libsigrok/hardware/testo/protocol.c

267 lines
7.0 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2014 Bert Vermeulen <bert@biot.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 <string.h>
#include "protocol.h"
SR_PRIV int testo_set_serial_params(struct sr_usb_dev_inst *usb)
{
int ret;
if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_BAUDRATE,
FTDI_BAUDRATE_115200, FTDI_INDEX, NULL, 0, 10)) < 0) {
sr_err("Failed to set baudrate: %s", libusb_error_name(ret));
return SR_ERR;
}
if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_PARAMS,
FTDI_PARAMS_8N1, FTDI_INDEX, NULL, 0, 10)) < 0) {
sr_err("Failed to set comm parameters: %s", libusb_error_name(ret));
return SR_ERR;
}
if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_FLOWCTRL,
FTDI_FLOW_NONE, FTDI_INDEX, NULL, 0, 10)) < 0) {
sr_err("Failed to set flow control: %s", libusb_error_name(ret));
return SR_ERR;
}
if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_MODEMCTRL,
FTDI_MODEM_ALLHIGH, FTDI_INDEX, NULL, 0, 10)) < 0) {
sr_err("Failed to set modem control: %s", libusb_error_name(ret));
return SR_ERR;
}
return SR_OK;
}
/* Due to the modular nature of the Testo hardware, you can't assume
* which measurements the device will supply. Fetch a single result
* set synchronously to see which measurements it has. */
SR_PRIV int testo_probe_channels(struct sr_dev_inst *sdi)
{
struct dev_context *devc;
struct sr_usb_dev_inst *usb;
struct sr_channel *ch;
int unit, packet_len, len, i;
unsigned char packet[MAX_REPLY_SIZE], buf[MAX_REPLY_SIZE];
char *probe_name;
devc = sdi->priv;
usb = sdi->conn;
if (sdi->driver->dev_open(sdi) != SR_OK)
return SR_ERR;
if (testo_set_serial_params(usb) != SR_OK)
return SR_ERR;
if (libusb_bulk_transfer(usb->devhdl, EP_OUT, devc->model->request,
devc->model->request_size, &devc->reply_size, 10) < 0)
return SR_ERR;
packet_len = 0;
while(TRUE) {
if (libusb_bulk_transfer(usb->devhdl, EP_IN, buf, MAX_REPLY_SIZE,
&len, 250) < 0)
return SR_ERR;
if (len == 2)
/* FTDI cruft */
continue;
sr_dbg("got %d", len);
if (packet_len + len - 2 > MAX_REPLY_SIZE)
return SR_ERR;
memcpy(packet + packet_len, buf + 2, len - 2);
packet_len += len - 2;
if (packet_len >= 7) {
if (!testo_check_packet(packet, packet_len))
return SR_ERR;
if (packet_len >= 7 + packet[6] * 7 + 2)
/* Got a complete packet. */
break;
}
}
if (packet[6] > MAX_CHANNELS) {
sr_err("Device says it has %d channels!", packet[6]);
return SR_ERR;
}
for (i = 0; i < packet[6]; i++) {
unit = packet[7 + i * 7 + 4];
devc->channel_units[i] = unit;
switch (unit) {
case 1:
probe_name = "Temperature";
break;
case 3:
probe_name = "Humidity";
break;
case 5:
probe_name = "Windspeed";
break;
case 24:
probe_name = "Pressure";
break;
default:
sr_dbg("Unsupported measurement unit %d", unit);
return SR_ERR;
}
ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, probe_name);
sdi->channels = g_slist_append(sdi->channels, ch);
}
devc->num_channels = packet[6];
sdi->driver->dev_close(sdi);
return SR_OK;
}
SR_PRIV int testo_request_packet(const struct sr_dev_inst *sdi)
{
struct dev_context *devc;
