]> sigrok.org Git - libsigrok.git/blame - src/dmm/ut372.c
Add SR_MQ_COUNT for event count measurements.
[libsigrok.git] / src / dmm / ut372.c
CommitLineData
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 33uint8_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
8c9092b0
ML
48#define FLAGS1_HOLD_MASK (1 << 2)
49
50#define FLAGS2_RPM_MASK (1 << 0)
51#define FLAGS2_MAX_MASK (1 << 4)
52#define FLAGS2_MIN_MASK (1 << 5)
53#define FLAGS2_AVE_MASK (1 << 6)
54
118268a2
ML
55/* Decode a pair of characters into a byte. */
56static uint8_t decode_pair(const uint8_t *buf)
57{
58 unsigned int i;
59 char hex[3];
60
61 hex[2] = '\0';
62
63 for (i = 0; i < 2; i++) {
64 hex[i] = buf[i];
65 if (hex[i] > 0x39)
66 hex[i] += 7;
67 }
68
69 return strtol(hex, NULL, 16);
70}
71
f3cde309
ML
72SR_PRIV gboolean sr_ut372_packet_valid(const uint8_t *buf)
73{
472bef39 74 return (buf[25] == '\r' && buf[26] == '\n');
f3cde309
ML
75}
76
77SR_PRIV int sr_ut372_parse(const uint8_t *buf, float *floatval,
78 struct sr_datafeed_analog *analog, void *info)
79{
118268a2 80 unsigned int i, j, value, divisor;
8c9092b0 81 uint8_t segments, flags1, flags2;
472bef39
ML
82
83 (void) info;
84
8c9092b0
ML
85 flags1 = decode_pair(buf + 21);
86 flags2 = decode_pair(buf + 23);
87
88 /* If not in RPM mode, ignore packet. */
89 if (!(flags2 & FLAGS2_RPM_MASK)) {
90 sr_dbg("Not in RPM mode. Count mode is unsupported.");
91 return SR_ERR_NA;
92 }
93
94 if (flags1 & FLAGS1_HOLD_MASK)
95 analog->mqflags |= SR_MQFLAG_HOLD;
96 if (flags2 & FLAGS2_MIN_MASK)
97 analog->mqflags |= SR_MQFLAG_MIN;
98 if (flags2 & FLAGS2_MAX_MASK)
99 analog->mqflags |= SR_MQFLAG_MAX;
100 if (flags2 & FLAGS2_AVE_MASK)
101 analog->mqflags |= SR_MQFLAG_AVG;
102
472bef39
ML
103 value = 0;
104 divisor = 1;
105
106 for (i = 0; i < 5; i++) {
118268a2 107 segments = decode_pair(buf + 1 + 2*i);
472bef39
ML
108 for (j = 0; j < ARRAY_SIZE(lookup); j++) {
109 if (lookup[j] == (segments & ~DECIMAL_POINT_MASK)) {
110 value += j * pow(10, i);
111 break;
112 }
113 }
114 if (segments & DECIMAL_POINT_MASK)
115 divisor = pow(10, i);
116 }
117
118 *floatval = (float) value / divisor;
119
120 analog->mq = SR_MQ_FREQUENCY;
121 analog->unit = SR_UNIT_REVOLUTIONS_PER_MINUTE;
122
f3cde309
ML
123 return SR_OK;
124}