[libsigrok.git] / src / dmm / ms8250d.c

/*
 * 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 word: 0x%04x.", 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 word: 0x%04x.", 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;
}
Commit	Line	Data
67070942 M	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
	5	* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
	6	* Copyright (C) 2018 Stefan Mandl
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	20	*/
	21
	22	/*
	23	* MASTECH MS8250D protocol parser.
	24	*
	25	* Sends 18 bytes.
	26	* 40 02 32 75 53 33 35 5303 10 00 00 00 00 00 00 10 00
	27	*
	28	* - Communication parameters: Unidirectional, 2400/8n1
	29	* - CP2102 USB to UART bridge controller
	30	*/
	31
	32	#include <config.h>
	33	#include <string.h>
	34	#include <ctype.h>
	35	#include <math.h>
	36	#include <glib.h>
	37	#include <libsigrok/libsigrok.h>
	38	#include "libsigrok-internal.h"
	39
	40	#define LOG_PREFIX "ms8250d"
	41
	42	/*
	43	* Main display (7-segment LCD value): xxDGA xxEF xxxx xxCB
	44	* https://en.wikipedia.org/wiki/Seven-segment_display
	45	*/
	46	static int parse_digit(uint16_t b)
	47	{
	48	switch (b) {
	49	case 0x0: /* 7-segment not active */
	50	return 0;
	51	case 0x430: /* Overflow */
	52	return 0xF;
	53	case 0x533:
	54	return 0;
	55	case 0x003:
	56	return 1;
	57	case 0x721:
	58	return 2;
	59	case 0x703:
	60	return 3;
	61	case 0x213:
	62	return 4;
	63	case 0x712:
	64	return 5;
65	case 0x732:
66	return 6;
67	case 0x103:
68	return 7;
69	case 0x733:
70	return 8;
71	case 0x713:
72	return 9;
73	default:
8a14fc08	74	sr_dbg("Invalid digit word: 0x%04x.", b);
67070942 M	75	return -1;
	76	}
	77	}
	78
	79	/* Parse second display. */
	80	static int parse_digit2(uint16_t b)
	81	{
	82	switch (b) {
	83	case 0x00:
	84	return 0;
	85	case 0x7D:
	86	return 0;
	87	case 0x05:
	88	return 1;
	89	case 0x1B:
	90	return 2;
	91	case 0x1F:
	92	return 3;
	93	case 0x27:
	94	return 4;
	95	case 0x3E:
	96	return 5;
	97	case 0x7E:
	98	return 6;
	99	case 0x15:
	100	return 7;
	101	case 0x7F:
	102	return 8;
	103	case 0x3F:
	104	return 9;
	105	default:
8a14fc08	106	sr_dbg("Invalid second display digit word: 0x%04x.", b);
67070942 M	107	return -1;
	108	}
	109	}
	110
	111	static void parse_flags(const uint8_t buf, struct ms8250d_info info)
	112	{
	113	info->is_volt = (buf[9] & (1 << 4)) ? 1 : 0;
	114	info->is_ohm = (buf[9] & (1 << 6)) ? 1 : 0;
	115	info->is_ampere = (buf[10] & (1 << 0)) ? 1 : 0;
	116	info->is_hz = (buf[10] & (1 << 2)) ? 1 : 0;
	117	info->is_farad = (buf[10] & (1 << 1)) ? 1 : 0;
	118
	119	/* Micro */
	120	if (!info->is_farad)
	121	info->is_micro = (buf[8] & (1 << 4)) ? 1 : 0;
	122	else
	123	info->is_micro = (buf[9] & (1 << 1)) ? 1 : 0; /* uF */
	124
	125	info->is_nano = (buf[8] & (1 << 5)) ? 1 : 0;
	126	info->is_milli = (buf[9] & (1 << 0)) ? 1 : 0;
	127	info->is_kilo = (buf[9] & (1 << 2)) ? 1 : 0;
	128	info->is_mega = (buf[8] & (1 << 6)) ? 1 : 0;
	129
	130	info->is_autotimer = (buf[1] & (1 << 0)) ? 1 : 0; /* Auto off timer */
	131	info->is_rs232 = (buf[1] & (1 << 1)) ? 1 : 0; /* RS232 via USB */
	132	info->is_ac = (buf[1] & (1 << 4)) ? 1 : 0;
	133	info->is_dc = (buf[2] & (1 << 1)) ? 1 : 0;
	134	info->is_auto = (buf[16] & (1 << 4)) ? 1 : 0;
	135	info->is_bat = (buf[1] & (1 << 5)) ? 1 : 0; /* Low battery */
	136	info->is_min = (buf[16] & (1 << 2)) ? 1 : 0;
	137	info->is_max = (buf[16] & (1 << 1)) ? 1 : 0;
	138	info->is_rel = (buf[15] & (1 << 7)) ? 1 : 0;
	139	info->is_hold = (buf[16] & (1 << 3)) ? 1 : 0;
	140	info->is_diode = (buf[11] & (1 << 0)) ? 1 : 0;
	141	info->is_beep = (buf[11] & (1 << 1)) ? 1 : 0;
	142	info->is_ncv = (buf[0] & (1 << 0)) ? 1 : 0;
	143	}
	144
	145	static gboolean flags_valid(const struct ms8250d_info *info)
	146	{
	147	int count;
	148
