/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup GSPModule GPS Module
* @brief Process GPS information
* @{
*
* @file GPS.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief GPS module, handles GPS and NMEA stream
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
// ****************
#include <openpilot.h>
#include "gpspositionsensor.h"
#include "homelocation.h"
#include "gpstime.h"
#include "gpssatellites.h"
#include "gpsvelocitysensor.h"
#include "gpssettings.h"
#include "taskinfo.h"
#include "hwsettings.h"
#include "WorldMagModel.h"
#include "CoordinateConversions.h"
#include "GPS.h"
#include "NMEA.h"
#include "UBX.h"
// ****************
// Private functions
static void gpsTask(void *parameters);
static void updateSettings();
#ifdef PIOS_GPS_SETS_HOMELOCATION
static void setHomeLocation(GPSPositionSensorData *gpsData);
static float GravityAccel(float latitude, float longitude, float altitude);
#endif
// ****************
// Private constants
#define GPS_TIMEOUT_MS 500
#ifdef PIOS_GPS_SETS_HOMELOCATION
// Unfortunately need a good size stack for the WMM calculation
#define STACK_SIZE_BYTES 1024
#else
#if defined(PIOS_GPS_MINIMAL)
#define STACK_SIZE_BYTES 500
#else
#define STACK_SIZE_BYTES 650
#endif // PIOS_GPS_MINIMAL
#endif // PIOS_GPS_SETS_HOMELOCATION
#define TASK_PRIORITY (tskIDLE_PRIORITY + 1)
// ****************
// Private variables
static uint32_t gpsPort;
static bool gpsEnabled = false;
static xTaskHandle gpsTaskHandle;
static char *gps_rx_buffer;
static uint32_t timeOfLastCommandMs;
static uint32_t timeOfLastUpdateMs;
#if defined(PIOS_INCLUDE_GPS_NMEA_PARSER) || defined(PIOS_INCLUDE_GPS_UBX_PARSER)
static struct GPS_RX_STATS gpsRxStats;
#endif
// ****************
/**
* Initialise the gps module
* \return -1 if initialisation failed
* \return 0 on success
*/
int32_t GPSStart(void)
{
if (gpsEnabled) {
if (gpsPort) {
// Start gps task
xTaskCreate(gpsTask, (signed char *)"GPS", STACK_SIZE_BYTES / 4, NULL, TASK_PRIORITY, &gpsTaskHandle);
PIOS_TASK_MONITOR_RegisterTask(TASKINFO_RUNNING_GPS, gpsTaskHandle);
return 0;
}
}
return -1;
}
/**
* Initialise the gps module
* \return -1 if initialisation failed
* \return 0 on success
*/
int32_t GPSInitialize(void)
{
gpsPort = PIOS_COM_GPS;
uint8_t gpsProtocol;
#ifdef MODULE_GPS_BUILTIN
gpsEnabled = true;
#else
HwSettingsInitialize();
HwSettingsOptionalModulesData optionalModules;
HwSettingsOptionalModulesGet(&optionalModules);
if (optionalModules.GPS == HWSETTINGS_OPTIONALMODULES_ENABLED) {
gpsEnabled = true;
} else {
gpsEnabled = false;
}
#endif
#if defined(REVOLUTION)
// These objects MUST be initialized for Revolution
// because the rest of the system expects to just
// attach to their queues
GPSPositionSensorInitialize();
GPSVelocitySensorInitialize();
GPSTimeInitialize();
GPSSatellitesInitialize();
HomeLocationInitialize();
updateSettings();
#else
if (gpsPort && gpsEnabled) {
GPSPositionSensorInitialize();
GPSVelocitySensorInitialize();
#if !defined(PIOS_GPS_MINIMAL)
GPSTimeInitialize();
GPSSatellitesInitialize();
#endif
#if defined(PIOS_GPS_SETS_HOMELOCATION)
HomeLocationInitialize();
#endif
updateSettings();
}
#endif /* if defined(REVOLUTION) */
if (gpsPort && gpsEnabled) {
GPSSettingsInitialize();
GPSSettingsDataProtocolGet(&gpsProtocol);
switch (gpsProtocol) {
case GPSSETTINGS_DATAPROTOCOL_NMEA:
gps_rx_buffer = pvPortMalloc(NMEA_MAX_PACKET_LENGTH);
break;
case GPSSETTINGS_DATAPROTOCOL_UBX:
gps_rx_buffer = pvPortMalloc(sizeof(struct UBXPacket));
break;
default:
gps_rx_buffer = NULL;
}
PIOS_Assert(gps_rx_buffer);
return 0;
}
return -1;
}
MODULE_INITCALL(GPSInitialize, GPSStart);
// ****************
/**
* Main gps task. It does not return.
