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betaflight/src/main/io/gps.c
2016-09-04 18:48:58 +01:00

1100 lines
36 KiB
C
Executable file

/*
* This file is part of Cleanflight.
*
* Cleanflight 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.
*
* Cleanflight 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 Cleanflight. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdbool.h>
#include <stdint.h>
#include <ctype.h>
#include <string.h>
#include <math.h>
#include "platform.h"
#ifdef GPS
#include "build/build_config.h"
#include "build/debug.h"
#include "common/maths.h"
#include "common/axis.h"
#include "common/utils.h"
#include "drivers/system.h"
#include "drivers/serial.h"
#include "drivers/serial_uart.h"
#include "drivers/gpio.h"
#include "drivers/light_led.h"
#include "sensors/sensors.h"
#include "io/serial.h"
#include "io/display.h"
#include "io/gps.h"
#include "flight/gps_conversion.h"
#include "flight/pid.h"
#include "flight/navigation.h"
#include "config/config.h"
#include "config/feature.h"
#include "fc/runtime_config.h"
#define LOG_ERROR '?'
#define LOG_IGNORED '!'
#define LOG_SKIPPED '>'
#define LOG_NMEA_GGA 'g'
#define LOG_NMEA_RMC 'r'
#define LOG_UBLOX_SOL 'O'
#define LOG_UBLOX_STATUS 'S'
#define LOG_UBLOX_SVINFO 'I'
#define LOG_UBLOX_POSLLH 'P'
#define LOG_UBLOX_VELNED 'V'
#define GPS_SV_MAXSATS 16
char gpsPacketLog[GPS_PACKET_LOG_ENTRY_COUNT];
static char *gpsPacketLogChar = gpsPacketLog;
// **********************
// GPS
// **********************
int32_t GPS_coord[2]; // LAT/LON
uint8_t GPS_numSat;
uint16_t GPS_hdop = 9999; // Compute GPS quality signal
uint32_t GPS_packetCount = 0;
uint32_t GPS_svInfoReceivedCount = 0; // SV = Space Vehicle, counter increments each time SV info is received.
uint8_t GPS_update = 0; // it's a binary toggle to distinct a GPS position update
uint16_t GPS_altitude; // altitude in 0.1m
uint16_t GPS_speed; // speed in 0.1m/s
uint16_t GPS_ground_course = 0; // degrees * 10
uint8_t GPS_numCh; // Number of channels
uint8_t GPS_svinfo_chn[GPS_SV_MAXSATS]; // Channel number
uint8_t GPS_svinfo_svid[GPS_SV_MAXSATS]; // Satellite ID
uint8_t GPS_svinfo_quality[GPS_SV_MAXSATS]; // Bitfield Qualtity
uint8_t GPS_svinfo_cno[GPS_SV_MAXSATS]; // Carrier to Noise Ratio (Signal Strength)
static gpsConfig_t *gpsConfig;
// GPS timeout for wrong baud rate/disconnection/etc in milliseconds (default 2.5second)
#define GPS_TIMEOUT (2500)
// How many entries in gpsInitData array below
#define GPS_INIT_ENTRIES (GPS_BAUDRATE_MAX + 1)
#define GPS_BAUDRATE_CHANGE_DELAY (200)
static serialConfig_t *serialConfig;
static serialPort_t *gpsPort;
typedef struct gpsInitData_s {
uint8_t index;
uint8_t baudrateIndex; // see baudRate_e
const char *ubx;
const char *mtk;
} gpsInitData_t;
// NMEA will cycle through these until valid data is received
static const gpsInitData_t gpsInitData[] = {
{ GPS_BAUDRATE_115200, BAUD_115200, "$PUBX,41,1,0003,0001,115200,0*1E\r\n", "$PMTK251,115200*1F\r\n" },
{ GPS_BAUDRATE_57600, BAUD_57600, "$PUBX,41,1,0003,0001,57600,0*2D\r\n", "$PMTK251,57600*2C\r\n" },
{ GPS_BAUDRATE_38400, BAUD_38400, "$PUBX,41,1,0003,0001,38400,0*26\r\n", "$PMTK251,38400*27\r\n" },
{ GPS_BAUDRATE_19200, BAUD_19200, "$PUBX,41,1,0003,0001,19200,0*23\r\n", "$PMTK251,19200*22\r\n" },
// 9600 is not enough for 5Hz updates - leave for compatibility to dumb NMEA that only runs at this speed
{ GPS_BAUDRATE_9600, BAUD_9600, "$PUBX,41,1,0003,0001,9600,0*16\r\n", "" }
};
#define GPS_INIT_DATA_ENTRY_COUNT (sizeof(gpsInitData) / sizeof(gpsInitData[0]))
#define DEFAULT_BAUD_RATE_INDEX 0
static const uint8_t ubloxInit[] = {
0xB5, 0x62, 0x06, 0x24, 0x24, 0x00, 0xFF, 0xFF, 0x03, 0x03, 0x00, // CFG-NAV5 - Set engine settings
0x00, 0x00, 0x00, 0x10, 0x27, 0x00, 0x00, 0x05, 0x00, 0xFA, 0x00, // Collected by resetting a GPS unit to defaults. Changing mode to Pedistrian and
0xFA, 0x00, 0x64, 0x00, 0x2C, 0x01, 0x00, 0x3C, 0x00, 0x00, 0x00, // capturing the data from the U-Center binary console.