	149	/* Does the packet have more than one multiplier? */
	150	count = 0;
	151	count += (info->is_nano) ? 1 : 0;
	152	count += (info->is_micro) ? 1 : 0;
	153	count += (info->is_milli) ? 1 : 0;
	154	count += (info->is_kilo) ? 1 : 0;
	155	count += (info->is_mega) ? 1 : 0;
	156	if (count > 1) {
	157	sr_dbg("More than one multiplier detected in packet.");
	158	return FALSE;
	159	}
	160
	161	/* Does the packet "measure" more than one type of value? */
	162	count = 0;
	163	count += (info->is_hz) ? 1 : 0;
	164	count += (info->is_ohm) ? 1 : 0;
	165	count += (info->is_farad) ? 1 : 0;
	166	count += (info->is_ampere) ? 1 : 0;
	167	count += (info->is_volt) ? 1 : 0;
	168	if (count > 1) {
	169	sr_dbg("More than one measurement type detected in packet.");
	170	return FALSE;
171	}
172
173	/* Both AC and DC set? */
174	if (info->is_ac && info->is_dc) {
175	sr_dbg("Both AC and DC flags detected in packet.");
176	return FALSE;
177	}
178
179	/* RS232 flag set? */
180	if (!info->is_rs232) {
181	sr_dbg("No RS232 flag detected in packet.");
182	return FALSE;
183	}
184
185	return TRUE;
186	}
187
188	static void handle_flags(struct sr_datafeed_analog analog, float floatval,
189	int exponent, const struct ms8250d_info info)
190	{
191	/* Factors */
192	if (info->is_nano)
193	*exponent -= 9;
194	if (info->is_micro)
195	*exponent -= 6;
196	if (info->is_milli)
197	*exponent -= 3;
198	if (info->is_kilo)
199	*exponent += 3;
200	if (info->is_mega)
201	*exponent += 6;
202	floatval = powf(10, *exponent);
203
204	/* Measurement modes */
205	if (info->is_volt) {
206	analog->meaning->mq = SR_MQ_VOLTAGE;
207	analog->meaning->unit = SR_UNIT_VOLT;
208	}
209	if (info->is_ampere) {
210	analog->meaning->mq = SR_MQ_CURRENT;
211	analog->meaning->unit = SR_UNIT_AMPERE;
212	}
213	if (info->is_ohm) {
214	analog->meaning->mq = SR_MQ_RESISTANCE;
215	analog->meaning->unit = SR_UNIT_OHM;
216	}
217	if (info->is_hz) {
218	analog->meaning->mq = SR_MQ_FREQUENCY;
219	analog->meaning->unit = SR_UNIT_HERTZ;
220	}
221	if (info->is_farad) {
222	analog->meaning->mq = SR_MQ_CAPACITANCE;
223	analog->meaning->unit = SR_UNIT_FARAD;
224	}
225	if (info->is_beep) {
226	analog->meaning->mq = SR_MQ_CONTINUITY;
227	analog->meaning->unit = SR_UNIT_BOOLEAN;
228	floatval = (floatval == INFINITY) ? 0.0 : 1.0;
229	}
230	if (info->is_diode) {
231	analog->meaning->mq = SR_MQ_VOLTAGE;
232	analog->meaning->unit = SR_UNIT_VOLT;
233	}
234	if (info->is_percent) {
235	analog->meaning->mq = SR_MQ_DUTY_CYCLE;
236	analog->meaning->unit = SR_UNIT_PERCENTAGE;
237	}
238
239	/* Measurement related flags */
240	if (info->is_ac)
241	analog->meaning->mqflags \|= SR_MQFLAG_AC;
242	if (info->is_dc)
243	analog->meaning->mqflags \|= SR_MQFLAG_DC;
244	if (info->is_auto)
245	analog->meaning->mqflags \|= SR_MQFLAG_AUTORANGE;
246	if (info->is_diode)
247	analog->meaning->mqflags \|= SR_MQFLAG_DIODE \| SR_MQFLAG_DC;
248	if (info->is_hold)
249	analog->meaning->mqflags \|= SR_MQFLAG_HOLD;
250	if (info->is_rel)
251	analog->meaning->mqflags \|= SR_MQFLAG_RELATIVE;
252
253	/* Other flags */
254	if (info->is_rs232)
255	sr_spew("RS232 enabled.");
256	if (info->is_bat)
257	sr_spew("Battery is low.");
258	if (info->is_beep)
259	sr_spew("Beep is active");
260	}
261
262	SR_PRIV gboolean sr_ms8250d_packet_valid(const uint8_t *buf)
263	{
264	struct ms8250d_info info;
265
266	sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x "
267	"%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
268	buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
269	buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13],
270	buf[14], buf[15], buf[16], buf[17]);
271
272	parse_flags(buf, &info);
273
274	if ((buf[17] == 0x00) && flags_valid(&info))
275	return TRUE;
276
277	return FALSE;
278	}
279
280	/**
281	* Parse a protocol packet.
