hardware/radioshack-dmm/radioshack.c

   1 /*
   2  * This file is part of the sigrok project.
   3  *
   4  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   5  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <glib.h>
  22 #include "libsigrok.h"
  23 #include "libsigrok-internal.h"
  24 #include "config.h"
  25 #include "radioshack-dmm.h"
  26 #include <stdlib.h>
  27 #include <math.h>
  28 #include <string.h>
  29 #include <errno.h>
  30
  31
  32 static gboolean rs_22_812_is_checksum_valid(const rs_22_812_packet *data)
  33 {
  34         uint8_t *raw = (void *) data;
  35         uint8_t sum = 0;
  36         size_t i;
  37         for(i = 0; i < RS_22_812_PACKET_SIZE - 1; i++)
  38                 sum += raw[i];
  39         /* This is just a funky constant added to the checksum */
  40         sum += 57;
  41         sum -= data->checksum;
  42         return(sum == 0);
  43 }
  44
  45 static gboolean rs_22_812_is_mode_valid(rs_22_812_mode mode)
  46 {
  47         return(mode < RS_22_812_MODE_INVALID);
  48 }
  49
  50 static gboolean rs_22_812_is_selection_good(const rs_22_812_packet *data)
  51 {
  52         int n_postfix = 0;
  53         int n_type = 0;
  54         /* Does the packet have more than one multiplier ? */
  55         if(data->indicatrix1 & RS_22_812_IND1_KILO)
  56                 n_postfix++;
  57         if(data->indicatrix1 & RS_22_812_IND1_MEGA)
  58                 n_postfix++;
  59         if(data->indicatrix1 & RS_22_812_IND1_MILI)
  60                 n_postfix++;
  61         if(data->indicatrix2 & RS_22_812_IND2_MICRO)
  62                 n_postfix++;
  63         if(data->indicatrix2 & RS_22_812_IND2_NANO)
  64                 n_postfix++;
  65         if(n_postfix > 1)
  66                 return FALSE;
  67
  68         /* Does the packet "measure" more than one type of value ?*/
  69         if(data->indicatrix1 & RS_22_812_IND1_HZ)
  70                 n_type++;
  71         if(data->indicatrix1 & RS_22_812_IND1_OHM)
  72                 n_type++;
  73         if(data->indicatrix1 & RS_22_812_IND1_FARAD)
  74                 n_type++;
  75         if(data->indicatrix1 & RS_22_812_IND1_AMP)
  76                 n_type++;
  77         if(data->indicatrix1 & RS_22_812_IND1_VOLT)
  78                 n_type++;
  79         if(data->indicatrix2 & RS_22_812_IND2_DBM)
  80                 n_type++;
  81         if(data->indicatrix2 & RS_22_812_IND2_SEC)
  82                 n_type++;
  83         if(data->indicatrix2 & RS_22_812_IND2_DUTY)
  84                 n_type++;
  85         if(data->indicatrix2 & RS_22_812_IND2_HFE)
  86                 n_type++;
  87         if(n_type > 1)
  88                 return FALSE;
  89
  90         /* OK, no duplicates */
  91         return TRUE;
  92 }
  93
  94 /* Since the RS 22-812 does not identify itslef in any way shape, or form,
  95  * we really don't know for sure who is sending the data. We must use every
  96  * possible check to filter out bad packets, especially since detection of the
  97  * 22-812 depends on how well we can filter the packets */
  98 SR_PRIV gboolean rs_22_812_is_packet_valid(const rs_22_812_packet *packet)
  99 {
 100         /* Unfortunately, the packet doesn't have a signature, so we must
 101          * compute its checksum first */
 102         if(!rs_22_812_is_checksum_valid(packet))
 103                 return FALSE;
 104
 105         if(!rs_22_812_is_mode_valid(packet->mode))
 106                 return FALSE;
 107
 108         if(!rs_22_812_is_selection_good(packet)) {
 109                 return FALSE;
 110         }
 111         /* Made it here, huh? Then this looks to be a valid packet */
 112         return TRUE;
 113 }
 114
 115 static uint8_t rs_22_812_to_digit(uint8_t raw_digit)
 116 {
 117         /* Take out the decimal point, so we can use a simple switch() */
 118         raw_digit &= ~RS_22_812_DP_MASK;
 119         switch(raw_digit)