0x00, 0xC8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x17, 0xC2,
// DISABLE NMEA messages
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x05, 0x00, 0xFF, 0x19, // VGS: Course over ground and Ground speed
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x03, 0x00, 0xFD, 0x15, // GSV: GNSS Satellites in View
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x01, 0x00, 0xFB, 0x11, // GLL: Latitude and longitude, with time of position fix and status
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x00, 0x00, 0xFA, 0x0F, // GGA: Global positioning system fix data
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x02, 0x00, 0xFC, 0x13, // GSA: GNSS DOP and Active Satellites
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0xF0, 0x04, 0x00, 0xFE, 0x17, // RMC: Recommended Minimum data
// Enable UBLOX messages
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x02, 0x01, 0x0E, 0x47, // set POSLLH MSG rate
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x03, 0x01, 0x0F, 0x49, // set STATUS MSG rate
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x06, 0x01, 0x12, 0x4F, // set SOL MSG rate
//0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x30, 0x01, 0x3C, 0xA3, // set SVINFO MSG rate (every cycle - high bandwidth)
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x30, 0x05, 0x40, 0xA7, // set SVINFO MSG rate (evey 5 cycles - low bandwidth)
0xB5, 0x62, 0x06, 0x01, 0x03, 0x00, 0x01, 0x12, 0x01, 0x1E, 0x67, // set VELNED MSG rate
0xB5, 0x62, 0x06, 0x08, 0x06, 0x00, 0xC8, 0x00, 0x01, 0x00, 0x01, 0x00, 0xDE, 0x6A, // set rate to 5Hz (measurement period: 200ms, navigation rate: 1 cycle)
};
// UBlox 6 Protocol documentation - GPS.G6-SW-10018-F
// SBAS Configuration Settings Desciption, Page 4/210
// 31.21 CFG-SBAS (0x06 0x16), Page 142/210
// A.10 SBAS Configuration (UBX-CFG-SBAS), Page 198/210 - GPS.G6-SW-10018-F
#define UBLOX_SBAS_MESSAGE_LENGTH 16
typedef struct ubloxSbas_s {
sbasMode_e mode;
uint8_t message[UBLOX_SBAS_MESSAGE_LENGTH];
} ubloxSbas_t;
// Note: these must be defined in the same order is sbasMode_e since no lookup table is used.
static const ubloxSbas_t ubloxSbas[] = {
// NOTE this could be optimized to save a few bytes of flash space since the same prefix is used for each command.
