ardupilot/libraries/AP_GPS/GPS.cpp

287 lines
6.9 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#include <AP_Common.h>
#include <AP_Math.h>
#include <AP_HAL.h>
#include <AP_Notify.h>
#include "GPS.h"
extern const AP_HAL::HAL& hal;
#define GPS_DEBUGGING 0
#if GPS_DEBUGGING
# define Debug(fmt, args ...) do {hal.console->printf("%s:%d: " fmt "\n", __FUNCTION__, __LINE__, ## args); hal.scheduler->delay(0); } while(0)
#else
# define Debug(fmt, args ...)
#endif
GPS::GPS(void) :
// ensure all the inherited fields are zeroed
time_week_ms(0),
time_week(0),
latitude(0),
longitude(0),
altitude_cm(0),
ground_speed_cm(0),
ground_course_cd(0),
speed_3d_cm(0),
hdop(0),
num_sats(0),
new_data(false),
fix(FIX_NONE),
valid_read(false),
last_fix_time(0),
_have_raw_velocity(false),
_last_gps_time(0),
_idleTimer(0),
_status(GPS::NO_FIX),
_last_ground_speed_cm(0),
_velocity_north(0),
_velocity_east(0),
_velocity_down(0)
{
}
void
GPS::update(void)
{
bool result;
uint32_t tnow;
// call the GPS driver to process incoming data
result = read();
tnow = hal.scheduler->millis();
// if we did not get a message, and the idle timer of 1.2 seconds has expired, re-init
if (!result) {
if ((tnow - _idleTimer) > 1200) {
Debug("gps read timeout %lu %lu", (unsigned long)tnow, (unsigned long)_idleTimer);
_status = NO_GPS;
init(_port, _nav_setting);
// reset the idle timer
_idleTimer = tnow;
}
} else {
// we got a message, update our status correspondingly
if (fix == FIX_3D) {
_status = GPS_OK_FIX_3D;
}else if (fix == FIX_2D) {
_status = GPS_OK_FIX_2D;
}else{
_status = NO_FIX;
}
valid_read = true;
new_data = true;
// reset the idle timer
_idleTimer = tnow;
if (_status >= GPS_OK_FIX_2D) {
last_fix_time = _idleTimer;
_last_ground_speed_cm = ground_speed_cm;
if (_have_raw_velocity) {
// the GPS is able to give us velocity numbers directly
_velocity_north = _vel_north * 0.01f;
_velocity_east = _vel_east * 0.01f;
_velocity_down = _vel_down * 0.01f;
} else {
float gps_heading = ToRad(ground_course_cd * 0.01f);
float gps_speed = ground_speed_cm * 0.01f;
float sin_heading, cos_heading;
cos_heading = cosf(gps_heading);
sin_heading = sinf(gps_heading);
_velocity_north = gps_speed * cos_heading;
_velocity_east = gps_speed * sin_heading;
// no good way to get descent rate
_velocity_down = 0;
}
}
}
// update notify with gps status
AP_Notify::flags.gps_status = _status;
}
void
GPS::setHIL(uint64_t _time_epoch_ms, float _latitude, float _longitude, float _altitude,
float _ground_speed, float _ground_course, float _speed_3d, uint8_t _num_sats)
{
}
// XXX this is probably the wrong way to do it, too
void
GPS::_error(const char *msg)
{
hal.console->println(msg);
}
///
/// write a block of configuration data to a GPS
///
void GPS::_write_progstr_block(AP_HAL::UARTDriver *_fs, const prog_char *pstr, uint8_t size)
{
while (size--) {
_fs->write(pgm_read_byte(pstr++));
}
}
/*
a prog_char block queue, used to send out config commands to a GPS
in 16 byte chunks. This saves us having to have a 128 byte GPS send
buffer, while allowing us to avoid a long delay in sending GPS init
