/****************************************************************************
*
* Copyright (c) 2013-2014 PX4 Development Team. All rights reserved.
* Author: Stefan Rado <px4@sradonia.net>
*
* 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 frsky_telemetry.c
* @author Stefan Rado <px4@sradonia.net>
*
* FrSky telemetry implementation.
*
* This daemon emulates an FrSky sensor hub by periodically sending data
* packets to an attached FrSky receiver.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <systemlib/err.h>
#include <systemlib/systemlib.h>
#include <termios.h>
#include "frsky_data.h"
/* thread state */
static volatile bool thread_should_exit = false;
static volatile bool thread_running = false;
static int frsky_task;
/* functions */
static int frsky_open_uart(const char *uart_name, struct termios *uart_config_original);
static void usage(void);
static int frsky_telemetry_thread_main(int argc, char *argv[]);
__EXPORT int frsky_telemetry_main(int argc, char *argv[]);
/**
* Opens the UART device and sets all required serial parameters.
*/
static int frsky_open_uart(const char *uart_name, struct termios *uart_config_original)
{
/* Open UART */
const int uart = open(uart_name, O_WRONLY | O_NOCTTY);
if (uart < 0) {
err(1, "Error opening port: %s", uart_name);
}
/* Back up the original UART configuration to restore it after exit */
int termios_state;
if ((termios_state = tcgetattr(uart, uart_config_original)) < 0) {
warnx("ERR: tcgetattr%s: %d\n", uart_name, termios_state);
close(uart);
return -1;
}
/* Fill the struct for the new configuration */
struct termios uart_config;
tcgetattr(uart, &uart_config);
/* Disable output post-processing */
uart_config.c_oflag &= ~OPOST;
/* Set baud rate */
static const speed_t speed = B9600;
if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
warnx("ERR: %s: %d (cfsetispeed, cfsetospeed)\n", uart_name, termios_state);
close(uart);
return -1;
}
if ((termios_state = tcsetattr(uart, TCSANOW, &uart_config)) < 0) {
warnx("ERR: %s (tcsetattr)\n", uart_name);
close(uart);
return -1;
}
return uart;
}
/**
* Print command usage information
*/
static void usage()
{
fprintf(stderr,
"usage: frsky_telemetry start [-d <devicename>]\n"
" frsky_telemetry stop\n"
" frsky_telemetry status\n");
exit(1);
}
/**
* The daemon thread.
*/
static int frsky_telemetry_thread_main(int argc, char *argv[])
{
/* Default values for arguments */
char *device_name = "/dev/ttyS1"; /* USART2 */
/* Work around some stupidity in task_create's argv handling */
argc -= 2;
argv += 2;
int ch;
while ((ch = getopt(argc, argv, "d:")) != EOF) {
switch (ch) {
case 'd':
device_name = optarg;
break;
default:
usage();
break;
}
}
/* Open UART */
struct termios uart_config_original;
const int uart = frsky_open_uart(device_name, &uart_config_original);
if (uart < 0)
err(1, "could not open %s", device_name);
/* Subscribe to topics */
frsky_init();
thread_running = true;
/* Main thread loop */
unsigned int iteration = 0;
while (!thread_should_exit) {
/* Sleep 200 ms */
usleep(200000);
/* Send frame 1 (every 200ms): acceleration values, altitude (vario), temperatures, current & voltages, RPM */
frsky_send_frame1(uart);
/* Send frame 2 (every 1000ms): course, latitude, longitude, speed, altitude (GPS), fuel level */
if (iteration % 5 == 0)
{
frsky_send_frame2(uart);
}
/* Send frame 3 (every 5000ms): date, time */
if (iteration % 25 == 0)
{
frsky_send_frame3(uart);
iteration = 0;
}
iteration++;
}
/* Reset the UART flags to original state */
tcsetattr(uart, TCSANOW, &uart_config_original);
close(uart);
thread_running = false;
return 0;
}
/**
* The main command function.
* Processes command line arguments and starts the daemon.
*/
int frsky_telemetry_main(int argc, char *argv[])
{
if (argc < 2) {
warnx("missing command");
usage();
}
if (!strcmp(argv[1], "start")) {
/* this is not an error */
if (thread_running)
errx(0, "frsky_telemetry already running");
thread_should_exit = false;
frsky_task = task_spawn_cmd("frsky_telemetry",
SCHED_DEFAULT,
SCHED_PRIORITY_DEFAULT,
2000,
frsky_telemetry_thread_main,
(char * const *)argv);
while (!thread_running) {
usleep(200);
}
exit(0);
}
if (!strcmp(argv[1], "stop")) {
/* this is not an error */
if (!thread_running)
errx(0, "frsky_telemetry already stopped");
thread_should_exit = true;
while (thread_running) {
usleep(200000);
warnx(".");
}
warnx("terminated.");
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (thread_running) {
errx(0, "running");
} else {
errx(1, "not running");
}
}
warnx("unrecognized command");
usage();
/* not getting here */
return 0;
}
