libsigrok/hardware/radioshack-dmm/radioshack.c

394 lines
10 KiB
C

/*
* This file is part of the sigrok project.
*
* Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
* 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/>.
*/
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <errno.h>
#include <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include "radioshack-dmm.h"
enum {
READ_ALL,
READ_TEMP,
};
static gboolean checksum_valid(const struct rs_22_812_packet *rs_packet)
{
uint8_t *raw;
uint8_t sum = 0;
int i;
raw = (void *)rs_packet;
for (i = 0; i < RS_22_812_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 rs_22_812_packet *rs_packet)
{
int count;
/* Does the packet have more than one multiplier ? */
count = 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_KILO) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_MEGA) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_MILI) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_MICRO) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_NANO) ? 1 : 0;
if (count > 1) {
sr_err("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 & RS_22_812_IND1_HZ) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_OHM) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_FARAD) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_AMP) ? 1 : 0;
count += (rs_packet->indicatrix1 & RS_22_812_IND1_VOLT) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_DBM) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_SEC) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_DUTY) ? 1 : 0;
count += (rs_packet->indicatrix2 & RS_22_812_IND2_HFE) ? 1 : 0;
if (count > 1) {
sr_err("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 rs_22_812_packet_valid(const struct rs_22_812_packet *rs_packet)
{
if (!checksum_valid(rs_packet))
return FALSE;
if (!(rs_packet->mode < RS_22_812_MODE_INVALID))
return FALSE;
if (!selection_good(rs_packet))
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 &= ~RS_22_812_DP_MASK;
switch (raw_digit) {
case 0x00:
case RS_22_812_LCD_0:
return 0;
case RS_22_812_LCD_1:
return 1;
case RS_22_812_LCD_2:
return 2;
case RS_22_812_LCD_3:
return 3;
case RS_22_812_LCD_4:
return 4;
case RS_22_812_LCD_5:
return 5;
case RS_22_812_LCD_6:
return 6;
case RS_22_812_LCD_7:
return 7;
case RS_22_812_LCD_8:
return 8;
case RS_22_812_LCD_9:
return 9;
default:
sr_err("Invalid digit byte: 0x%02x.", raw_digit);
return 0xff;
}
}
static double lcdraw_to_double(const struct rs_22_812_packet *rs_packet,
int type)
{
double rawval, 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 & RS_22_812_DP_MASK))
dp_reached = TRUE;
if (dp_reached)
multiplier /= 10;
rawval = rawval * 10 + digit;
}
rawval *= multiplier;
if (rs_packet->info & RS_22_812_INFO_NEG)
rawval *= -1;
/* See if we need to multiply our raw value by anything. */
if (rs_packet->indicatrix1 & RS_22_812_IND2_NANO) {
rawval *= 1E-9;
} else if (rs_packet->indicatrix2 & RS_22_812_IND2_MICRO) {
rawval *= 1E-6;
} else if (rs_packet->indicatrix1 & RS_22_812_IND1_MILI) {
rawval *= 1E-3;
} else if (rs_packet->indicatrix1 & RS_22_812_IND1_KILO) {
rawval *= 1E3;
} else if (rs_packet->indicatrix1 & RS_22_812_IND1_MEGA) {
rawval *= 1E6;
}
return rawval;
}
static gboolean is_celsius(struct rs_22_812_packet *rs_packet)
{
return ((rs_packet->digit4 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_C);
}
static gboolean is_shortcirc(struct rs_22_812_packet *rs_packet)
{
return ((rs_packet->digit2 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_h);
}
static gboolean is_logic_high(struct rs_22_812_packet *rs_packet)
{
sr_spew("Digit 2: 0x%02x.", rs_packet->digit2 & ~RS_22_812_DP_MASK);
return ((rs_packet->digit2 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_H);
}
static void handle_packet(struct rs_22_812_packet *rs_packet,
struct dev_context *devc)
{
double rawval;
struct sr_datafeed_packet packet;
struct sr_datafeed_analog *analog;
rawval = lcdraw_to_double(rs_packet, READ_ALL);
/* TODO: Check malloc return value. */
analog = g_try_malloc0(sizeof(struct sr_datafeed_analog));
analog->num_samples = 1;