{ SBAS_AUTO, { 0xB5, 0x62, 0x06, 0x16, 0x08, 0x00, 0x03, 0x07, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x31, 0xE5}},
{ SBAS_EGNOS, { 0xB5, 0x62, 0x06, 0x16, 0x08, 0x00, 0x03, 0x07, 0x03, 0x00, 0x51, 0x08, 0x00, 0x00, 0x8A, 0x41}},
{ SBAS_WAAS, { 0xB5, 0x62, 0x06, 0x16, 0x08, 0x00, 0x03, 0x07, 0x03, 0x00, 0x04, 0xE0, 0x04, 0x00, 0x19, 0x9D}},
{ SBAS_MSAS, { 0xB5, 0x62, 0x06, 0x16, 0x08, 0x00, 0x03, 0x07, 0x03, 0x00, 0x00, 0x02, 0x02, 0x00, 0x35, 0xEF}},
{ SBAS_GAGAN, { 0xB5, 0x62, 0x06, 0x16, 0x08, 0x00, 0x03, 0x07, 0x03, 0x00, 0x80, 0x01, 0x00, 0x00, 0xB2, 0xE8}}
};
typedef enum {
GPS_UNKNOWN,
GPS_INITIALIZING,
GPS_CHANGE_BAUD,
GPS_CONFIGURE,
GPS_RECEIVING_DATA,
GPS_LOST_COMMUNICATION,
} gpsState_e;
gpsData_t gpsData;
static void shiftPacketLog(void)
{
uint32_t i;
for (i = ARRAYLEN(gpsPacketLog) - 1; i > 0 ; i--) {
gpsPacketLog[i] = gpsPacketLog[i-1];
}
}
static void gpsNewData(uint16_t c);
static bool gpsNewFrameNMEA(char c);
static bool gpsNewFrameUBLOX(uint8_t data);
static void gpsSetState(gpsState_e state)
{
gpsData.state = state;
gpsData.state_position = 0;
gpsData.state_ts = millis();
gpsData.messageState = GPS_MESSAGE_STATE_IDLE;
}
void gpsInit(serialConfig_t *initialSerialConfig, gpsConfig_t *initialGpsConfig)
{
serialConfig = initialSerialConfig;
gpsData.baudrateIndex = 0;
gpsData.errors = 0;
gpsData.timeouts = 0;
memset(gpsPacketLog, 0x00, sizeof(gpsPacketLog));
gpsConfig = initialGpsConfig;
// init gpsData structure. if we're not actually enabled, don't bother doing anything else
gpsSetState(GPS_UNKNOWN);
gpsData.lastMessage = millis();
serialPortConfig_t *gpsPortConfig = findSerialPortConfig(FUNCTION_GPS);
if (!gpsPortConfig) {
featureClear(FEATURE_GPS);
return;
}
while (gpsInitData[gpsData.baudrateIndex].baudrateIndex != gpsPortConfig->gps_baudrateIndex) {
gpsData.baudrateIndex++;
if (gpsData.baudrateIndex >= GPS_INIT_DATA_ENTRY_COUNT) {
gpsData.baudrateIndex = DEFAULT_BAUD_RATE_INDEX;
break;
}
}
portMode_t mode = MODE_RXTX;
// only RX is needed for NMEA-style GPS
#if !defined(COLIBRI_RACE) || !defined(LUX_RACE)
if (gpsConfig->provider == GPS_NMEA)
mode &= ~MODE_TX;
#endif
// no callback - buffer will be consumed in gpsThread()
gpsPort = openSerialPort(gpsPortConfig->identifier, FUNCTION_GPS, NULL, gpsInitData[gpsData.baudrateIndex].baudrateIndex, mode, SERIAL_NOT_INVERTED);
if (!gpsPort) {
featureClear(FEATURE_GPS);
return;
}
// signal GPS "thread" to initialize when it gets to it
gpsSetState(GPS_INITIALIZING);
}
void gpsInitNmea(void)
{
#if defined(COLIBRI_RACE) || defined(LUX_RACE)
uint32_t now;
#endif
switch(gpsData.state) {
case GPS_INITIALIZING:
#if defined(COLIBRI_RACE) || defined(LUX_RACE)
now = millis();
if (now - gpsData.state_ts < 1000)
return;
gpsData.state_ts = now;
if (gpsData.state_position < 1) {
serialSetBaudRate(gpsPort, 4800);
gpsData.state_position++;
} else if (gpsData.state_position < 2) {
// print our FIXED init string for the baudrate we want to be at
serialPrint(gpsPort, "$PSRF100,1,115200,8,1,0*05\r\n");
gpsData.state_position++;
} else {
// we're now (hopefully) at the correct rate, next state will switch to it
