2 * This file is part of the libsigrok project.
4 * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
5 * Copyright (C) 2019 Gerhard Sittig <gerhard.sittig@gmx.net>
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 * Brymen BM86x serial protocol parser. The USB protocol (for the cable)
25 * and the packet description (for the meter) were retrieved from:
26 * http://brymen.com/product-html/Download2.html
27 * http://brymen.com/product-html/PD02BM860s_protocolDL.html
28 * http://brymen.com/product-html/images/DownloadList/ProtocolList/BM860-BM860s_List/BM860-BM860s-500000-count-dual-display-DMMs-protocol.pdf
33 #include <libsigrok/libsigrok.h>
34 #include "libsigrok-internal.h"
37 #define LOG_PREFIX "brymen-bm86x"
39 #ifdef HAVE_SERIAL_COMM
40 SR_PRIV int sr_brymen_bm86x_packet_request(struct sr_serial_dev_inst *serial)
42 static const uint8_t request[] = { 0x00, 0x00, 0x86, 0x66, };
44 sr_spew("%s() sending request", __func__);
45 serial_write_nonblocking(serial, request, sizeof(request));
51 SR_PRIV gboolean sr_brymen_bm86x_packet_valid(const uint8_t *buf)
55 if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
56 text = sr_hexdump_new(buf, BRYMEN_BM86X_PACKET_SIZE);
57 sr_spew("%s() checking DMM packet: %s", __func__, text->str);
58 sr_hexdump_free(text);
62 * "Model ID3" (3rd HID report, byte 3) is the only documented
63 * fixed value, and must be 0x86. All other positions either depend
64 * on the meter's function, or the measurement's value, or are not
65 * documented by the vendor (are marked as "don't care", no fixed
66 * values are listed). There is nothing else we can check reliably.
75 * Data bytes in the DMM packet encode LCD segments in an unusual order
76 * (bgcdafe) and in an unusual position (bits 7:1 within the byte). The
77 * decimal point (bit 0) for one digit resides in the _next_ digit's byte.
79 * These routines convert LCD segments to characters, and a section of the
80 * DMM packet (which corresponds to the primary or secondary display) to
81 * the text representation of the measurement's value, before regular text
82 * to number conversion is applied. The first byte of the passed in block
83 * contains indicators, the value's digits start at the second byte.
86 static char brymen_bm86x_parse_digit(uint8_t b)
90 case 0x20: return '-';
92 case 0x5f: return '0';
93 case 0x50: return '1';
94 case 0x6d: return '2';
95 case 0x7c: return '3';
96 case 0x72: return '4';
97 case 0x3e: return '5';
98 case 0x3f: return '6';
99 case 0x54: return '7';
100 case 0x7f: return '8';
101 case 0x7e: return '9';
102 /* Temperature units. */
103 case 0x0f: return 'C';
104 case 0x27: return 'F';
105 /* OL condition, and diode mode. */
106 case 0x0b: return 'L';
107 case 0x79: return 'd';
108 case 0x10: return 'i';
109 case 0x39: return 'o';
111 case 0x00: return '\0';
112 /* Invalid or unknown segment combination. */
114 sr_warn("Unknown encoding for digit: 0x%02x.", b);
119 static int brymen_bm86x_parse_digits(const uint8_t *pkt, size_t pktlen,
120 char *txtbuf, float *value, char *temp_unit, int *digits, int signflag)
123 char *txtptr, txtchar;
131 if (pkt[0] & signflag)
133 for (pos = 0; pos < pktlen; pos++) {
135 if (pos && pos < 5 && (byte & 0x01)) {
140 txtchar = brymen_bm86x_parse_digit(byte);
141 if (pos == 5 && (txtchar == 'C' || txtchar == 'F')) {
143 *temp_unit = txtchar;
144 } else if (txtchar) {
152 if (digits && *digits < 0)
155 ret = value ? sr_atof_ascii(txtbuf, value) : SR_OK;
157 sr_dbg("invalid float string: '%s'", txtbuf);
165 * Extract the measurement value and its properties for one of the
166 * meter's displays from the DMM packet.
168 static void brymen_bm86x_parse(const uint8_t *buf, float *floatval,
169 struct sr_datafeed_analog *analog, size_t ch_idx)
171 char txtbuf[16], temp_unit;
172 int ret, digits, is_diode, over_limit, scale;
177 * Main display. Note that _some_ of the second display's
178 * indicators are involved in the inspection of the _first_
179 * display's measurement value. So we have to get the
180 * second display's text buffer here, too.