strings while waiting for the GPS auto detection to happen
*/
// maximum number of pending progstrings
#define PROGSTR_QUEUE_SIZE 3
struct progstr_queue {
const prog_char *pstr;
uint8_t ofs, size;
};
static struct {
AP_HAL::UARTDriver *fs;
uint8_t queue_size;
uint8_t idx, next_idx;
struct progstr_queue queue[PROGSTR_QUEUE_SIZE];
} progstr_state;
void GPS::_send_progstr(AP_HAL::UARTDriver *_fs, const prog_char *pstr, uint8_t size)
{
progstr_state.fs = _fs;
struct progstr_queue *q = &progstr_state.queue[progstr_state.next_idx];
q->pstr = pstr;
q->size = size;
q->ofs = 0;
progstr_state.next_idx++;
if (progstr_state.next_idx == PROGSTR_QUEUE_SIZE) {
progstr_state.next_idx = 0;
}
}
void GPS::_update_progstr(void)
{
struct progstr_queue *q = &progstr_state.queue[progstr_state.idx];
// quick return if nothing to do
if (q->size == 0 || progstr_state.fs->tx_pending()) {
return;
}
uint8_t nbytes = q->size - q->ofs;
if (nbytes > 16) {
nbytes = 16;
}
//hal.console->printf_P(PSTR("writing %u bytes\n"), (unsigned)nbytes);
_write_progstr_block(progstr_state.fs, q->pstr+q->ofs, nbytes);
q->ofs += nbytes;
if (q->ofs == q->size) {
q->size = 0;
progstr_state.idx++;
if (progstr_state.idx == PROGSTR_QUEUE_SIZE) {
progstr_state.idx = 0;
}
}
}
int32_t GPS::_swapl(const void *bytes) const
{
const uint8_t *b = (const uint8_t *)bytes;
union {
int32_t v;
uint8_t b[4];
} u;
u.b[0] = b[3];
u.b[1] = b[2];
u.b[2] = b[1];
u.b[3] = b[0];
return(u.v);
}
int16_t GPS::_swapi(const void *bytes) const
{
const uint8_t *b = (const uint8_t *)bytes;
union {
int16_t v;
uint8_t b[2];
} u;
u.b[0] = b[1];
u.b[1] = b[0];
return(u.v);
}
/**
current time since the unix epoch in microseconds
This costs about 60 usec on AVR2560
*/
uint64_t GPS::time_epoch_usec(void)
{
if (_last_gps_time == 0) {
return 0;
}
const uint64_t ms_per_week = 7000ULL*86400ULL;
const uint64_t unix_offset = 17000ULL*86400ULL + 52*10*7000ULL*86400ULL - 15000ULL;
uint64_t fix_time_ms = unix_offset + time_week*ms_per_week + time_week_ms;
// add in the milliseconds since the last fix
return (fix_time_ms + (hal.scheduler->millis() - _last_gps_time)) * 1000ULL;
}
/**
fill in time_week_ms and time_week from BCD date and time components
assumes MTK19 millisecond form of bcd_time
This function takes about 340 usec on the AVR2560
*/
void GPS::_make_gps_time(uint32_t bcd_date, uint32_t bcd_milliseconds)
{
uint8_t year, mon, day, hour, min, sec;
uint16_t msec;
year = bcd_date % 100;
mon = (bcd_date / 100) % 100;
day = bcd_date / 10000;
msec = bcd_milliseconds % 1000;
uint32_t v = bcd_milliseconds;
msec = v % 1000; v /= 1000;
sec = v % 100; v /= 100;
min = v % 100; v /= 100;
hour = v % 100; v /= 100;
int8_t rmon = mon - 2;
if (0 >= rmon) {
rmon += 12;
year -= 1;
}
// get time in seconds since unix epoch
uint32_t ret = (year/4) - 15 + 367*rmon/12 + day;
ret += year*365 + 10501;
ret = ret*24 + hour;
ret = ret*60 + min;
ret = ret*60 + sec;
// convert to time since GPS epoch
ret -= 272764785UL;
// get GPS week and time
time_week = ret / (7*86400UL);
time_week_ms = (ret % (7*86400UL)) * 1000;
time_week_ms += msec;
}