src/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 <string.h>
  23 #include <libsigrok/libsigrok.h>
  24 #include "libsigrok-internal.h"
  25 #include "protocol.h"
  26
  27 static void process_packet(const struct sr_dev_inst *sdi)
  28 {
  29         struct dev_context *devc;
  30         struct sr_datafeed_packet packet;
  31         struct sr_datafeed_analog analog;
  32         GString *dbg;
  33         float fvalue;
  34         int checksum, mode, i;
  35
  36         devc = sdi->priv;
  37         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
  38                 dbg = g_string_sized_new(128);
  39                 g_string_printf(dbg, "received packet:");
  40                 for (i = 0; i < 10; i++)
  41                         g_string_append_printf(dbg, " %.2x", (devc->buf)[i]);
  42                 sr_spew("%s", dbg->str);
  43                 g_string_free(dbg, TRUE);
  44         }
  45
  46         if (devc->buf[0] != 0x08 || devc->buf[1] != 0x04) {
  47                 sr_dbg("invalid packet header.");
  48                 return;
  49         }
  50
  51         if (devc->buf[8] != 0x01) {
  52                 sr_dbg("invalid measurement.");
  53                 return;
  54         }
  55
  56         checksum = 0;
  57         for (i = 0; i < 9; i++)
  58                 checksum += devc->buf[i];
  59         if ((checksum & 0xff) != devc->buf[9]) {
  60                 sr_dbg("invalid packet checksum.");
  61                 return;
  62         }
  63
  64         fvalue = 0.0;
  65         for (i = 3; i < 8; i++) {
  66                 if (devc->buf[i] > 0x09)
  67                         continue;
  68                 fvalue *= 10;
  69                 fvalue += devc->buf[i];
  70         }
  71         fvalue /= 10;
  72
  73         memset(&analog, 0, sizeof(struct sr_datafeed_analog));
  74         analog.mq = SR_MQ_SOUND_PRESSURE_LEVEL;
  75         analog.unit = SR_UNIT_DECIBEL_SPL;
  76         analog.channels = sdi->channels;
  77         analog.num_samples = 1;
  78         analog.data = &fvalue;
  79
  80         /* High nibble should only have 0x01 or 0x02. */
  81         mode = (devc->buf[2] >> 4) & 0x0f;
  82         if (mode == 0x02)
  83                 analog.mqflags |= SR_MQFLAG_HOLD;
  84         else if (mode != 0x01) {
  85                 sr_dbg("unknown measurement mode 0x%.2x", mode);
  86                 return;
  87         }
  88
  89         /* Low nibble has 14 combinations of direct/long-term average,
  90          * time scale of that average, frequency weighting, and time
  91          * weighting. */
  92         mode = devc->buf[2] & 0x0f;
  93         switch (mode) {
  94         case 0x0:
  95                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_A \
  96                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
  97                 break;
  98         case 0x1:
  99                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 100                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 101                 break;
 102         case 0x2:
 103                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_C \
 104                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 105                 break;
 106         case 0x3:
 107                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_C \
 108                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 109                 break;
 110         case 0x4:
 111                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT \
 112                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 113                 break;
 114         case 0x5:
 115                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT \
 116                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 117                 break;
 118         case 0x6:
 119                 analog.mqflags |= SR_MQFLAG_SPL_PCT_OVER_ALARM \
 120                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 121                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 122                 break;
 123         case 0x7:
 124                 analog.mqflags |= SR_MQFLAG_SPL_PCT_OVER_ALARM \
 125                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 126                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 127                 break;
 128         case 0x8:
 129                 /* 10-second mean, but we don't have MQ flags to express it. */
 130                 analog.mqflags |= SR_MQFLAG_SPL_LAT \
 131                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 132                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 133                 break;
 134         case 0x9:
 135                 /* Mean over a time period between 11 seconds and 24 hours.
 136                  * Which is so silly that there's no point in expressing
 137                  * either this or the previous case.  */
 138                 analog.mqflags |= SR_MQFLAG_SPL_LAT \
 139                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 140                                 | SR_MQFLAG_SPL_TIME_WEIGHT_F;
 141                 break;
 142         case 0xa:
 143                 /* 10-second mean. */
 144                 analog.mqflags |= SR_MQFLAG_SPL_LAT \
 145                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 146                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 147                 break;
 148         case 0xb:
 149                 /* Mean over a time period between 11 seconds and 24 hours. */
 150                 analog.mqflags |= SR_MQFLAG_SPL_LAT \
 151                                 | SR_MQFLAG_SPL_FREQ_WEIGHT_A \
 152                                 | SR_MQFLAG_SPL_TIME_WEIGHT_S;
 153                 break;
 154         case 0xc:
 155                 /* Internal calibration on 1kHz sine at 94dB, not useful
 156                  * to anything but the device. */
 157                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT;
 158                 break;
 159         case 0xd:
 160                 /* Internal calibration on 1kHz sine at 94dB, not useful
 161                  * to anything but the device. */
 162                 analog.mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT;
 163                 break;
 164         default:
 165                 sr_dbg("unknown configuration 0x%.2x", mode);
 166                 return;
 167         }
 168
 169         packet.type = SR_DF_ANALOG;
 170         packet.payload = &analog;
 171         sr_session_send(devc->cb_data, &packet);
 172
 173         devc->num_samples++;
 174         if (devc->num_samples >= devc->limit_samples)
 175                 sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
 176                                 devc->cb_data);
 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         struct sr_serial_dev_inst *serial;
 185         int delay_ms, len;
 186         char buf[128];
 187
 188         (void)fd;
 189
 190         if (!(sdi = cb_data))
 191                 return TRUE;
 192
 193         if (!(devc = sdi->priv))
 194                 return TRUE;
 195
 196         if (revents != G_IO_IN)
 197                 /* Timeout event. */
 198                 return TRUE;
 199
 200         serial = sdi->conn;
 201         if (devc->state == IDLE) {
 202                 if (serial_read_nonblocking(serial, buf, 128) != 1 || buf[0] != 0x10)
 203                         /* Nothing there, or caught the tail end of a previous packet,
 204                          * or some garbage. Unless it's a single "data ready" byte,
 205                          * we don't want it. */
 206                         return TRUE;
 207                 /* Got 0x10, "measurement ready". */
 208                 delay_ms = serial_timeout(serial, 1);
 209                 if (serial_write_blocking(serial, "\x20", 1, delay_ms) < 1)
 210                         sr_err("unable to send command");
 211                 else {
 212                         devc->state = COMMAND_SENT;
 213                         devc->buflen = 0;
 214                 }
 215         } else {
 216                 len = serial_read_nonblocking(serial, devc->buf + devc->buflen,
 217                                 10 - devc->buflen);
 218                 if (len < 1)
 219                         return TRUE;
 220                 devc->buflen += len;
 221                 if (devc->buflen > 10) {
 222                         sr_dbg("buffer overrun");
 223                         devc->state = IDLE;
 224                         return TRUE;
 225                 }
 226                 if (devc->buflen == 10) {
 227                         /* If we got here, we're sure the device sent a "data ready"
 228                          * notification, we asked for data, and got it. */
 229                         process_packet(sdi);
 230                         devc->state = IDLE;
 231                 }
 232         }
 233
 234         return TRUE;
 235 }