gpsSetState(GPS_CHANGE_BAUD);
}
break;
#endif
case GPS_CHANGE_BAUD:
#if defined(COLIBRI_RACE) || defined(LUX_RACE)
now = millis();
if (now - gpsData.state_ts < 1000)
return;
gpsData.state_ts = now;
if (gpsData.state_position < 1) {
serialSetBaudRate(gpsPort, baudRates[gpsInitData[gpsData.baudrateIndex].baudrateIndex]);
gpsData.state_position++;
} else if (gpsData.state_position < 2) {
serialPrint(gpsPort, "$PSRF103,00,6,00,0*23\r\n");
gpsData.state_position++;
} else {
#else
serialSetBaudRate(gpsPort, baudRates[gpsInitData[gpsData.baudrateIndex].baudrateIndex]);
#endif
gpsSetState(GPS_RECEIVING_DATA);
#if defined(COLIBRI_RACE) || defined(LUX_RACE)
}
#endif
break;
}
}
void gpsInitUblox(void)
{
uint32_t now;
// UBX will run at the serial port's baudrate, it shouldn't be "autodetected". So here we force it to that rate
// Wait until GPS transmit buffer is empty
if (!isSerialTransmitBufferEmpty(gpsPort))
return;
switch (gpsData.state) {
case GPS_INITIALIZING:
now = millis();
if (now - gpsData.state_ts < GPS_BAUDRATE_CHANGE_DELAY)
return;
if (gpsData.state_position < GPS_INIT_ENTRIES) {
// try different speed to INIT
baudRate_e newBaudRateIndex = gpsInitData[gpsData.state_position].baudrateIndex;
gpsData.state_ts = now;
if (lookupBaudRateIndex(serialGetBaudRate(gpsPort)) != newBaudRateIndex) {
// change the rate if needed and wait a little
serialSetBaudRate(gpsPort, baudRates[newBaudRateIndex]);
return;
}
// print our FIXED init string for the baudrate we want to be at
serialPrint(gpsPort, gpsInitData[gpsData.baudrateIndex].ubx);
gpsData.state_position++;
} else {
// we're now (hopefully) at the correct rate, next state will switch to it
gpsSetState(GPS_CHANGE_BAUD);
}
break;
case GPS_CHANGE_BAUD:
serialSetBaudRate(gpsPort, baudRates[gpsInitData[gpsData.baudrateIndex].baudrateIndex]);
gpsSetState(GPS_CONFIGURE);
break;
case GPS_CONFIGURE:
// Either use specific config file for GPS or let dynamically upload config
if( gpsConfig->autoConfig == GPS_AUTOCONFIG_OFF ) {
gpsSetState(GPS_RECEIVING_DATA);
break;
}
if (gpsData.messageState == GPS_MESSAGE_STATE_IDLE) {
gpsData.messageState++;
}
if (gpsData.messageState == GPS_MESSAGE_STATE_INIT) {
if (gpsData.state_position < sizeof(ubloxInit)) {
serialWrite(gpsPort, ubloxInit[gpsData.state_position]);
gpsData.state_position++;
} else {
gpsData.state_position = 0;
gpsData.messageState++;
}
}
if (gpsData.messageState == GPS_MESSAGE_STATE_SBAS) {
if (gpsData.state_position < UBLOX_SBAS_MESSAGE_LENGTH) {
serialWrite(gpsPort, ubloxSbas[gpsConfig->sbasMode].message[gpsData.state_position]);
gpsData.state_position++;
} else {
gpsData.messageState++;
}
}
if (gpsData.messageState >= GPS_MESSAGE_STATE_ENTRY_COUNT) {
// ublox should be initialised, try receiving
gpsSetState(GPS_RECEIVING_DATA);
}
break;
}
}
void gpsInitHardware(void)
{
switch (gpsConfig->provider) {
case GPS_NMEA:
gpsInitNmea();
break;
case GPS_UBLOX:
gpsInitUblox();
break;
}
}
void gpsThread(void)
{
// read out available GPS bytes
if (gpsPort) {
while (serialRxBytesWaiting(gpsPort))
gpsNewData(serialRead(gpsPort));
}
switch (gpsData.state) {
case GPS_UNKNOWN:
break;
