[libsigrok.git] / src / dmm / bm86x.c

/*
 * 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, };

	sr_spew("%s() sending request", __func__);
	serial_write_nonblocking(serial, request, sizeof(request));

	return SR_OK;
}
#endif

SR_PRIV gboolean sr_brymen_bm86x_packet_valid(const uint8_t *buf)
{
	GString *text;

	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
		text = sr_hexdump_new(buf, BRYMEN_BM86X_PACKET_SIZE);
		sr_spew("%s() checking DMM packet: %s", __func__, text->str);
		sr_hexdump_free(text);
	}

	/*
	 * "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;

	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) {
			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. */
		ret = brymen_bm86x_parse_digits(&buf[9], 4, txtbuf,
			floatval, &temp_unit, &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) {
			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;
}
Commit	Line	Data
0759e2f5 GS	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
	5	* Copyright (C) 2019 Gerhard Sittig <gerhard.sittig@gmx.net>
	6	*
	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.
	11	*
	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.
	16	*
	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/>.
	19	*/
	20
	21	/**
	22	* @file
	23	*
	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
	29	*/
	30
	31	#include <config.h>
	32	#include <math.h>
	33	#include <libsigrok/libsigrok.h>
	34	#include "libsigrok-internal.h"
	35	#include <string.h>
	36
	37	#define LOG_PREFIX "brymen-bm86x"
	38
	39	#ifdef HAVE_SERIAL_COMM
	40	SR_PRIV int sr_brymen_bm86x_packet_request(struct sr_serial_dev_inst *serial)
	41	{
	42	static const uint8_t request[] = { 0x00, 0x00, 0x86, 0x66, };
	43
	44	sr_spew("%s() sending request", __func__);
	45	serial_write_nonblocking(serial, request, sizeof(request));
	46
	47	return SR_OK;
	48	}
	49	#endif
	50
	51	SR_PRIV gboolean sr_brymen_bm86x_packet_valid(const uint8_t *buf)
	52	{
	53	GString *text;
	54
	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);
	59	}
	60
	61	/*
	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.
67	*/
68	if (buf[19] != 0x86)
69	return FALSE;
70
71	return TRUE;
72	}
73
74	/*
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.
78	*
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.
84	*/
85
86	static char brymen_bm86x_parse_digit(uint8_t b)
87	{
88	switch (b >> 1) {
89	/* Sign. */
90	case 0x20: return '-';
91	/* Decimal digits. */
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';
110	/* Blank digit. */
111	case 0x00: return '\0';
112	/* Invalid or unknown segment combination. */
113	default:
114	sr_warn("Unknown encoding for digit: 0x%02x.", b);
115	return '\0';
116	}
117	}
118
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)
121	{
122	uint8_t byte;
123	char *txtptr, txtchar;
124	size_t pos;
125	int ret;
126
127	txtptr = txtbuf;
128	if (digits)
129	*digits = INT_MIN;
130
131	if (pkt[0] & signflag)
132	*txtptr++ = '-';
133	for (pos = 0; pos < pktlen; pos++) {
134	byte = pkt[1 + pos];
135	if (pos && pos < 5 && (byte & 0x01)) {
136	*txtptr++ = '.';
137	if (digits)
138	*digits = 0;
139	}
140	txtchar = brymen_bm86x_parse_digit(byte);
141	if (pos == 5 && (txtchar == 'C' \|\| txtchar == 'F')) {
142	if (temp_unit)
143	*temp_unit = txtchar;
144	} else if (txtchar) {
145	*txtptr++ = txtchar;
146	if (digits)
147	(*digits)++;
148	}
149	}
150	*txtptr = '\0';
151
152	if (digits && *digits < 0)
153	*digits = 0;
154
155	ret = value ? sr_atof_ascii(txtbuf, value) : SR_OK;
156	if (ret != SR_OK) {