*/
static void gpsTask(__attribute__((unused)) void *parameters)
{
portTickType xDelay = 100 / portTICK_RATE_MS;
uint32_t timeNowMs = xTaskGetTickCount() * portTICK_RATE_MS;
GPSPositionSensorData gpspositionsensor;
GPSSettingsData gpsSettings;
GPSSettingsGet(&gpsSettings);
timeOfLastUpdateMs = timeNowMs;
timeOfLastCommandMs = timeNowMs;
GPSPositionSensorGet(&gpspositionsensor);
// Loop forever
while (1) {
uint8_t c;
// This blocks the task until there is something on the buffer
while (PIOS_COM_ReceiveBuffer(gpsPort, &c, 1, xDelay) > 0) {
int res;
switch (gpsSettings.DataProtocol) {
#if defined(PIOS_INCLUDE_GPS_NMEA_PARSER)
case GPSSETTINGS_DATAPROTOCOL_NMEA:
res = parse_nmea_stream(c, gps_rx_buffer, &gpspositionsensor, &gpsRxStats);
break;
#endif
#if defined(PIOS_INCLUDE_GPS_UBX_PARSER)
case GPSSETTINGS_DATAPROTOCOL_UBX:
res = parse_ubx_stream(c, gps_rx_buffer, &gpspositionsensor, &gpsRxStats);
break;
#endif
default:
res = NO_PARSER; // this should not happen
break;
}
if (res == PARSER_COMPLETE) {
timeNowMs = xTaskGetTickCount() * portTICK_RATE_MS;
timeOfLastUpdateMs = timeNowMs;
timeOfLastCommandMs = timeNowMs;
}
}
// Check for GPS timeout
timeNowMs = xTaskGetTickCount() * portTICK_RATE_MS;
if ((timeNowMs - timeOfLastUpdateMs) >= GPS_TIMEOUT_MS) {
// we have not received any valid GPS sentences for a while.
// either the GPS is not plugged in or a hardware problem or the GPS has locked up.
uint8_t status = GPSPOSITIONSENSOR_STATUS_NOGPS;
GPSPositionSensorStatusSet(&status);
AlarmsSet(SYSTEMALARMS_ALARM_GPS, SYSTEMALARMS_ALARM_ERROR);
} else {
// we appear to be receiving GPS sentences OK, we've had an update
// criteria for GPS-OK taken from this post...
