/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
* Author: Julian Oes <joes@student.ethz.ch>
* Thomas Gubler <thomasgubler@student.ethz.ch>
*
* 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 NMEA protocol implementation */
#include "gps.h"
#include "nmea_helper.h"
#include <sys/prctl.h>
#include <poll.h>
#include <uORB/uORB.h>
#include <uORB/topics/vehicle_gps_position.h>
#include <mavlink/mavlink_log.h>
#define NMEA_HEALTH_SUCCESS_COUNTER_LIMIT 2
#define NMEA_HEALTH_FAIL_COUNTER_LIMIT 2
#define NMEA_BUFFER_SIZE 1000
pthread_mutex_t *nmea_mutex;
gps_bin_nmea_state_t *nmea_state;
static struct vehicle_gps_position_s *nmea_gps;
extern bool gps_mode_try_all;
extern bool gps_mode_success;
extern bool terminate_gps_thread;
extern bool gps_baud_try_all;
extern bool gps_verbose;
extern int current_gps_speed;
int read_gps_nmea(int fd, char *gps_rx_buffer, int buffer_size, nmeaINFO *info, nmeaPARSER *parser)
{
int ret = 1;
char c;
int start_flag = 0;
int found_cr = 0;
int rx_count = 0;
int gpsRxOverflow = 0;
struct pollfd fds;
fds.fd = fd;
fds.events = POLLIN;
// NMEA or SINGLE-SENTENCE GPS mode
while (!gps_thread_should_exit) {
//check if the thread should terminate
if (terminate_gps_thread == true) {
// printf("terminate_gps_thread=%u ", terminate_gps_thread);
// printf("exiting mtk thread\n");
// fflush(stdout);
ret = 2;
break;
}
if (poll(&fds, 1, 1000) > 0) {
if (read(fd, &c, 1) > 0) {
// detect start while acquiring stream
// printf("Char = %c\n", c);
if (!start_flag && (c == '$')) {
start_flag = 1;
found_cr = 0;
rx_count = 0;
} else if (!start_flag) { // keep looking for start sign
continue;
}
if (rx_count >= buffer_size) {
// The buffer is already full and we haven't found a valid NMEA sentence.
// Flush the buffer and note the overflow event.
gpsRxOverflow++;
start_flag = 0;
found_cr = 0;
rx_count = 0;
if (gps_verbose) printf("\t[gps] Buffer full\n");
} else {
// store chars in buffer
gps_rx_buffer[rx_count] = c;
rx_count++;
}
// look for carriage return CR
if (start_flag && c == 0x0d) {
found_cr = 1;
}
// and then look for line feed LF
if (start_flag && found_cr && c == 0x0a) {
// parse one NMEA line, use buffer up to rx_count
if (nmea_parse(parser, gps_rx_buffer, rx_count, info) > 0) {
ret = 0;
}
break;
}
} else {
break;
}
} else {
break;
}
}
// As soon as one NMEA message has been parsed, we break out of the loop and end here
return(ret);
}
/**
* \brief Convert NDEG (NMEA degree) to fractional degree
*/
float ndeg2degree(float val)
{
float deg = ((int)(val / 100));
val = deg + (val - deg * 100) / 60;
return val;
}
void *nmea_loop(void *arg)
{
/* Set thread name */
prctl(PR_SET_NAME, "gps nmea read", getpid());
/* Retrieve file descriptor */
int fd = *((int *)arg);
/* Initialize gps stuff */
nmeaINFO info_d;
nmeaINFO *info = &info_d;
char gps_rx_buffer[NMEA_BUFFER_SIZE];
/* gps parser (nmea) */
nmeaPARSER parser;
nmea_parser_init(&parser);
nmea_zero_INFO(info);
/* advertise GPS topic */
struct vehicle_gps_position_s nmea_gps_d = {0};
nmea_gps = &nmea_gps_d;
orb_advert_t gps_handle = orb_advertise(ORB_ID(vehicle_gps_position), nmea_gps);
while (!gps_thread_should_exit) {
/* Parse a message from the gps receiver */
uint8_t read_res = read_gps_nmea(fd, gps_rx_buffer, NMEA_BUFFER_SIZE, info, &parser);
if (0 == read_res) {
/* convert data, ready it for publishing */
/* convert nmea utc time to usec */
struct tm timeinfo;
timeinfo.tm_year = info->utc.year;
timeinfo.tm_mon = info->utc.mon;
timeinfo.tm_mday = info->utc.day;
timeinfo.tm_hour = info->utc.hour;
timeinfo.tm_min = info->utc.min;
timeinfo.tm_sec = info->utc.sec;
time_t epoch = mktime(&timeinfo);
// printf("%d.%d.%d %d:%d:%d:%d\n", timeinfo.tm_year, timeinfo.tm_mon, timeinfo.tm_mday, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec, info->utc.hsec);