 120         {
 121         case 0x00:
 122         case RS_22_812_LCD_0:
 123                 return 0;
 124         case RS_22_812_LCD_1:
 125                 return 1;
 126         case RS_22_812_LCD_2:
 127                 return 2;
 128         case RS_22_812_LCD_3:
 129                 return 3;
 130         case RS_22_812_LCD_4:
 131                 return 4;
 132         case RS_22_812_LCD_5:
 133                 return 5;
 134         case RS_22_812_LCD_6:
 135                 return 6;
 136         case RS_22_812_LCD_7:
 137                 return 7;
 138         case RS_22_812_LCD_8:
 139                 return 8;
 140         case RS_22_812_LCD_9:
 141                 return 9;
 142         default:
 143                 return 0xff;
 144         }
 145 }
 146
 147 typedef enum {
 148         READ_ALL,
 149         READ_TEMP,
 150 } value_type;
 151
 152 static double lcdraw_to_double(rs_22_812_packet *rs_packet, value_type type)
 153 {
 154         /* *********************************************************************
 155          * Get a raw floating point value from the data
 156          **********************************************************************/
 157         double rawval;
 158         double multiplier = 1;
 159         uint8_t digit;
 160         gboolean dp_reached = FALSE;
 161         int i, end;
 162         switch(type) {
 163         case READ_TEMP:
 164                 /* Do not parse the last digit */
 165                 end = 1;
 166                 break;
 167         case READ_ALL:
 168         default:
 169                 /* Parse all digits */
 170                 end = 0;
 171         }
 172         /* We have 4 digits, and we start from the most significant */
 173         for(i = 3; i >= end; i--)
 174         {
 175                 uint8_t raw_digit = *(&(rs_packet->digit4) + i);
 176                 digit = rs_22_812_to_digit(raw_digit);
 177                 if(digit == 0xff) {
 178                         rawval = NAN;
 179                         break;
 180                 }
 181                 /* Digit 1 does not have a decimal point. Instead, the decimal
 182                  * point is used to indicate MAX, so we must avoid testing it */
 183                 if( (i < 3) && (raw_digit & RS_22_812_DP_MASK) )
 184                         dp_reached = TRUE;
 185                 if(dp_reached) multiplier /= 10;
 186                 rawval = rawval * 10 + digit;
 187         }
 188         rawval *= multiplier;
 189         if(rs_packet->info & RS_22_812_INFO_NEG)
 190                 rawval *= -1;
 191
 192         /* See if we need to multiply our raw value by anything */
 193         if(rs_packet->indicatrix1 & RS_22_812_IND2_NANO) {
 194                 rawval *= 1E-9;
 195         } else if(rs_packet->indicatrix2 & RS_22_812_IND2_MICRO) {
 196                 rawval *= 1E-6;
 197         } else if(rs_packet->indicatrix1 & RS_22_812_IND1_MILI) {
 198                 rawval *= 1E-3;
 199         } else if(rs_packet->indicatrix1 & RS_22_812_IND1_KILO) {
 200                 rawval *= 1E3;
 201         } else if(rs_packet->indicatrix1 & RS_22_812_IND1_MEGA) {
 202                 rawval *= 1E6;
 203         }
 204
 205         return rawval;
 206 }
 207
 208 static gboolean rs_22_812_is_celsius(rs_22_812_packet *rs_packet)
 209 {
 210         return((rs_packet->digit4 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_C);
 211 }
 212
 213 static gboolean rs_22_812_is_shortcirc(rs_22_812_packet *rs_packet)
 214 {
 215         return((rs_packet->digit2 & ~RS_22_812_DP_MASK) == RS_22_812_LCD_h);
 216 }
 217
 218 static void rs_22_812_handle_packet(rs_22_812_packet *rs_packet,
 219                                     rs_dev_ctx *devc)
 220 {
 221         double rawval = lcdraw_to_double(rs_packet, READ_ALL);
 222         /* *********************************************************************