case GPS_INITIALIZING:
case GPS_CHANGE_BAUD:
case GPS_CONFIGURE:
gpsInitHardware();
break;
case GPS_LOST_COMMUNICATION:
gpsData.timeouts++;
if (gpsConfig->autoBaud) {
// try another rate
gpsData.baudrateIndex++;
gpsData.baudrateIndex %= GPS_INIT_ENTRIES;
}
gpsData.lastMessage = millis();
// TODO - move some / all of these into gpsData
GPS_numSat = 0;
DISABLE_STATE(GPS_FIX);
gpsSetState(GPS_INITIALIZING);
break;
case GPS_RECEIVING_DATA:
// check for no data/gps timeout/cable disconnection etc
if (millis() - gpsData.lastMessage > GPS_TIMEOUT) {
// remove GPS from capability
sensorsClear(SENSOR_GPS);
gpsSetState(GPS_LOST_COMMUNICATION);
}
break;
}
}
static void gpsNewData(uint16_t c)
{
if (!gpsNewFrame(c)) {
return;
}
// new data received and parsed, we're in business
gpsData.lastLastMessage = gpsData.lastMessage;
gpsData.lastMessage = millis();
sensorsSet(SENSOR_GPS);
if (GPS_update == 1)
GPS_update = 0;
else
GPS_update = 1;
#if 0
debug[3] = GPS_update;
#endif
onGpsNewData();
}
bool gpsNewFrame(uint8_t c)
{
switch (gpsConfig->provider) {
case GPS_NMEA: // NMEA
return gpsNewFrameNMEA(c);
case GPS_UBLOX: // UBX binary
return gpsNewFrameUBLOX(c);
}
return false;
}
/* This is a light implementation of a GPS frame decoding
This should work with most of modern GPS devices configured to output 5 frames.
It assumes there are some NMEA GGA frames to decode on the serial bus
Now verifies checksum correctly before applying data
Here we use only the following data :
- latitude
- longitude
- GPS fix is/is not ok
- GPS num sat (4 is enough to be +/- reliable)
// added by Mis
- GPS altitude (for OSD displaying)
- GPS speed (for OSD displaying)
*/
#define NO_FRAME 0
#define FRAME_GGA 1
#define FRAME_RMC 2
#define FRAME_GSV 3
// This code is used for parsing NMEA data
/* Alex optimization
The latitude or longitude is coded this way in NMEA frames
dm.f coded as degrees + minutes + minute decimal
Where:
- d can be 1 or more char long. generally: 2 char long for latitude, 3 char long for longitude
- m is always 2 char long
- f can be 1 or more char long
This function converts this format in a unique unsigned long where 1 degree = 10 000 000
EOS increased the precision here, even if we think that the gps is not precise enough, with 10e5 precision it has 76cm resolution
with 10e7 it's around 1 cm now. Increasing it further is irrelevant, since even 1cm resolution is unrealistic, however increased
resolution also increased precision of nav calculations
static uint32_t GPS_coord_to_degrees(char *coordinateString)
{
char *p = s, *d = s;
uint8_t min, deg = 0;
uint16_t frac = 0, mult = 10000;
while (*p) { // parse the string until its end
if (d != s) {
frac += (*p - '0') * mult; // calculate only fractional part on up to 5 digits (d != s condition is true when the . is located)
mult /= 10;
}
if (*p == '.')
d = p; // locate '.' char in the string
p++;
}
if (p == s)
return 0;
while (s < d - 2) {
deg *= 10; // convert degrees : all chars before minutes ; for the first iteration, deg = 0
deg += *(s++) - '0';
}
min = *(d - 1) - '0' + (*(d - 2) - '0') * 10; // convert minutes : 2 previous char before '.'
