libsigrok/hardware/radioshack-dmm/radioshack.c

417 lines
11 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 <glib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include "config.h"
#include "radioshack-dmm.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <errno.h>
static gboolean rs_22_812_is_checksum_valid(const rs_22_812_packet *data)
{
uint8_t *raw = (void *) data;
uint8_t sum = 0;
size_t i;
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 -= data->checksum;
return(sum == 0);
}
static gboolean rs_22_812_is_mode_valid(rs_22_812_mode mode)
{
return(mode < RS_22_812_MODE_INVALID);
}
static gboolean rs_22_812_is_selection_good(const rs_22_812_packet *data)
{
int n_postfix = 0;
int n_type = 0;
/* Does the packet have more than one multiplier ? */
if(data->indicatrix1 & RS_22_812_IND1_KILO)
n_postfix++;
if(data->indicatrix1 & RS_22_812_IND1_MEGA)
n_postfix++;
if(data->indicatrix1 & RS_22_812_IND1_MILI)
n_postfix++;
if(data->indicatrix2 & RS_22_812_IND2_MICRO)
n_postfix++;
if(data->indicatrix2 & RS_22_812_IND2_NANO)
n_postfix++;
if(n_postfix > 1)
return FALSE;
/* Does the packet "measure" more than one type of value ?*/
if(data->indicatrix1 & RS_22_812_IND1_HZ)
n_type++;
if(data->indicatrix1 & RS_22_812_IND1_OHM)
n_type++;
if(data->indicatrix1 & RS_22_812_IND1_FARAD)
n_type++;
if(data->indicatrix1 & RS_22_812_IND1_AMP)
n_type++;
if(data->indicatrix1 & RS_22_812_IND1_VOLT)
n_type++;
if(data->indicatrix2 & RS_22_812_IND2_DBM)
n_type++;
if(data->indicatrix2 & RS_22_812_IND2_SEC)
n_type++;
if(data->indicatrix2 & RS_22_812_IND2_DUTY)
n_type++;
if(data->indicatrix2 & RS_22_812_IND2_HFE)
n_type++;
if(n_type > 1)
return FALSE;
/* OK, no duplicates */
return TRUE;
}
/* Since the RS 22-812 does not identify itslef 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_is_packet_valid(const rs_22_812_packet *packet)
{
/* Unfortunately, the packet doesn't have a signature, so we must
* compute its checksum first */
if(!rs_22_812_is_checksum_valid(packet))
return FALSE;
if(!rs_22_812_is_mode_valid(packet->mode))
return FALSE;
if(!rs_22_812_is_selection_good(packet)) {
return FALSE;
}
/* Made it here, huh? Then this looks to be a valid packet */
return TRUE;
}
static uint8_t rs_22_812_to_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:
return 0xff;
}
}
typedef enum {
READ_ALL,
READ_TEMP,
} value_type;
static double lcdraw_to_double(rs_22_812_packet *rs_packet, value_type type)
{
/* *********************************************************************
* Get a raw floating point value from the data
**********************************************************************/
double rawval;
double multiplier = 1;
uint8_t digit;
gboolean dp_reached = FALSE;
int i, end;
switch(type) {
case READ_TEMP:
/* Do not parse the last digit */
end = 1;
break;
case READ_ALL:
default:
/* Parse all digits */
end = 0;
}
/* We have 4 digits, and we start from the most significant */
for(i = 3; i >= end; i--)
{
uint8_t raw_digit = *(&(rs_packet->digit4) + i);
digit = rs_22_812_to_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 rs_22_812_is_celsius(rs_22_812_packet *rs_packet)
{
return((rs_packet->digit4 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_C);
}
static gboolean rs_22_812_is_shortcirc(rs_22_812_packet *rs_packet)
{
return((rs_packet->digit2 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_h);
}
static gboolean rs_22_812_is_logic_high(rs_22_812_packet *rs_packet)
{
sr_spew("digit 2: %x", rs_packet->digit2 & ~RS_22_812_DP_MASK);
return((rs_packet->digit2 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_H);
}
static void rs_22_812_handle_packet(rs_22_812_packet *rs_packet,
rs_dev_ctx *devc)
{
double rawval = lcdraw_to_double(rs_packet, READ_ALL);
/* *********************************************************************
* Now see what the value means, and pass that on
**********************************************************************/
struct sr_datafeed_packet packet;
struct sr_datafeed_analog *analog;
analog = g_try_malloc0(sizeof(struct sr_datafeed_analog));
analog->num_samples = 1;
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 = rs_22_812_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 = rs_22_812_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 = rs_22_812_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_warn("radioshack-dmm: unkown 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("radioshack-dmm: val %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(rs_dev_ctx *devc, int fd)
{
int len;
size_t i;
size_t offset = 0;
/* 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("radioshack-dmm: 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_22_812_packet * packet = (void *)(devc->buf + offset);
if( rs_22_812_is_packet_valid(packet) )
{
rs_22_812_handle_packet(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_receive_data(int fd, int revents, void *cb_data)
{
const 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;
}