// http://forums.openpilot.org/topic/1523-professors-insgps-in-svn/page__view__findpost__p__5220
if ((gpspositionsensor.PDOP < gpsSettings.MaxPDOP) && (gpspositionsensor.Satellites >= gpsSettings.MinSattelites) &&
(gpspositionsensor.Status == GPSPOSITIONSENSOR_STATUS_FIX3D) &&
(gpspositionsensor.Latitude != 0 || gpspositionsensor.Longitude != 0)) {
AlarmsClear(SYSTEMALARMS_ALARM_GPS);
#ifdef PIOS_GPS_SETS_HOMELOCATION
HomeLocationData home;
HomeLocationGet(&home);
if (home.Set == HOMELOCATION_SET_FALSE) {
setHomeLocation(&gpspositionsensor);
}
#endif
} else if ((gpspositionsensor.Status == GPSPOSITIONSENSOR_STATUS_FIX3D) &&
(gpspositionsensor.Latitude != 0 || gpspositionsensor.Longitude != 0)) {
AlarmsSet(SYSTEMALARMS_ALARM_GPS, SYSTEMALARMS_ALARM_WARNING);
} else {
AlarmsSet(SYSTEMALARMS_ALARM_GPS, SYSTEMALARMS_ALARM_CRITICAL);
}
}
}
}
#ifdef PIOS_GPS_SETS_HOMELOCATION
/*
* Estimate the acceleration due to gravity for a particular location in LLA
*/
static float GravityAccel(float latitude, __attribute__((unused)) float longitude, float altitude)
{
/* WGS84 gravity model. The effect of gravity over latitude is strong
* enough to change the estimated accelerometer bias in those apps. */
float sinsq = sinf(latitude);
sinsq *= sinsq;
/* Likewise, over the altitude range of a high-altitude balloon, the effect
* due to change in altitude can also affect the model. */
return 9.7803267714f * (1.0f + 0.00193185138639f * sinsq) / sqrtf(1.0f - 0.00669437999013f * sinsq)
- 3.086e-6f * altitude;
}
// ****************
static void setHomeLocation(GPSPositionSensorData *gpsData)
{
HomeLocationData home;
HomeLocationGet(&home);
GPSTimeData gps;
GPSTimeGet(&gps);
if (gps.Year >= 2000) {
/* Store LLA */
home.Latitude = gpsData->Latitude;
home.Longitude = gpsData->Longitude;
home.Altitude = gpsData->Altitude + gpsData->GeoidSeparation;
/* Compute home ECEF coordinates and the rotation matrix into NED
* Note that floats are used here - they should give enough precision
* for this application.*/
float LLA[3] = { (home.Latitude) / 10e6f, (home.Longitude) / 10e6f, (home.Altitude) };
/* Compute magnetic flux direction at home location */
if (WMM_GetMagVector(LLA[0], LLA[1], LLA[2], gps.Month, gps.Day, gps.Year, &home.Be[0]) == 0) {
/*Compute local acceleration due to gravity. Vehicles that span a very large
* range of altitude (say, weather balloons) may need to update this during the
* flight. */
home.g_e = GravityAccel(LLA[0], LLA[1], LLA[2]);
home.Set = HOMELOCATION_SET_TRUE;
HomeLocationSet(&home);
}
}
}
#endif /* ifdef PIOS_GPS_SETS_HOMELOCATION */
/**
* Update the GPS settings, called on startup.
* FIXME: This should be in the GPSSettings object. But objects have
* too much overhead yet. Also the GPS has no any specific settings
* like protocol, etc. Thus the HwSettings object which contains the
* GPS port speed is used for now.
*/
static void updateSettings()
{
if (gpsPort) {
// Retrieve settings
uint8_t speed;
HwSettingsGPSSpeedGet(&speed);
// Set port speed
switch (speed) {
case HWSETTINGS_GPSSPEED_2400:
PIOS_COM_ChangeBaud(gpsPort, 2400);
break;
case HWSETTINGS_GPSSPEED_4800:
PIOS_COM_ChangeBaud(gpsPort, 4800);
break;
case HWSETTINGS_GPSSPEED_9600:
PIOS_COM_ChangeBaud(gpsPort, 9600);
break;
case HWSETTINGS_GPSSPEED_19200:
PIOS_COM_ChangeBaud(gpsPort, 19200);
break;
case HWSETTINGS_GPSSPEED_38400:
PIOS_COM_ChangeBaud(gpsPort, 38400);
break;
case HWSETTINGS_GPSSPEED_57600:
PIOS_COM_ChangeBaud(gpsPort, 57600);
break;
case HWSETTINGS_GPSSPEED_115200:
PIOS_COM_ChangeBaud(gpsPort, 115200);
break;
}
}
}
/**
* @}
* @}
*/