+++ /dev/null
-/*
- * This file is part of the libsigrok project.
- *
- * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
- *
- * 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/>.
- */
-
-/*
- * RadioShack 22-812 protocol parser.
- *
- * This protocol is currently encountered on the RadioShack 22-812 DMM.
- * It is a 9-byte packet representing a 1:1 mapping of the LCD segments, hence
- * the name rs9lcd.
- *
- * The chip is a bare die covered by a plastic blob. It is unclear if this chip
- * and protocol is used on any other device.
- */
-
-#include <string.h>
-#include <ctype.h>
-#include <math.h>
-#include <glib.h>
-#include "libsigrok.h"
-#include "libsigrok-internal.h"
-
-#define LOG_PREFIX "rs9lcd"
-
-/* Byte 1 of the packet, and the modes it represents */
-#define IND1_HZ (1 << 7)
-#define IND1_OHM (1 << 6)
-#define IND1_KILO (1 << 5)
-#define IND1_MEGA (1 << 4)
-#define IND1_FARAD (1 << 3)
-#define IND1_AMP (1 << 2)
-#define IND1_VOLT (1 << 1)
-#define IND1_MILI (1 << 0)
-/* Byte 2 of the packet, and the modes it represents */
-#define IND2_MICRO (1 << 7)
-#define IND2_NANO (1 << 6)
-#define IND2_DBM (1 << 5)
-#define IND2_SEC (1 << 4)
-#define IND2_DUTY (1 << 3)
-#define IND2_HFE (1 << 2)
-#define IND2_REL (1 << 1)
-#define IND2_MIN (1 << 0)
-/* Byte 7 of the packet, and the modes it represents */
-#define INFO_BEEP (1 << 7)
-#define INFO_DIODE (1 << 6)
-#define INFO_BAT (1 << 5)
-#define INFO_HOLD (1 << 4)
-#define INFO_NEG (1 << 3)
-#define INFO_AC (1 << 2)
-#define INFO_RS232 (1 << 1)
-#define INFO_AUTO (1 << 0)
-/* Instead of a decimal point, digit 4 carries the MAX flag */
-#define DIG4_MAX (1 << 3)
-/* Mask to remove the decimal point from a digit */
-#define DP_MASK (1 << 3)
-
-/* What the LCD values represent */
-#define LCD_0 0xd7
-#define LCD_1 0x50
-#define LCD_2 0xb5
-#define LCD_3 0xf1
-#define LCD_4 0x72
-#define LCD_5 0xe3
-#define LCD_6 0xe7
-#define LCD_7 0x51
-#define LCD_8 0xf7
-#define LCD_9 0xf3
-
-#define LCD_C 0x87
-#define LCD_E
-#define LCD_F
-#define LCD_h 0x66
-#define LCD_H 0x76
-#define LCD_I
-#define LCD_n
-#define LCD_P 0x37
-#define LCD_r
-
-enum {
- MODE_DC_V = 0,
- MODE_AC_V = 1,
- MODE_DC_UA = 2,
- MODE_DC_MA = 3,
- MODE_DC_A = 4,
- MODE_AC_UA = 5,
- MODE_AC_MA = 6,
- MODE_AC_A = 7,
- MODE_OHM = 8,
- MODE_FARAD = 9,
- MODE_HZ = 10,
- MODE_VOLT_HZ = 11, /* Dial set to V, Hz selected by Hz button */
- MODE_AMP_HZ = 12, /* Dial set to A, Hz selected by Hz button */
- MODE_DUTY = 13,
- MODE_VOLT_DUTY = 14, /* Dial set to V, duty cycle selected */
- MODE_AMP_DUTY = 15, /* Dial set to A, duty cycle selected */
- MODE_WIDTH = 16,
- MODE_VOLT_WIDTH = 17, /* Dial set to V, pulse width selected */
- MODE_AMP_WIDTH = 18, /* Dial set to A, pulse width selected */
- MODE_DIODE = 19,
- MODE_CONT = 20,
- MODE_HFE = 21,
- MODE_LOGIC = 22,
- MODE_DBM = 23,
- /* MODE_EF = 24, */ /* Not encountered on any DMM */
- MODE_TEMP = 25,
- MODE_INVALID = 26,
-};
-
-enum {
- READ_ALL,
- READ_TEMP,
-};
-
-struct rs9lcd_packet {
- uint8_t mode;
- uint8_t indicatrix1;
- uint8_t indicatrix2;
- uint8_t digit4;
- uint8_t digit3;
- uint8_t digit2;
- uint8_t digit1;
- uint8_t info;
- uint8_t checksum;
-};
-
-static gboolean checksum_valid(const struct rs9lcd_packet *rs_packet)
-{
- uint8_t *raw;
- uint8_t sum = 0;
- int i;
-
- raw = (void *)rs_packet;
-
- for (i = 0; i < RS9LCD_PACKET_SIZE - 1; i++)
- sum += raw[i];
-
- /* This is just a funky constant added to the checksum. */
- sum += 57;
- sum -= rs_packet->checksum;
- return (sum == 0);
-}
-
-static gboolean selection_good(const struct rs9lcd_packet *rs_packet)
-{
- int count;
-
- /* Does the packet have more than one multiplier? */
- count = 0;
- count += (rs_packet->indicatrix1 & IND1_KILO) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_MEGA) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_MILI) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_MICRO) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_NANO) ? 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 += (rs_packet->indicatrix1 & IND1_HZ) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_OHM) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_FARAD) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_AMP) ? 1 : 0;
- count += (rs_packet->indicatrix1 & IND1_VOLT) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_DBM) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_SEC) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_DUTY) ? 1 : 0;
- count += (rs_packet->indicatrix2 & IND2_HFE) ? 1 : 0;
- if (count > 1) {
- sr_dbg("More than one measurement type detected in packet.");
- return FALSE;
- }
-
- return TRUE;
-}
-
-/*
- * Since the 22-812 does not identify itself in any way, shape, or form,
- * we really don't know for sure who is sending the data. We must use every
- * possible check to filter out bad packets, especially since detection of the
- * 22-812 depends on how well we can filter the packets.