282	*
283	* @param buf Buffer containing the 18-byte protocol packet. Must not be NULL.
284	* @param floatval Pointer to a float variable. That variable will contain the
285	* result value upon parsing success. Must not be NULL.
286	* @param analog Pointer to a struct sr_datafeed_analog. The struct will be
287	* filled with data according to the protocol packet.
288	* Must not be NULL.
289	* @param info Pointer to a struct ms8250d_info. The struct will be filled
290	* with data according to the protocol packet. Must not be NULL.
291	*
292	* @return SR_OK upon success, SR_ERR upon failure. Upon errors, the
293	* 'analog' variable contents are undefined and should not be used.
294	*/
295	SR_PRIV int sr_ms8250d_parse(const uint8_t buf, float floatval,
296	struct sr_datafeed_analog analog, void info)
297	{
298	int exponent = 0, sec_exponent = 0, sign;
299	float sec_floatval;
300
301	/* buf[0] bar display. */
302	/* buf[1] bar display. */
303
304	/* Parse seven segment digit. */
305	int16_t digit4 = parse_digit(((buf[7] & 0x73) << 4) \| (buf[8] & 0x3));
306
307	int16_t digit3 = parse_digit(((buf[6] & 0x07) << 8) \| (buf[5] & 0x30) \
308	\| ((buf[6] & 0x30) >> 4));
309
310	int16_t digit2 = parse_digit(((buf[4] & 0x73) << 4) \| (buf[5] & 0x03));
311
312	int16_t digit1 = parse_digit(((buf[3] & 0x07) << 8) \| (buf[2] & 0x30) \
313	\| ((buf[3] & 0x30) >> 4));
314
315	sr_dbg("Digits: %d %d %d %d.", digit1, digit2, digit3, digit4);
316
317	/* Decimal point position. */
318	if ((buf[3] & (1 << 6)) != 0) {
319	exponent = -3;
320	sr_spew("Decimal point after first digit.");
321	} else if ((buf[5] & (1 << 6)) != 0) {
322	exponent = -2;
323	sr_spew("Decimal point after second digit.");
324	} else if ((buf[7] & (1 << 2)) != 0) {
325	exponent = -1;
326	sr_spew("Decimal point after third digit.");
327	} else {
328	exponent = 0;
329	sr_spew("No decimal point in the number.");
330	}
331
332	struct ms8250d_info *info_local;
333
334	info_local = info;
335
336	parse_flags(buf, info_local);
337
338	/* Sign */
339	sign = (buf[0] & (1 << 2)) ? -1 : 1;
340
341	/* Parse second display. */
342	int16_t sec_digit4 = parse_digit2(buf[12] & 0x7F);
343	int16_t sec_digit3 = parse_digit2(buf[13] & 0x7F);
344	int16_t sec_digit2 = parse_digit2(buf[14] & 0x7F);
345	int16_t sec_digit1 = parse_digit2(buf[15] & 0x7F);
346
347	sr_dbg("Digits (2nd display): %d %d %d %d.",
348	sec_digit1, sec_digit2, sec_digit3, sec_digit4);
349
350	/* Second display decimal point position. */
351	if ((buf[14] & (1 << 7)) != 0) {
352	sec_exponent = -3;
353	sr_spew("Sec decimal point after first digit.");
354	} else if ((buf[13] & (1 << 7)) != 0) {
355	sec_exponent = -2;
356	sr_spew("Sec decimal point after second digit.");
357	} else if ((buf[12] & (1 << 7)) != 0) {
358	sec_exponent = -1;
359	sr_spew("Sec decimal point after third digit.");
360	} else {
361	sec_exponent = 0;
362	sr_spew("Sec no decimal point in the number.");
363	}
364
365	floatval = (double)((digit1 1000) + (digit2 * 100) + (digit3 * 10) + digit4);
366
367	sec_floatval = (double)(sec_digit1 * 1000) + (sec_digit2 * 100) + (sec_digit3 * 10) + sec_digit4;
368	sec_floatval *= powf(10, sec_exponent);
369
370	/* Apply sign. */
371	floatval = sign;
372
373	handle_flags(analog, floatval, &exponent, info_local);
374
375	/* Check for "OL". */
376	if (digit3 == 0x0F) {
377	sr_spew("Over limit.");
378	*floatval = INFINITY;
379	return SR_OK;
380	}
381
382	sr_spew("The display value is %f.", (double)*floatval);
383	sr_spew("The 2nd display value is %f.", sec_floatval);
384
385	analog->encoding->digits = -exponent;
386	analog->spec->spec_digits = -exponent;
387
388	return SR_OK;
389	}