struct sr_usb_dev_inst *usb;
int ret;
devc = sdi->priv;
usb = sdi->conn;
libusb_fill_bulk_transfer(devc->out_transfer, usb->devhdl, EP_OUT,
devc->model->request, devc->model->request_size,
receive_transfer, (void *)sdi, 100);
if ((ret = libusb_submit_transfer(devc->out_transfer) != 0)) {
sr_err("Failed to request packet: %s.", libusb_error_name(ret));
sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
devc->cb_data);
return SR_ERR;
}
sr_dbg("Requested new packet.");
return SR_OK;
}
/* Check if the packet is well-formed. This matches packets for the
* Testo 175/177/400/650/950/435/635/735/445/645/945/946/545. */
SR_PRIV gboolean testo_check_packet(unsigned char *buf, int len)
{
int i;
unsigned char check[] = { 0x21, 0, 0, 0, 1 };
if (len < 5)
return FALSE;
for (i = 0; i < 5; i++) {
if (buf[i] != check[i]) {
sr_dbg("Packet has invalid prefix.");
return FALSE;
}
}
/* TODO: check FCS, algorithm corresponds to python crcmod crc-16-mcrf4xx */
return TRUE;
}
static float binary32_le_to_float(unsigned char *buf)
{
GFloatIEEE754 f;
f.v_float = 0;
f.mpn.sign = (buf[3] & 0x80) ? 1 : 0;
f.mpn.biased_exponent = (buf[3] << 1) | (buf[2] >> 7);
f.mpn.mantissa = buf[0] | (buf[1] << 8) | ((buf[2] & 0x7f) << 16);
return f.v_float;
}
SR_PRIV void testo_receive_packet(const struct sr_dev_inst *sdi)
{
struct dev_context *devc;
struct sr_datafeed_packet packet;
struct sr_datafeed_analog analog;
struct sr_channel *ch;
GString *dbg;
float value;
int i;
unsigned char *buf;
devc = sdi->priv;
sr_dbg("Got %d-byte packet.", devc->reply_size);
if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
dbg = g_string_sized_new(128);
g_string_printf(dbg, "Packet:");
for (i = 0; i < devc->reply_size; i++)
g_string_append_printf(dbg, " %.2x", devc->reply[i]);
sr_spew("%s", dbg->str);
g_string_free(dbg, TRUE);
}
if (!testo_check_packet(devc->reply, devc->reply_size))
return;
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
analog.num_samples = 1;
analog.mqflags = 0;
analog.data = &value;
/* Decode 7-byte values */
for (i = 0; i < devc->reply[6]; i++) {
buf = devc->reply + 7 + i * 7;
value = binary32_le_to_float(buf);
sr_dbg("value: %f unit %d exp %d", value, buf[4], buf[6]);
switch (buf[4]) {
case 1:
analog.mq = SR_MQ_TEMPERATURE;
analog.unit = SR_UNIT_CELSIUS;
break;
case 3:
analog.mq = SR_MQ_RELATIVE_HUMIDITY;
analog.unit = SR_UNIT_HUMIDITY_293K;
break;
case 5:
analog.mq = SR_MQ_WIND_SPEED;
analog.unit = SR_UNIT_METER_SECOND;
break;
case 24:
analog.mq = SR_MQ_PRESSURE;
analog.unit = SR_UNIT_HECTOPASCAL;
break;
default:
sr_dbg("Unsupported measurement unit %d", buf[4]);
return;
}
/* Match this measurement with its channel. */
for (i = 0; i < devc->num_channels; i++) {
if (devc->channel_units[i] == buf[4])
break;
}
if (i == devc->num_channels) {
/* Shouldn't happen. */
sr_err("Some channel hotswapped in!");
return;
}
ch = g_slist_nth_data(sdi->channels, i);
sr_dbg("channel %d name %s unit %d", i, ch->name, analog.unit);
analog.channels = g_slist_append(NULL, ch);
sr_session_send(sdi, &packet);
g_slist_free(analog.channels);
}
}