[libsigrok.git] / src / dmm / ut372.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2015 Martin Ling <martin-sigrok@earth.li>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

/*
 * UNI-T UT372 protocol parser.
 */

#include <stdlib.h>
#include <stdint.h>
#include <math.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"

#define LOG_PREFIX "ut372"

uint8_t lookup[] = {
	0x7B,
	0x60,
	0x5E,
	0x7C,
	0x65,
	0x3D,
	0x3F,
	0x70,
	0x7F,
	0x7D
};

#define DECIMAL_POINT_MASK 0x80

/* Decode a pair of characters into a byte. */
static uint8_t decode_pair(const uint8_t *buf)
{
	unsigned int i;
	char hex[3];

	hex[2] = '\0';

	for (i = 0; i < 2; i++) {
		hex[i] = buf[i];
		if (hex[i] > 0x39)
			hex[i] += 7;
	}

	return strtol(hex, NULL, 16);
}

SR_PRIV gboolean sr_ut372_packet_valid(const uint8_t *buf)
{
	return (buf[25] == '\r' && buf[26] == '\n');
}

SR_PRIV int sr_ut372_parse(const uint8_t *buf, float *floatval,
		struct sr_datafeed_analog *analog, void *info)
{
	unsigned int i, j, value, divisor;
	uint8_t segments;

	(void) info;

	value = 0;
	divisor = 1;

	for (i = 0; i < 5; i++) {
		segments = decode_pair(buf + 1 + 2*i);
		for (j = 0; j < ARRAY_SIZE(lookup); j++) {
			if (lookup[j] == (segments & ~DECIMAL_POINT_MASK)) {
				value += j * pow(10, i);
				break;
			}
		}
		if (segments & DECIMAL_POINT_MASK)
			divisor = pow(10, i);
	}

	*floatval = (float) value / divisor;

	analog->mq = SR_MQ_FREQUENCY;
	analog->unit = SR_UNIT_REVOLUTIONS_PER_MINUTE;

	return SR_OK;
}
Commit	Line	Data
f3cde309 ML	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2015 Martin Ling <martin-sigrok@earth.li>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	/*
	22	* UNI-T UT372 protocol parser.
	23	*/
	24
472bef39	25	#include <stdlib.h>
118268a2	26	#include <stdint.h>
472bef39	27	#include <math.h>
f3cde309 ML	28	#include "libsigrok.h"
	29	#include "libsigrok-internal.h"
	30
	31	#define LOG_PREFIX "ut372"
	32
118268a2	33	uint8_t lookup[] = {
472bef39 ML	34	0x7B,
	35	0x60,
	36	0x5E,
	37	0x7C,
	38	0x65,
	39	0x3D,
	40	0x3F,
	41	0x70,
	42	0x7F,
	43	0x7D
	44	};
	45
	46	#define DECIMAL_POINT_MASK 0x80
	47
118268a2 ML	48	/* Decode a pair of characters into a byte. */
	49	static uint8_t decode_pair(const uint8_t *buf)
	50	{
	51	unsigned int i;
	52	char hex[3];
	53
	54	hex[2] = '\0';
	55
	56	for (i = 0; i < 2; i++) {
	57	hex[i] = buf[i];
	58	if (hex[i] > 0x39)
	59	hex[i] += 7;
	60	}
	61
	62	return strtol(hex, NULL, 16);
	63	}
	64
f3cde309 ML	65	SR_PRIV gboolean sr_ut372_packet_valid(const uint8_t *buf)
f3cde309 ML	66	{
472bef39	67	return (buf[25] == '\r' && buf[26] == '\n');
f3cde309 ML	68	}
	69
	70	SR_PRIV int sr_ut372_parse(const uint8_t buf, float floatval,
	71	struct sr_datafeed_analog analog, void info)
	72	{
118268a2 ML	73	unsigned int i, j, value, divisor;
118268a2 ML	74	uint8_t segments;
472bef39 ML	75
	76	(void) info;
	77
472bef39 ML	78	value = 0;
	79	divisor = 1;
	80
	81	for (i = 0; i < 5; i++) {
118268a2	82	segments = decode_pair(buf + 1 + 2*i);
472bef39 ML	83	for (j = 0; j < ARRAY_SIZE(lookup); j++) {
	84	if (lookup[j] == (segments & ~DECIMAL_POINT_MASK)) {
	85	value += j * pow(10, i);
	86	break;
	87	}
	88	}
	89	if (segments & DECIMAL_POINT_MASK)
	90	divisor = pow(10, i);
	91	}
	92
	93	*floatval = (float) value / divisor;
	94
	95	analog->mq = SR_MQ_FREQUENCY;
	96	analog->unit = SR_UNIT_REVOLUTIONS_PER_MINUTE;
	97
f3cde309 ML	98	return SR_OK;
f3cde309 ML	99	}