157	sr_dbg("invalid float string: '%s'", txtbuf);
158	return ret;
159	}
160
161	return SR_OK;
162	}
163
164	/*
165	* Extract the measurement value and its properties for one of the
166	* meter's displays from the DMM packet.
167	*/
168	static void brymen_bm86x_parse(const uint8_t buf, float floatval,
169	struct sr_datafeed_analog *analog, size_t ch_idx)
170	{
171	char txtbuf[16], temp_unit;
172	int ret, digits, is_diode, over_limit, scale;
173	uint8_t ind1, ind15;
174
175	if (ch_idx == 0) {
176	/*
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.
181	*/
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)
189	return;
190
191	/* SI unit. */
192	if (buf[8] & 0x01) {
193	analog->meaning->mq = SR_MQ_VOLTAGE;
194	analog->meaning->unit = SR_UNIT_VOLT;
195	if (is_diode) {
196	analog->meaning->mqflags \|= SR_MQFLAG_DIODE;
197	analog->meaning->mqflags \|= SR_MQFLAG_DC;
198	}
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;
227	else
228	analog->meaning->unit = SR_UNIT_CELSIUS;
229	}
230
231	/*
232	* Remove the MIN/MAX/AVG indicators when all of them
233	* are shown at the same time.
234	*/
235	ind1 = buf[1];
236	if ((ind1 & 0xe0) == 0xe0)
237	ind1 &= ~0xe0;
238
239	/* AC/DC/Auto flags. */
240	if (buf[1] & 0x10)
241	analog->meaning->mqflags \|= SR_MQFLAG_DC;
242	if (buf[2] & 0x01)
243	analog->meaning->mqflags \|= SR_MQFLAG_AC;
244	if (buf[1] & 0x01)
245	analog->meaning->mqflags \|= SR_MQFLAG_AUTORANGE;
246	if (buf[1] & 0x08)
247	analog->meaning->mqflags \|= SR_MQFLAG_HOLD;
248	if (ind1 & 0x20)
249	analog->meaning->mqflags \|= SR_MQFLAG_MAX;
250	if (ind1 & 0x40)
251	analog->meaning->mqflags \|= SR_MQFLAG_MIN;
252	if (ind1 & 0x80)
253	analog->meaning->mqflags \|= SR_MQFLAG_AVG;
254	if (buf[3] & 0x01)
255	analog->meaning->mqflags \|= SR_MQFLAG_RELATIVE;
256
257	/*
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.
261	*/
262	ind15 = buf[15];
263	if (ind15 & 0x02)
264	ind15 &= ~0x04;
265
266	/* SI prefix. */
267	scale = 0;
268	if (buf[14] & 0x40) /* n */
269	scale = -9;
270	if (buf[15] & 0x08) /* u */
271	scale = -6;
272	if (ind15 & 0x04) /* m */
273	scale = -3;
274	if (buf[15] & 0x40) /* k */
275	scale = +3;
276	if (buf[15] & 0x20) /* M */
277	scale = +6;
278	if (scale) {
279	floatval = pow(10, scale);
280	digits += -scale;
281	}
282
283	if (over_limit)
284	*floatval = INFINITY;
285
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);
292
293	/* SI unit. */
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;
310	else
311	analog->meaning->unit = SR_UNIT_CELSIUS;
312	}
313
314	/* AC flag. */
315	if (buf[9] & 0x20)
316	analog->meaning->mqflags \|= SR_MQFLAG_AC;
317
318	/* SI prefix. */
319	scale = 0;
320	if (buf[ 9] & 0x01) /* u */
321	scale = -6;
322	if (buf[ 9] & 0x02) /* m */
323	scale = -3;
324	if (buf[14] & 0x02) /* k */
325	scale = +3;
326	if (buf[14] & 0x01) /* M */
327	scale = +6;
328	if (scale) {
329	floatval = pow(10, scale);
330	digits += -scale;
331	}
332
333	analog->encoding->digits = digits;
334	analog->spec->spec_digits = digits;
335	}
336
337	if (buf[9] & 0x80)
338	sr_warn("Battery is low.");
339	}
340
341	SR_PRIV int sr_brymen_bm86x_parse(const uint8_t buf, float val,
342	struct sr_datafeed_analog analog, void info)
343	{
344	struct brymen_bm86x_info *info_local;
345	size_t ch_idx;
346
347	/*
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.
352	*/
353	info_local = info;
354	ch_idx = info_local->ch_idx;
355	brymen_bm86x_parse(buf, val, analog, ch_idx);
356	info_local->ch_idx = ch_idx + 1;
357
358	return SR_OK;
359	}