- */
-SR_PRIV gboolean sr_rs9lcd_packet_valid(const uint8_t *buf)
-{
- const struct rs9lcd_packet *rs_packet = (void *)buf;
-
- /*
- * Check for valid mode first, before calculating the checksum. No
- * point calculating the checksum, if we know we'll reject the packet.
- */
- if (!(rs_packet->mode < MODE_INVALID))
- return FALSE;
-
- if (!checksum_valid(rs_packet)) {
- sr_spew("Packet with invalid checksum. Discarding.");
- return FALSE;
- }
-
- if (!selection_good(rs_packet)) {
- sr_spew("Packet with invalid selection bits. Discarding.");
- return FALSE;
- }
-
- return TRUE;
-}
-
-static uint8_t decode_digit(uint8_t raw_digit)
-{
- /* Take out the decimal point, so we can use a simple switch(). */
- raw_digit &= ~DP_MASK;
-
- switch (raw_digit) {
- case 0x00:
- case LCD_0:
- return 0;
- case LCD_1:
- return 1;
- case LCD_2:
- return 2;
- case LCD_3:
- return 3;
- case LCD_4:
- return 4;
- case LCD_5:
- return 5;
- case LCD_6:
- return 6;
- case LCD_7:
- return 7;
- case LCD_8:
- return 8;
- case LCD_9:
- return 9;
- default:
- sr_dbg("Invalid digit byte: 0x%02x.", raw_digit);
- return 0xff;
- }
-}
-
-static double lcd_to_double(const struct rs9lcd_packet *rs_packet, int type)
-{
- double rawval = 0, multiplier = 1;
- uint8_t digit, raw_digit;
- gboolean dp_reached = FALSE;
- int i, end;
-
- /* end = 1: Don't parse last digit. end = 0: Parse all digits. */
- end = (type == READ_TEMP) ? 1 : 0;
-
- /* We have 4 digits, and we start from the most significant. */
- for (i = 3; i >= end; i--) {
- raw_digit = *(&(rs_packet->digit4) + i);
- digit = decode_digit(raw_digit);
- if (digit == 0xff) {
- rawval = NAN;
- break;
- }
- /*
- * Digit 1 does not have a decimal point. Instead, the decimal
- * point is used to indicate MAX, so we must avoid testing it.