 223          * Now see what the value means, and pass that on
 224          **********************************************************************/
 225         struct sr_datafeed_packet packet;
 226         struct sr_datafeed_analog *analog;
 227
 228         analog = g_try_malloc0(sizeof(struct sr_datafeed_analog));
 229         analog->num_samples = 1;
 230         analog->data = g_try_malloc(sizeof(float));
 231         *analog->data = (float)rawval;
 232         analog->mq = -1;
 233
 234         switch(rs_packet->mode) {
 235         case RS_22_812_MODE_DC_V:
 236                 analog->mq = SR_MQ_VOLTAGE;
 237                 analog->unit = SR_UNIT_VOLT;
 238                 analog->mqflags |= SR_MQFLAG_DC;
 239                 break;
 240         case RS_22_812_MODE_AC_V:
 241                 analog->mq = SR_MQ_VOLTAGE;
 242                 analog->unit = SR_UNIT_VOLT;
 243                 analog->mqflags |= SR_MQFLAG_AC;
 244                 break;
 245         case RS_22_812_MODE_DC_UA:
 246         case RS_22_812_MODE_DC_MA:
 247         case RS_22_812_MODE_DC_A:
 248                 analog->mq = SR_MQ_CURRENT;
 249                 analog->unit = SR_UNIT_AMPERE;
 250                 analog->mqflags |= SR_MQFLAG_DC;
 251                 break;
 252         case RS_22_812_MODE_AC_UA:
 253         case RS_22_812_MODE_AC_MA:
 254         case RS_22_812_MODE_AC_A:
 255                 analog->mq = SR_MQ_CURRENT;
 256                 analog->unit = SR_UNIT_AMPERE;
 257                 analog->mqflags |= SR_MQFLAG_AC;
 258                 break;
 259         case RS_22_812_MODE_OHM:
 260                 analog->mq = SR_MQ_RESISTANCE;
 261                 analog->unit = SR_UNIT_OHM;
 262                 break;
 263         case RS_22_812_MODE_FARAD:
 264                 analog->mq = SR_MQ_CAPACITANCE;
 265                 analog->unit = SR_UNIT_FARAD;
 266                 break;
 267         case RS_22_812_MODE_CONT:
 268                 analog->mq = SR_MQ_CONTINUITY;
 269                 analog->unit = SR_UNIT_BOOLEAN;
 270                 *analog->data = rs_22_812_is_shortcirc(rs_packet);
 271                 break;
 272         case RS_22_812_MODE_DIODE:
 273                 analog->mq = SR_MQ_VOLTAGE;
 274                 analog->unit = SR_UNIT_VOLT;
 275                 analog->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
 276                 break;
 277         case RS_22_812_MODE_HZ:
 278         case RS_22_812_MODE_VOLT_HZ:
 279         case RS_22_812_MODE_AMP_HZ:
 280                 analog->mq = SR_MQ_FREQUENCY;
 281                 analog->unit = SR_UNIT_HERTZ;
 282                 break;
 283         case RS_22_812_MODE_LOGIC:
 284                 analog->mq = 0; /* FIXME */
 285                 analog->unit = SR_UNIT_BOOLEAN;
 286                 sr_warn("radioshack-dmm: LOGIC mode not supported yet");
 287                 g_free(analog->data);
 288                 g_free(analog);
 289                 return;
 290                 break;
 291         case RS_22_812_MODE_HFE:
 292                 analog->mq = SR_MQ_GAIN;
 293                 analog->unit = SR_UNIT_UNITLESS;
 294                 break;
 295         case RS_22_812_MODE_DUTY:
 296         case RS_22_812_MODE_VOLT_DUTY:
 297         case RS_22_812_MODE_AMP_DUTY:
 298                 analog->mq = SR_MQ_DUTY_CYCLE;
 299                 analog->unit = SR_UNIT_PERCENTAGE;
 300                 break;
 301         case RS_22_812_MODE_WIDTH:
 302         case RS_22_812_MODE_VOLT_WIDTH:
 303         case RS_22_812_MODE_AMP_WIDTH:
 304                 analog->mq = SR_MQ_PULSE_WIDTH;
 305                 analog->unit = SR_UNIT_SECOND;
 306         case RS_22_812_MODE_TEMP:
 307                 analog->mq = SR_MQ_TEMPERATURE;
 308                 /* We need to reparse */
 309                 *analog->data = lcdraw_to_double(rs_packet, READ_TEMP);
 310                 analog->unit = rs_22_812_is_celsius(rs_packet)?