182 (void)brymen_bm86x_parse_digits(&buf[9], 4, txtbuf,
183 NULL, NULL, NULL, 0);
184 is_diode = strcmp(txtbuf, "diod") == 0;
185 ret = brymen_bm86x_parse_digits(&buf[2], 6, txtbuf,
186 floatval, &temp_unit, &digits, 0x80);
187 over_limit = strstr(txtbuf, "0L") || strstr(txtbuf, "0.L");
188 if (ret != SR_OK && !over_limit)
193 analog->meaning->mq = SR_MQ_VOLTAGE;
194 analog->meaning->unit = SR_UNIT_VOLT;
196 analog->meaning->mqflags |= SR_MQFLAG_DIODE;
197 analog->meaning->mqflags |= SR_MQFLAG_DC;
199 } else if (buf[14] & 0x80) {
200 analog->meaning->mq = SR_MQ_CURRENT;
201 analog->meaning->unit = SR_UNIT_AMPERE;
202 } else if (buf[14] & 0x20) {
203 analog->meaning->mq = SR_MQ_CAPACITANCE;
204 analog->meaning->unit = SR_UNIT_FARAD;
205 } else if (buf[14] & 0x10) {
206 analog->meaning->mq = SR_MQ_CONDUCTANCE;
207 analog->meaning->unit = SR_UNIT_SIEMENS;
208 } else if (buf[15] & 0x01) {
209 analog->meaning->mq = SR_MQ_FREQUENCY;
210 analog->meaning->unit = SR_UNIT_HERTZ;
211 } else if (buf[10] & 0x01) {
212 analog->meaning->mq = SR_MQ_CONTINUITY;
213 analog->meaning->unit = SR_UNIT_OHM;
214 } else if (buf[15] & 0x10) {
215 analog->meaning->mq = SR_MQ_RESISTANCE;
216 analog->meaning->unit = SR_UNIT_OHM;
217 } else if (buf[15] & 0x02) {
218 analog->meaning->mq = SR_MQ_POWER;
219 analog->meaning->unit = SR_UNIT_DECIBEL_MW;
220 } else if (buf[15] & 0x80) {
221 analog->meaning->mq = SR_MQ_DUTY_CYCLE;
222 analog->meaning->unit = SR_UNIT_PERCENTAGE;
223 } else if (buf[ 2] & 0x0a) {
224 analog->meaning->mq = SR_MQ_TEMPERATURE;
225 if (temp_unit == 'F')
226 analog->meaning->unit = SR_UNIT_FAHRENHEIT;
228 analog->meaning->unit = SR_UNIT_CELSIUS;
232 * Remove the MIN/MAX/AVG indicators when all of them
233 * are shown at the same time.
236 if ((ind1 & 0xe0) == 0xe0)
239 /* AC/DC/Auto flags. */
241 analog->meaning->mqflags |= SR_MQFLAG_DC;
243 analog->meaning->mqflags |= SR_MQFLAG_AC;
245 analog->meaning->mqflags |= SR_MQFLAG_AUTORANGE;
247 analog->meaning->mqflags |= SR_MQFLAG_HOLD;
249 analog->meaning->mqflags |= SR_MQFLAG_MAX;
251 analog->meaning->mqflags |= SR_MQFLAG_MIN;
253 analog->meaning->mqflags |= SR_MQFLAG_AVG;
255 analog->meaning->mqflags |= SR_MQFLAG_RELATIVE;
258 * Remove the "dBm" indication's "m" indicator before the
259 * SI unit's prefixes get inspected. To avoid an interaction
260 * with the "milli" prefix.
268 if (buf[14] & 0x40) /* n */
270 if (buf[15] & 0x08) /* u */
272 if (ind15 & 0x04) /* m */
274 if (buf[15] & 0x40) /* k */
276 if (buf[15] & 0x20) /* M */
279 *floatval *= pow(10, scale);
284 *floatval = INFINITY;
286 analog->encoding->digits = digits;
287 analog->spec->spec_digits = digits;
288 } else if (ch_idx == 1) {
289 /* Secondary display. */
290 ret = brymen_bm86x_parse_digits(&buf[9], 4, txtbuf,
291 floatval, &temp_unit, &digits, 0x10);
294 if (buf[14] & 0x08) {
295 analog->meaning->mq = SR_MQ_VOLTAGE;
296 analog->meaning->unit = SR_UNIT_VOLT;
297 } else if (buf[9] & 0x04) {
298 analog->meaning->mq = SR_MQ_CURRENT;
299 analog->meaning->unit = SR_UNIT_AMPERE;
300 } else if (buf[9] & 0x08) {
301 analog->meaning->mq = SR_MQ_CURRENT;
302 analog->meaning->unit = SR_UNIT_PERCENTAGE;
303 } else if (buf[14] & 0x04) {
304 analog->meaning->mq = SR_MQ_FREQUENCY;
305 analog->meaning->unit = SR_UNIT_HERTZ;
306 } else if (buf[9] & 0x40) {
307 analog->meaning->mq = SR_MQ_TEMPERATURE;
308 if (temp_unit == 'F')
309 analog->meaning->unit = SR_UNIT_FAHRENHEIT;
311 analog->meaning->unit = SR_UNIT_CELSIUS;
316 analog->meaning->mqflags |= SR_MQFLAG_AC;
320 if (buf[ 9] & 0x01) /* u */
322 if (buf[ 9] & 0x02) /* m */
324 if (buf[14] & 0x02) /* k */
326 if (buf[14] & 0x01) /* M */
329 *floatval *= pow(10, scale);
333 analog->encoding->digits = digits;
334 analog->spec->spec_digits = digits;
338 sr_warn("Battery is low.");
341 SR_PRIV int sr_brymen_bm86x_parse(const uint8_t *buf, float *val,
342 struct sr_datafeed_analog *analog, void *info)
344 struct brymen_bm86x_info *info_local;
348 * Scan a portion of the received DMM packet which corresponds
349 * to the caller's specified display. Then prepare to scan a
350 * different portion of the packet for another display. This
351 * routine gets called multiple times for one received packet.
354 ch_idx = info_local->ch_idx;
355 brymen_bm86x_parse(buf, val, analog, ch_idx);
356 info_local->ch_idx = ch_idx + 1;