hardware/testo/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2014 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 <string.h>
  21 #include "protocol.h"
  22
  23 SR_PRIV int testo_set_serial_params(struct sr_usb_dev_inst *usb)
  24 {
  25         int ret;
  26
  27     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_BAUDRATE,
  28                         FTDI_BAUDRATE_115200, FTDI_INDEX, NULL, 0, 10)) < 0) {
  29                         sr_err("Failed to set baudrate: %s", libusb_error_name(ret));
  30                         return SR_ERR;
  31         }
  32
  33     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_PARAMS,
  34                         FTDI_PARAMS_8N1, FTDI_INDEX, NULL, 0, 10)) < 0) {
  35                         sr_err("Failed to set comm parameters: %s", libusb_error_name(ret));
  36                         return SR_ERR;
  37         }
  38
  39     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_FLOWCTRL,
  40                         FTDI_FLOW_NONE, FTDI_INDEX, NULL, 0, 10)) < 0) {
  41                         sr_err("Failed to set flow control: %s", libusb_error_name(ret));
  42                         return SR_ERR;
  43         }
  44
  45     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_MODEMCTRL,
  46                         FTDI_MODEM_ALLHIGH, FTDI_INDEX, NULL, 0, 10)) < 0) {
  47                         sr_err("Failed to set modem control: %s", libusb_error_name(ret));
  48                         return SR_ERR;
  49         }
  50
  51         return SR_OK;
  52 }
  53
  54 /* Due to the modular nature of the Testo hardware, you can't assume
  55  * which measurements the device will supply. Fetch a single result
  56  * set synchronously to see which measurements it has. */
  57 SR_PRIV int testo_probe_channels(struct sr_dev_inst *sdi)
  58 {
  59         struct dev_context *devc;
  60         struct sr_usb_dev_inst *usb;
  61         struct sr_channel *ch;
  62         int unit, packet_len, len, i;
  63         unsigned char packet[MAX_REPLY_SIZE], buf[MAX_REPLY_SIZE];
  64         char *probe_name;
  65
  66         devc = sdi->priv;
  67         usb = sdi->conn;
  68
  69         if (sdi->driver->dev_open(sdi) != SR_OK)
  70                 return SR_ERR;
  71         if (testo_set_serial_params(usb) != SR_OK)
  72                 return SR_ERR;
  73         if (libusb_bulk_transfer(usb->devhdl, EP_OUT, devc->model->request,
  74                         devc->model->request_size, &devc->reply_size, 10) < 0)
  75                 return SR_ERR;
  76         packet_len = 0;
  77         while(TRUE) {
  78                 if (libusb_bulk_transfer(usb->devhdl, EP_IN, buf, MAX_REPLY_SIZE,
  79                                 &len, 250) < 0)
  80                         return SR_ERR;
  81                 if (len == 2)
  82                         /* FTDI cruft */
  83                         continue;
  84                 sr_dbg("got %d", len);
  85                 if (packet_len + len - 2 > MAX_REPLY_SIZE)
  86                         return SR_ERR;
  87                 memcpy(packet + packet_len, buf + 2, len - 2);
  88                 packet_len += len - 2;
  89
  90                 if (packet_len >= 7) {
  91                         if (!testo_check_packet(packet, packet_len))
  92                                 return SR_ERR;
  93                         if (packet_len >= 7 + packet[6] * 7 + 2)
  94                                 /* Got a complete packet. */
  95                                 break;
  96                 }
  97         }
  98
  99         if (packet[6] > MAX_CHANNELS) {
 100                 sr_err("Device says it has %d channels!", packet[6]);
 101                 return SR_ERR;
 102         }
 103
 104         for (i = 0; i < packet[6]; i++) {
 105                 unit = packet[7 + i * 7 + 4];
 106                 devc->channel_units[i] = unit;
 107                 switch (unit) {
 108                 case 1:
 109                         probe_name = "Temperature";
 110                         break;
 111                 case 3:
 112                         probe_name = "Humidity";
 113                         break;
 114                 case 5:
 115                         probe_name = "Windspeed";
 116                         break;
 117                 case 24:
 118                         probe_name = "Pressure";
 119                         break;
 120                 default:
 121                         sr_dbg("Unsupported measurement unit %d", unit);
 122                         return SR_ERR;
 123                 }
 124                 ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, probe_name);
 125                 sdi->channels = g_slist_append(sdi->channels, ch);
 126         }
 127         devc->num_channels = packet[6];
 128
 129         sdi->driver->dev_close(sdi);
 130
 131         return SR_OK;
 132 }
 133
 134 SR_PRIV int testo_request_packet(const struct sr_dev_inst *sdi)
 135 {
 136         struct dev_context *devc;
 137         struct sr_usb_dev_inst *usb;
 138         int ret;
 139