/* TODO: Check malloc return value. */
analog->data = g_try_malloc(sizeof(float));
*analog->data = (float)rawval;
analog->mq = -1;
switch (rs_packet->mode) {
case RS_22_812_MODE_DC_V:
analog->mq = SR_MQ_VOLTAGE;
analog->unit = SR_UNIT_VOLT;
analog->mqflags |= SR_MQFLAG_DC;
break;
case RS_22_812_MODE_AC_V:
analog->mq = SR_MQ_VOLTAGE;
analog->unit = SR_UNIT_VOLT;
analog->mqflags |= SR_MQFLAG_AC;
break;
case RS_22_812_MODE_DC_UA:
case RS_22_812_MODE_DC_MA:
case RS_22_812_MODE_DC_A:
analog->mq = SR_MQ_CURRENT;
analog->unit = SR_UNIT_AMPERE;
analog->mqflags |= SR_MQFLAG_DC;
break;
case RS_22_812_MODE_AC_UA:
case RS_22_812_MODE_AC_MA:
case RS_22_812_MODE_AC_A:
analog->mq = SR_MQ_CURRENT;
analog->unit = SR_UNIT_AMPERE;
analog->mqflags |= SR_MQFLAG_AC;
break;
case RS_22_812_MODE_OHM:
analog->mq = SR_MQ_RESISTANCE;
analog->unit = SR_UNIT_OHM;
break;
case RS_22_812_MODE_FARAD:
analog->mq = SR_MQ_CAPACITANCE;
analog->unit = SR_UNIT_FARAD;
break;
case RS_22_812_MODE_CONT:
analog->mq = SR_MQ_CONTINUITY;
analog->unit = SR_UNIT_BOOLEAN;
*analog->data = is_shortcirc(rs_packet);
break;
case RS_22_812_MODE_DIODE:
analog->mq = SR_MQ_VOLTAGE;
analog->unit = SR_UNIT_VOLT;
analog->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
break;
case RS_22_812_MODE_HZ:
case RS_22_812_MODE_VOLT_HZ:
case RS_22_812_MODE_AMP_HZ:
analog->mq = SR_MQ_FREQUENCY;
analog->unit = SR_UNIT_HERTZ;
break;
case RS_22_812_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;
*analog->data = is_logic_high(rs_packet);
}
break;
case RS_22_812_MODE_HFE:
analog->mq = SR_MQ_GAIN;
analog->unit = SR_UNIT_UNITLESS;
break;
case RS_22_812_MODE_DUTY:
case RS_22_812_MODE_VOLT_DUTY:
case RS_22_812_MODE_AMP_DUTY:
analog->mq = SR_MQ_DUTY_CYCLE;
analog->unit = SR_UNIT_PERCENTAGE;
break;
case RS_22_812_MODE_WIDTH:
case RS_22_812_MODE_VOLT_WIDTH:
case RS_22_812_MODE_AMP_WIDTH:
analog->mq = SR_MQ_PULSE_WIDTH;
analog->unit = SR_UNIT_SECOND;
case RS_22_812_MODE_TEMP:
analog->mq = SR_MQ_TEMPERATURE;
/* We need to reparse. */
*analog->data = lcdraw_to_double(rs_packet, READ_TEMP);
analog->unit = is_celsius(rs_packet) ?
SR_UNIT_CELSIUS : SR_UNIT_FAHRENHEIT;
break;
case RS_22_812_MODE_DBM:
analog->mq = SR_MQ_POWER;
analog->unit = SR_UNIT_DECIBEL_MW;
analog->mqflags |= SR_MQFLAG_AC;
break;
default:
sr_err("Unknown mode: %d.", rs_packet->mode);
break;
}
if (rs_packet->info & RS_22_812_INFO_HOLD)
analog->mqflags |= SR_MQFLAG_HOLD;
if (rs_packet->digit4 & RS_22_812_DIG4_MAX)
analog->mqflags |= SR_MQFLAG_MAX;
if (rs_packet->indicatrix2 & RS_22_812_IND2_MIN)
analog->mqflags |= SR_MQFLAG_MIN;
if (rs_packet->info & RS_22_812_INFO_AUTO)
analog->mqflags |= SR_MQFLAG_AUTORANGE;
if (analog->mq != -1) {
/* Got a measurement. */
sr_spew("Value: %f.", rawval);
packet.type = SR_DF_ANALOG;
packet.payload = analog;
sr_session_send(devc->cb_data, &packet);
devc->num_samples++;
}
g_free(analog->data);
g_free(analog);
}
static void handle_new_data(struct dev_context *devc, int fd)
{
int len;
size_t i, offset = 0;
struct rs_22_812_packet *rs_packet;
/* Try to get as much data as the buffer can hold. */
len = RS_DMM_BUFSIZE - devc->buflen;
len = serial_read(fd, devc->buf + devc->buflen, len);
if (len < 1) {
sr_err("Serial port read error.");
return;
}
devc->buflen += len;
/* Now look for packets in that data. */
while ((devc->buflen - offset) >= RS_22_812_PACKET_SIZE) {
rs_packet = (void *)(devc->buf + offset);
if (rs_22_812_packet_valid(rs_packet)) {
handle_packet(rs_packet, devc);
offset += RS_22_812_PACKET_SIZE;
} else {
offset++;
}
}
/* If we have any data left, move it to the beginning of our buffer. */
for (i = 0; i < devc->buflen - offset; i++)
devc->buf[i] = devc->buf[offset + i];
devc->buflen -= offset;
}
SR_PRIV int radioshack_dmm_receive_data(int fd, int revents, void *cb_data)
{
struct sr_dev_inst *sdi;
struct dev_context *devc;
if (!(sdi = cb_data))
return TRUE;
if (!(devc = sdi->priv))
return TRUE;
if (revents == G_IO_IN) {
/* Serial data arrived. */
handle_new_data(devc, fd);
}
if (devc->num_samples >= devc->limit_samples) {
sdi->driver->dev_acquisition_stop(sdi, cb_data);
return TRUE;
}
return TRUE;
}