hardware/colead-slm/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   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 3 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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <glib.h>
  22 #include "libsigrok.h"
  23 #include "libsigrok-internal.h"
  24 #include "protocol.h"
  25 #include <errno.h>
  26 #include <string.h>
  27
  28
  29 static void process_packet(const struct sr_dev_inst *sdi)
  30 {
  31         struct dev_context *devc;
  32         struct sr_datafeed_packet packet;
  33         struct sr_datafeed_analog analog;
  34         GString *dbg;
  35         float fvalue;
  36         int checksum, mode, i;
  37
  38         devc = sdi->priv;
  39         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
  40                 dbg = g_string_sized_new(128);
  41                 g_string_printf(dbg, "received packet:");
  42                 for (i = 0; i < 10; i++)
  43                         g_string_append_printf(dbg, " %.2x", (devc->buf)[i]);
  44                 sr_spew("%s", dbg->str);
  45                 g_string_free(dbg, TRUE);
  46         }
  47
  48         if (devc->buf[0] != 0x08 || devc->buf[1] != 0x04) {
  49                 sr_dbg("invalid packet header.");
  50                 return;
  51         }
  52
  53         if (devc->buf[8] != 0x01) {
  54                 sr_dbg("invalid measurement.");
  55                 return;
  56         }
  57
  58         checksum = 0;
  59         for (i = 0; i < 9; i++)
  60                 checksum += devc->buf[i];
  61         if ((checksum & 0xff) != devc->buf[9]) {
  62                 sr_dbg("invalid packet checksum.");
  63                 return;
  64         }
  65
  66         fvalue = 0.0;
  67         for (i = 3; i < 8; i++) {
  68                 if (devc->buf[i] > 0x09)
  69                         continue;
  70                 fvalue *= 10;
  71                 fvalue += devc->buf[i];
  72         }
  73         fvalue /= 10;
  74
  75         memset(&analog, 0, sizeof(struct sr_datafeed_analog));
  76         analog.mq = SR_MQ_SOUND_PRESSURE_LEVEL;
  77         analog.unit = SR_UNIT_DECIBEL_SPL;
  78         analog.probes = sdi->probes;
  79         analog.num_samples = 1;
  80         analog.data = &fvalue;
  81
  82         /* High nibble should only have 0x01 or 0x02. */
  83         mode = (devc->buf[2] >> 4) & 0x0f;
  84         if (mode == 0x02)
  85                 analog.mqflags |= SR_MQFLAG_HOLD;
  86         else if (mode != 0x01) {
  87                 sr_dbg("unknown measurement mode 0x%.2x", mode);
  88                 return;
  89         }
  90
  91         /* Low nibble has 14 combinations of direct/long-term average,
  92          * time scale of that average, frequency weighting, and time
  93          * weighting. */
  94         mode = devc->buf[2] & 0x0f;
  95         switch (mode) {
  96                 case 0x0:
  97                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_A \
  98                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
  99                         break;
 100                 case 0x1:
 101                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 102                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 103                         break;
 104                 case 0x2:
 105                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_C \
 106                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 107                         break;
 108                 case 0x3:
 109                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_C \
 110                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 111                         break;
 112                 case 0x4:
 113                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT \
 114                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 115                         break;
 116                 case 0x5:
 117                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT \
 118                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 119                         break;
 120                 case 0x6:
 121                         analog.mqflags |= SR_MQFLAG_SPL_PCT_OVER_ALARM \
 122                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 123                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 124                         break;
 125                 case 0x7:
 126                         analog.mqflags |= SR_MQFLAG_SPL_PCT_OVER_ALARM \
 127                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 128                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 129                         break;
 130                 case 0x8:
 131                         /* 10-second mean, but we don't have MQ flags to express it. */
 132                         analog.mqflags |= SR_MQFLAG_SPL_LAT \
 133                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 134                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 135                         break;
 136                 case 0x9:
 137                         /* Mean over a time period between 11 seconds and 24 hours.
 138                          * Which is so silly that there's no point in expressing
 139                          * either this or the previous case.  */
 140                         analog.mqflags |= SR_MQFLAG_SPL_LAT \
 141                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 142                                         | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 143                         break;
 144                 case 0xa:
 145                         /* 10-second mean. */
 146                         analog.mqflags |= SR_MQFLAG_SPL_LAT \
 147                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 148                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 149                         break;
 150                 case 0xb:
 151                         /* Mean over a time period between 11 seconds and 24 hours. */
 152                         analog.mqflags |= SR_MQFLAG_SPL_LAT \
 153                                         | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 154                                         | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 155                         break;
 156                 case 0xc:
 157                         /* Internal calibration on 1kHz sine at 94dB, not useful
 158                          * to anything but the device. */
 159                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT;
 160                         break;
 161                 case 0xd:
 162                         /* Internal calibration on 1kHz sine at 94dB, not useful
 163                          * to anything but the device. */
 164                         analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT;
 165                         break;
 166                 default:
 167                         sr_dbg("unknown configuration 0x%.2x", mode);
 168                         return;
 169                         break;
 170         }
 171
 172         packet.type = SR_DF_ANALOG;
 173         packet.payload = &analog;
 174         sr_session_send(devc->cb_data, &packet);
 175
 176         devc->num_samples++;
 177
 178 }
 179
 180 SR_PRIV int colead_slm_receive_data(int fd, int revents, void *cb_data)
 181 {
 182         const struct sr_dev_inst *sdi;
 183         struct dev_context *devc;
 184         int len;
 185         char buf[128];
 186
 187         (void)fd;
 188
 189         if (!(sdi = cb_data))
 190                 return TRUE;
 191
 192         if (!(devc = sdi->priv))
 193                 return TRUE;
 194
 195         if (revents != G_IO_IN)
 196                 /* Timeout event. */
 197                 return TRUE;
 198
 199         if (devc->state == IDLE) {
 200                 if (serial_read(devc->serial, buf, 128) != 1 || buf[0] != 0x10)
 201                         /* Nothing there, or caught the tail end of a previous packet,
 202                          * or some garbage. Unless it's a single "data ready" byte,
 203                          * we don't want it. */
 204                         return TRUE;
 205                 /* Got 0x10, "measurement ready". */
 206                 if (serial_write(devc->serial, "\x20", 1) == -1)
 207                         sr_err("unable to send command: %s", strerror(errno));
 208                 else {
 209                         devc->state = COMMAND_SENT;
 210                         devc->buflen = 0;
 211                 }
 212         } else {
 213                 len = serial_read(devc->serial, devc->buf + devc->buflen,
 214                                 10 - devc->buflen);
 215                 if (len < 1)
 216                         return TRUE;
 217                 devc->buflen += len;
 218                 if (devc->buflen > 10) {
 219                         sr_dbg("buffer overrun");
 220                         devc->state = IDLE;
 221                         return TRUE;
 222                 }
 223                 if (devc->buflen == 10) {
 224                         /* If we got here, we're sure the device sent a "data ready"
 225                          * notification, we asked for data, and got it. */
 226                         process_packet(sdi);
 227                         devc->state = IDLE;
 228                 }
 229         }
 230
 231         return TRUE;
 232 }
 233