 140         devc = sdi->priv;
 141         usb = sdi->conn;
 142
 143         libusb_fill_bulk_transfer(devc->out_transfer, usb->devhdl, EP_OUT,
 144                         devc->model->request, devc->model->request_size,
 145                         receive_transfer, (void *)sdi, 100);
 146         if ((ret = libusb_submit_transfer(devc->out_transfer) != 0)) {
 147                 sr_err("Failed to request packet: %s.", libusb_error_name(ret));
 148                 sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
 149                                 devc->cb_data);
 150                 return SR_ERR;
 151         }
 152         sr_dbg("Requested new packet.");
 153
 154         return SR_OK;
 155 }
 156
 157 /* Check if the packet is well-formed. This matches packets for the
 158  * Testo 175/177/400/650/950/435/635/735/445/645/945/946/545. */
 159 SR_PRIV gboolean testo_check_packet(unsigned char *buf, int len)
 160 {
 161         int i;
 162         unsigned char check[] = { 0x21, 0, 0, 0, 1 };
 163
 164         if (len < 5)
 165                 return FALSE;
 166
 167         for (i = 0; i < 5; i++) {
 168                 if (buf[i] != check[i]) {
 169                         sr_dbg("Packet has invalid prefix.");
 170                         return FALSE;
 171                 }
 172         }
 173
 174         /* TODO: check FCS, algorithm corresponds to python crcmod crc-16-mcrf4xx */
 175
 176         return TRUE;
 177 }
 178
 179 static float binary32_le_to_float(unsigned char *buf)
 180 {
 181         GFloatIEEE754 f;
 182
 183         f.v_float = 0;
 184         f.mpn.sign = (buf[3] & 0x80) ? 1 : 0;
 185         f.mpn.biased_exponent = (buf[3] << 1) | (buf[2] >> 7);
 186         f.mpn.mantissa = buf[0] | (buf[1] << 8) | ((buf[2] & 0x7f) << 16);
 187
 188         return f.v_float;
 189 }
 190
 191 SR_PRIV void testo_receive_packet(const struct sr_dev_inst *sdi)
 192 {
 193         struct dev_context *devc;
 194         struct sr_datafeed_packet packet;
 195         struct sr_datafeed_analog analog;
 196         struct sr_channel *ch;
 197         GString *dbg;
 198         float value;
 199         int i;
 200         unsigned char *buf;
 201
 202         devc = sdi->priv;
 203         sr_dbg("Got %d-byte packet.", devc->reply_size);
 204
 205         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
 206                 dbg = g_string_sized_new(128);
 207                 g_string_printf(dbg, "Packet:");
 208                 for (i = 0; i < devc->reply_size; i++)
 209                         g_string_append_printf(dbg, " %.2x", devc->reply[i]);
 210                 sr_spew("%s", dbg->str);
 211                 g_string_free(dbg, TRUE);
 212         }
 213
 214         if (!testo_check_packet(devc->reply, devc->reply_size))
 215                 return;
 216
 217         packet.type = SR_DF_ANALOG;
 218         packet.payload = &analog;
 219         analog.num_samples = 1;
 220         analog.mqflags = 0;
 221         analog.data = &value;
 222         /* Decode 7-byte values */
 223         for (i = 0; i < devc->reply[6]; i++) {
 224                 buf = devc->reply + 7 + i * 7;
 225                 value = binary32_le_to_float(buf);
 226                 sr_dbg("value: %f unit %d exp %d", value, buf[4], buf[6]);
 227                 switch (buf[4]) {
 228                 case 1:
 229                         analog.mq = SR_MQ_TEMPERATURE;
 230                         analog.unit = SR_UNIT_CELSIUS;
 231                         break;
 232                 case 3:
 233                         analog.mq = SR_MQ_RELATIVE_HUMIDITY;
 234                         analog.unit = SR_UNIT_HUMIDITY_293K;
 235                         break;
 236                 case 5:
 237                         analog.mq = SR_MQ_WIND_SPEED;
 238                         analog.unit = SR_UNIT_METER_SECOND;
 239                         break;
 240                 case 24:
 241                         analog.mq = SR_MQ_PRESSURE;
 242                         analog.unit = SR_UNIT_HECTOPASCAL;
 243                         break;
 244                 default:
 245                         sr_dbg("Unsupported measurement unit %d", buf[4]);
 246                         return;
 247                 }
 248
 249                 /* Match this measurement with its channel. */
 250                 for (i = 0; i < devc->num_channels; i++) {
 251                         if (devc->channel_units[i] == buf[4])
 252                                 break;
 253                 }
 254                 if (i == devc->num_channels) {
 255                         /* Shouldn't happen. */
 256                         sr_err("Some channel hotswapped in!");
 257                         return;
 258                 }
 259                 ch = g_slist_nth_data(sdi->channels, i);
 260                 sr_dbg("channel %d name %s unit %d", i, ch->name, analog.unit);
 261                 analog.channels = g_slist_append(NULL, ch);
 262                 sr_session_send(sdi, &packet);
 263                 g_slist_free(analog.channels);
 264         }
 265 }
 266