nmea_gps->timestamp = hrt_absolute_time();
nmea_gps->time_gps_usec = epoch * 1e6 + info->utc.hsec * 1e4;
nmea_gps->fix_type = (uint8_t)info->fix;
nmea_gps->lat = (int32_t)(ndeg2degree(info->lat) * 1e7);
nmea_gps->lon = (int32_t)(ndeg2degree(info->lon) * 1e7);
nmea_gps->alt = (int32_t)(info->elv * 1e3);
nmea_gps->eph = (uint16_t)(info->HDOP * 100); //TODO:test scaling
nmea_gps->epv = (uint16_t)(info->VDOP * 100); //TODO:test scaling
nmea_gps->vel = (uint16_t)(info->speed * 1000 / 36); //*1000/3600*100
nmea_gps->cog = 65535;
nmea_gps->satellites_visible = (uint8_t)info->satinfo.inview;
int i = 0;
/* Write info about individual satellites */
for (i = 0; i < 12; i++) {
nmea_gps->satellite_prn[i] = (uint8_t)info->satinfo.sat[i].id;
nmea_gps->satellite_used[i] = (uint8_t)info->satinfo.sat[i].in_use;
nmea_gps->satellite_elevation[i] = (uint8_t)info->satinfo.sat[i].elv;
nmea_gps->satellite_azimuth[i] = (uint8_t)info->satinfo.sat[i].azimuth;
nmea_gps->satellite_snr[i] = (uint8_t)info->satinfo.sat[i].sig;
}
if (nmea_gps->satellites_visible > 0) {
nmea_gps->satellite_info_available = 1;
} else {
nmea_gps->satellite_info_available = 0;
}
nmea_gps->counter_pos_valid++;
nmea_gps->timestamp = hrt_absolute_time();
nmea_gps->counter++;
pthread_mutex_lock(nmea_mutex);
nmea_state->last_message_timestamp = hrt_absolute_time();
pthread_mutex_unlock(nmea_mutex);
/* publish new GPS position */
orb_publish(ORB_ID(vehicle_gps_position), gps_handle, nmea_gps);
} else if (read_res == 2) { //termination
/* de-advertise */
close(gps_handle);
break;
}
}
//destroy gps parser
nmea_parser_destroy(&parser);
return NULL;
}
void *nmea_watchdog_loop(void *arg)
{
/* Set thread name */
prctl(PR_SET_NAME, "gps nmea watchdog", getpid());
bool nmea_healthy = false;
uint8_t nmea_fail_count = 0;
uint8_t nmea_success_count = 0;
bool once_ok = false;
int mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
while (!gps_thread_should_exit) {
// printf("nmea_watchdog_loop : while ");
/* if we have no update for a long time print warning (in nmea mode there is no reconfigure) */
pthread_mutex_lock(nmea_mutex);
uint64_t timestamp_now = hrt_absolute_time();
bool all_okay = true;
if (timestamp_now - nmea_state->last_message_timestamp > NMEA_WATCHDOG_CRITICAL_TIME_MICROSECONDS) {
all_okay = false;
}
pthread_mutex_unlock(nmea_mutex);
if (!all_okay) {
/* gps error */
nmea_fail_count++;
// printf("nmea error, nmea_fail_count=%u\n", nmea_fail_count);
// fflush(stdout);
/* If we have too many failures and another mode or baud should be tried, exit... */
if ((gps_mode_try_all == true || gps_baud_try_all == true) && (nmea_fail_count >= NMEA_HEALTH_FAIL_COUNTER_LIMIT) && (nmea_healthy == false) && once_ok == false) {
if (gps_verbose) printf("\t[gps] no NMEA module found\n");
gps_mode_success = false;
break;
}
if (nmea_healthy && nmea_fail_count >= NMEA_HEALTH_FAIL_COUNTER_LIMIT) {
printf("\t[gps] ERROR: NMEA GPS module stopped responding\n");
// global_data_send_subsystem_info(&nmea_present_enabled);
mavlink_log_critical(mavlink_fd, "[gps] NMEA module stopped responding\n");
nmea_healthy = false;
nmea_success_count = 0;
}
fflush(stdout);
sleep(1);
} else {
/* gps healthy */
// printf("\t[gps] nmea success\n");
nmea_success_count++;
if (!nmea_healthy && nmea_success_count >= NMEA_HEALTH_SUCCESS_COUNTER_LIMIT) {
printf("[gps] NMEA module found, status ok (baud=%d)\r\n", current_gps_speed);
// global_data_send_subsystem_info(&nmea_present_enabled_healthy);
mavlink_log_info(mavlink_fd, "[gps] NMEA module found, status ok\n");
nmea_healthy = true;
nmea_fail_count = 0;
once_ok = true;
}
}
usleep(NMEA_WATCHDOG_WAIT_TIME_MICROSECONDS);
}
close(mavlink_fd);
return NULL;
}