 311                                 SR_UNIT_CELSIUS:SR_UNIT_FAHRENHEIT;
 312                 break;
 313         case RS_22_812_MODE_DBM:
 314                 analog->mq = SR_MQ_POWER;
 315                 analog->unit = SR_UNIT_DECIBEL_MW;
 316                 analog->mqflags |= SR_MQFLAG_AC;
 317                 break;
 318         default:
 319                 sr_warn("radioshack-dmm: unkown mode: %d", rs_packet->mode);
 320                 break;
 321         }
 322
 323         if(rs_packet->info & RS_22_812_INFO_HOLD) {
 324                 analog->mqflags |= SR_MQFLAG_HOLD;
 325         }
 326         if(rs_packet->digit4 & RS_22_812_DIG4_MAX) {
 327                 analog->mqflags |= SR_MQFLAG_MAX;
 328         }
 329         if(rs_packet->indicatrix2 & RS_22_812_IND2_MIN) {
 330                 analog->mqflags |= SR_MQFLAG_MIN;
 331         }
 332         if(rs_packet->info & RS_22_812_INFO_AUTO) {
 333                 analog->mqflags |= SR_MQFLAG_AUTORANGE;
 334         }
 335
 336         if (analog->mq != -1) {
 337                 /* Got a measurement. */
 338                 sr_spew("radioshack-dmm: val %f", rawval);
 339                 packet.type = SR_DF_ANALOG;
 340                 packet.payload = analog;
 341                 sr_session_send(devc->cb_data, &packet);
 342                 devc->num_samples++;
 343         }
 344         g_free(analog->data);
 345         g_free(analog);
 346 }
 347
 348 static void handle_new_data(rs_dev_ctx *devc, int fd)
 349 {
 350         int len;
 351         size_t i;
 352         size_t offset = 0;
 353         /* Try to get as much data as the buffer can hold */
 354         len = RS_DMM_BUFSIZE - devc->buflen;
 355         len = serial_read(fd, devc->buf + devc->buflen, len);
 356         if (len < 1) {
 357                 sr_err("radioshack-dmm: serial port read error!");
 358                 return;
 359         }
 360         devc->buflen += len;
 361
 362         /* Now look for packets in that data */
 363         while((devc->buflen - offset) >= RS_22_812_PACKET_SIZE)
 364         {
 365                 rs_22_812_packet * packet = (void *)(devc->buf + offset);
 366                 if( rs_22_812_is_packet_valid(packet) )
 367                 {
 368                         rs_22_812_handle_packet(packet, devc);
 369                         offset += RS_22_812_PACKET_SIZE;
 370                 } else {
 371                         offset++;
 372                 }
 373         }
 374
 375         /* If we have any data left, move it to the beginning of our buffer */
 376         for(i = 0; i < devc->buflen - offset; i++)
 377                 devc->buf[i] = devc->buf[offset + i];
 378         devc->buflen -= offset;
 379 }
 380
 381 SR_PRIV int radioshack_receive_data(int fd, int revents, void *cb_data)
 382 {
 383         const struct sr_dev_inst *sdi;
 384         struct dev_context *devc;
 385
 386         if (!(sdi = cb_data))
 387                 return TRUE;
 388
 389         if (!(devc = sdi->priv))
 390                 return TRUE;
 391
 392         if (revents == G_IO_IN)
 393         {
 394                 /* Serial data arrived. */
 395                 handle_new_data(devc, fd);
 396         }
 397
 398         if (devc->num_samples >= devc->limit_samples) {
 399                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 400                 return TRUE;
 401         }
 402
 403         return TRUE;
 404 }
 405
 406