+ if (buf[14] & 0x01) /* M */
+ scale = +6;
+ if (scale) {
+ *floatval *= pow(10, scale);
+ digits += -scale;
+ }
+
+ analog->encoding->digits = digits;
+ analog->spec->spec_digits = digits;
+ }
+
+ if (buf[9] & 0x80)
+ sr_warn("Battery is low.");
+}
+
+SR_PRIV int sr_brymen_bm86x_parse(const uint8_t *buf, float *val,
+ struct sr_datafeed_analog *analog, void *info)
+{
+ struct brymen_bm86x_info *info_local;
+ size_t ch_idx;
+
+ /*
+ * Scan a portion of the received DMM packet which corresponds
+ * to the caller's specified display. Then prepare to scan a
+ * different portion of the packet for another display. This
+ * routine gets called multiple times for one received packet.
+ */
+ info_local = info;
+ ch_idx = info_local->ch_idx;
+ brymen_bm86x_parse(buf, val, analog, ch_idx);
+ info_local->ch_idx = ch_idx + 1;
+
+ return SR_OK;
+}
projects / libsigrok.git / blobdiff