- */
- if ((i < 3) && (raw_digit & DP_MASK))
- dp_reached = TRUE;
- if (dp_reached)
- multiplier /= 10;
- rawval = rawval * 10 + digit;
- }
- rawval *= multiplier;
- if (rs_packet->info & INFO_NEG)
- rawval *= -1;
-
- /* See if we need to multiply our raw value by anything. */
- if (rs_packet->indicatrix1 & IND2_NANO)
- rawval *= 1E-9;
- else if (rs_packet->indicatrix2 & IND2_MICRO)
- rawval *= 1E-6;
- else if (rs_packet->indicatrix1 & IND1_MILI)
- rawval *= 1E-3;
- else if (rs_packet->indicatrix1 & IND1_KILO)
- rawval *= 1E3;
- else if (rs_packet->indicatrix1 & IND1_MEGA)
- rawval *= 1E6;
-
- return rawval;
-}
-
-static gboolean is_celsius(const struct rs9lcd_packet *rs_packet)
-{
- return ((rs_packet->digit4 & ~DP_MASK) == LCD_C);
-}
-
-static gboolean is_shortcirc(const struct rs9lcd_packet *rs_packet)
-{
- return ((rs_packet->digit2 & ~DP_MASK) == LCD_h);
-}
-
-static gboolean is_logic_high(const struct rs9lcd_packet *rs_packet)
-{
- sr_spew("Digit 2: 0x%02x.", rs_packet->digit2 & ~DP_MASK);
- return ((rs_packet->digit2 & ~DP_MASK) == LCD_H);
-}
-
-SR_PRIV int sr_rs9lcd_parse(const uint8_t *buf, float *floatval,
- struct sr_datafeed_analog *analog, void *info)
-{
- const struct rs9lcd_packet *rs_packet = (void *)buf;
- double rawval;
-
- (void)info;
-
- rawval = lcd_to_double(rs_packet, READ_ALL);
-
- switch (rs_packet->mode) {
- case MODE_DC_V:
- analog->mq = SR_MQ_VOLTAGE;
- analog->unit = SR_UNIT_VOLT;
- analog->mqflags |= SR_MQFLAG_DC;
- break;
- case MODE_AC_V:
- analog->mq = SR_MQ_VOLTAGE;
- analog->unit = SR_UNIT_VOLT;
- analog->mqflags |= SR_MQFLAG_AC;
- break;
- case MODE_DC_UA: /* Fall through */
- case MODE_DC_MA: /* Fall through */
- case MODE_DC_A:
- analog->mq = SR_MQ_CURRENT;
- analog->unit = SR_UNIT_AMPERE;
- analog->mqflags |= SR_MQFLAG_DC;
- break;
- case MODE_AC_UA: /* Fall through */
- case MODE_AC_MA: /* Fall through */
- case MODE_AC_A:
- analog->mq = SR_MQ_CURRENT;
- analog->unit = SR_UNIT_AMPERE;
- analog->mqflags |= SR_MQFLAG_AC;
- break;
- case MODE_OHM:
- analog->mq = SR_MQ_RESISTANCE;
- analog->unit = SR_UNIT_OHM;
- break;
- case MODE_FARAD:
- analog->mq = SR_MQ_CAPACITANCE;
- analog->unit = SR_UNIT_FARAD;
- break;
- case MODE_CONT:
- analog->mq = SR_MQ_CONTINUITY;
- analog->unit = SR_UNIT_BOOLEAN;
- rawval = is_shortcirc(rs_packet);
- break;
- case MODE_DIODE:
- analog->mq = SR_MQ_VOLTAGE;
- analog->unit = SR_UNIT_VOLT;
- analog->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
- break;
- case MODE_HZ: /* Fall through */
- case MODE_VOLT_HZ: /* Fall through */
- case MODE_AMP_HZ:
- analog->mq = SR_MQ_FREQUENCY;
- analog->unit = SR_UNIT_HERTZ;
- break;
- case MODE_LOGIC:
- /*
- * No matter whether or not we have an actual voltage reading,
- * we are measuring voltage, so we set our MQ as VOLTAGE.
- */
- analog->mq = SR_MQ_VOLTAGE;
- if (!isnan(rawval)) {
- /* We have an actual voltage. */
- analog->unit = SR_UNIT_VOLT;
- } else {
- /* We have either HI or LOW. */
- analog->unit = SR_UNIT_BOOLEAN;
- rawval = is_logic_high(rs_packet);
- }
- break;
- case MODE_HFE:
- analog->mq = SR_MQ_GAIN;
- analog->unit = SR_UNIT_UNITLESS;
- break;
- case MODE_DUTY: /* Fall through */
- case MODE_VOLT_DUTY: /* Fall through */
- case MODE_AMP_DUTY:
- analog->mq = SR_MQ_DUTY_CYCLE;
- analog->unit = SR_UNIT_PERCENTAGE;
- break;
- case MODE_WIDTH: /* Fall through */
- case MODE_VOLT_WIDTH: /* Fall through */
- case MODE_AMP_WIDTH:
- analog->mq = SR_MQ_PULSE_WIDTH;
- analog->unit = SR_UNIT_SECOND;
- break;
- case MODE_TEMP:
- analog->mq = SR_MQ_TEMPERATURE;
- /* We need to reparse. */
- rawval = lcd_to_double(rs_packet, READ_TEMP);
- analog->unit = is_celsius(rs_packet) ?
- SR_UNIT_CELSIUS : SR_UNIT_FAHRENHEIT;
- break;
- case MODE_DBM:
- analog->mq = SR_MQ_POWER;
- analog->unit = SR_UNIT_DECIBEL_MW;
- analog->mqflags |= SR_MQFLAG_AC;
- break;
- default:
- sr_dbg("Unknown mode: %d.", rs_packet->mode);
- break;
- }
-
- if (rs_packet->info & INFO_HOLD)
- analog->mqflags |= SR_MQFLAG_HOLD;
- if (rs_packet->digit4 & DIG4_MAX)
- analog->mqflags |= SR_MQFLAG_MAX;
- if (rs_packet->indicatrix2 & IND2_MIN)
- analog->mqflags |= SR_MQFLAG_MIN;
- if (rs_packet->info & INFO_AUTO)
- analog->mqflags |= SR_MQFLAG_AUTORANGE;
-
- *floatval = rawval;
- return SR_OK;
-}
projects / libsigrok.git / blobdiff