/****************************************************************************
*
* Copyright (c) 2012, 2013 PX4 Development Team. All rights reserved.
* Author: Simon Wilks <sjwilks@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file hott_telemetry_main.c
* @author Simon Wilks <sjwilks@gmail.com>
*
* Graupner HoTT Telemetry implementation.
*
* The HoTT receiver polls each device at a regular interval at which point
* a data packet can be returned if necessary.
*
*/
#include <fcntl.h>
#include <nuttx/config.h>
#include <poll.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <systemlib/err.h>
#include <systemlib/systemlib.h>
#include "../comms.h"
#include "../messages.h"
#define DEFAULT_UART "/dev/ttyS0"; /**< USART1 */
/* Oddly, ERROR is not defined for C++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;
static int thread_should_exit = false; /**< Deamon exit flag */
static int thread_running = false; /**< Deamon status flag */
static int deamon_task; /**< Handle of deamon task / thread */
static const char daemon_name[] = "hott_telemetry";
static const char commandline_usage[] = "usage: hott_telemetry start|status|stop [-d <device>]";
/**
* Deamon management function.
*/
extern "C" __EXPORT int hott_telemetry_main(int argc, char *argv[]);
/**
* Mainloop of daemon.
*/
int hott_telemetry_thread_main(int argc, char *argv[]);
static int recv_req_id(int uart, uint8_t *id);
static int send_data(int uart, uint8_t *buffer, size_t size);
int
recv_req_id(int uart, uint8_t *id)
{
static const int timeout_ms = 1000; // TODO make it a define
uint8_t mode;
struct pollfd fds;
fds.fd = uart;
fds.events = POLLIN;
if (poll(&fds, 1, timeout_ms) > 0) {
/* Get the mode: binary or text */
read(uart, &mode, sizeof(mode));
/* if we have a binary mode request */
if (mode != BINARY_MODE_REQUEST_ID) {
return ERROR;
}
/* Read the device ID being polled */
read(uart, id, sizeof(*id));
} else {
warnx("UART timeout on TX/RX port");
return ERROR;
}
return OK;
}
int
send_data(int uart, uint8_t *buffer, size_t size)
{
usleep(POST_READ_DELAY_IN_USECS);
uint16_t checksum = 0;
for (size_t i = 0; i < size; i++) {
if (i == size - 1) {
/* Set the checksum: the first uint8_t is taken as the checksum. */
buffer[i] = checksum & 0xff;
} else {
checksum += buffer[i];
}
write(uart, &buffer[i], sizeof(buffer[i]));
/* Sleep before sending the next byte. */
usleep(POST_WRITE_DELAY_IN_USECS);
}
/* A hack the reads out what was written so the next read from the receiver doesn't get it. */
/* TODO: Fix this!! */
uint8_t dummy[size];
read(uart, &dummy, size);
return OK;
}
int
hott_telemetry_thread_main(int argc, char *argv[])
{
warnx("starting");
thread_running = true;
const char *device = DEFAULT_UART;
/* read commandline arguments */
for (int i = 0; i < argc && argv[i]; i++) {
if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--device") == 0) { //device set
if (argc > i + 1) {
device = argv[i + 1];
} else {
thread_running = false;
errx(1, "missing parameter to -d\n%s", commandline_usage);
}
}
}
/* enable UART, writes potentially an empty buffer, but multiplexing is disabled */
const int uart = open_uart(device);
if (uart < 0) {
errx(1, "Failed opening HoTT UART, exiting.");
thread_running = false;
}
init_sub_messages();
uint8_t buffer[MAX_MESSAGE_BUFFER_SIZE];
size_t size = 0;
uint8_t id = 0;
bool connected = true;
while (!thread_should_exit) {
// Listen for and serve poll from the receiver.
if (recv_req_id(uart, &id) == OK) {
if (!connected) {
connected = true;
warnx("OK");
}
switch (id) {
case EAM_SENSOR_ID:
build_eam_response(buffer, &size);
break;
case GAM_SENSOR_ID:
build_gam_response(buffer, &size);
break;
case GPS_SENSOR_ID:
build_gps_response(buffer, &size);
break;
default:
continue; // Not a module we support.
}
send_data(uart, buffer, size);
} else {
connected = false;
warnx("syncing");
}
}
warnx("exiting");
close(uart);
thread_running = false;
return 0;
}
/**
* Process command line arguments and start the daemon.
*/
int
hott_telemetry_main(int argc, char *argv[])
{
if (argc < 1) {
errx(1, "missing command\n%s", commandline_usage);
}
if (!strcmp(argv[1], "start")) {
if (thread_running) {
warnx("already running");
exit(0);
}
thread_should_exit = false;
deamon_task = task_spawn_cmd(daemon_name,
SCHED_DEFAULT,
SCHED_PRIORITY_DEFAULT,
2048,
hott_telemetry_thread_main,
(argv) ? (const char **)&argv[2] : (const char **)NULL);
exit(0);
}
if (!strcmp(argv[1], "stop")) {
thread_should_exit = true;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (thread_running) {
warnx("is running");
} else {
warnx("not started");
}
exit(0);
}
errx(1, "unrecognized command\n%s", commandline_usage);
}