return deg * 10000000UL + (min * 100000UL + frac) * 10UL / 6;
}
*/
// helper functions
static uint32_t grab_fields(char *src, uint8_t mult)
{ // convert string to uint32
uint32_t i;
uint32_t tmp = 0;
for (i = 0; src[i] != 0; i++) {
if (src[i] == '.') {
i++;
if (mult == 0)
break;
else
src[i + mult] = 0;
}
tmp *= 10;
if (src[i] >= '0' && src[i] <= '9')
tmp += src[i] - '0';
if (i >= 15)
return 0; // out of bounds
}
return tmp;
}
typedef struct gpsDataNmea_s {
int32_t latitude;
int32_t longitude;
uint8_t numSat;
uint16_t altitude;
uint16_t speed;
uint16_t ground_course;
} gpsDataNmea_t;
static bool gpsNewFrameNMEA(char c)
{
static gpsDataNmea_t gps_Msg;
uint8_t frameOK = 0;
static uint8_t param = 0, offset = 0, parity = 0;
static char string[15];
static uint8_t checksum_param, gps_frame = NO_FRAME;
static uint8_t svMessageNum = 0;
uint8_t svSatNum = 0, svPacketIdx = 0, svSatParam = 0;
switch (c) {
case '$':
param = 0;
offset = 0;
parity = 0;
break;
case ',':
case '*':
string[offset] = 0;
if (param == 0) { //frame identification
gps_frame = NO_FRAME;
if (string[0] == 'G' && string[1] == 'P' && string[2] == 'G' && string[3] == 'G' && string[4] == 'A')
gps_frame = FRAME_GGA;
if (string[0] == 'G' && string[1] == 'P' && string[2] == 'R' && string[3] == 'M' && string[4] == 'C')
gps_frame = FRAME_RMC;
if (string[0] == 'G' && string[1] == 'P' && string[2] == 'G' && string[3] == 'S' && string[4] == 'V')
gps_frame = FRAME_GSV;
}
switch (gps_frame) {
case FRAME_GGA: //************* GPGGA FRAME parsing
switch(param) {
// case 1: // Time information
// break;
case 2:
gps_Msg.latitude = GPS_coord_to_degrees(string);
break;
case 3:
if (string[0] == 'S')
gps_Msg.latitude *= -1;
break;
case 4:
gps_Msg.longitude = GPS_coord_to_degrees(string);
break;
case 5:
if (string[0] == 'W')
gps_Msg.longitude *= -1;
break;
case 6:
if (string[0] > '0') {
ENABLE_STATE(GPS_FIX);
} else {
DISABLE_STATE(GPS_FIX);
}
break;
case 7:
gps_Msg.numSat = grab_fields(string, 0);
break;
case 9:
gps_Msg.altitude = grab_fields(string, 0); // altitude in meters added by Mis
break;
}
break;
case FRAME_RMC: //************* GPRMC FRAME parsing
switch(param) {
case 7:
gps_Msg.speed = ((grab_fields(string, 1) * 5144L) / 1000L); // speed in cm/s added by Mis
break;
case 8:
gps_Msg.ground_course = (grab_fields(string, 1)); // ground course deg * 10
break;
}
break;
case FRAME_GSV:
switch(param) {
/*case 1:
// Total number of messages of this type in this cycle
break; */
case 2:
// Message number
svMessageNum = grab_fields(string, 0);
break;
case 3:
// Total number of SVs visible
GPS_numCh = grab_fields(string, 0);
break;
}
if(param < 4)
break;
svPacketIdx = (param - 4) / 4 + 1; // satellite number in packet, 1-4
svSatNum = svPacketIdx + (4 * (svMessageNum - 1)); // global satellite number
svSatParam = param - 3 - (4 * (svPacketIdx - 1)); // parameter number for satellite
if(svSatNum > GPS_SV_MAXSATS)
break;
switch(svSatParam) {
case 1:
// SV PRN number
GPS_svinfo_chn[svSatNum - 1] = svSatNum;
GPS_svinfo_svid[svSatNum - 1] = grab_fields(string, 0);
break;
/*case 2:
// Elevation, in degrees, 90 maximum
break;
case 3:
// Azimuth, degrees from True North, 000 through 359
break; */
case 4:
// SNR, 00 through 99 dB (null when not tracking)
GPS_svinfo_cno[svSatNum - 1] = grab_fields(string, 0);
GPS_svinfo_quality[svSatNum - 1] = 0; // only used by ublox
break;
}
GPS_svInfoReceivedCount++;
break;
}
param++;
offset = 0;
if (c == '*')
checksum_param = 1;
else
parity ^= c;
break;
case '\r':
case '\n':
if (checksum_param) { //parity checksum
shiftPacketLog();
uint8_t checksum = 16 * ((string[0] >= 'A') ? string[0] - 'A' + 10 : string[0] - '0') + ((string[1] >= 'A') ? string[1] - 'A' + 10 : string[1] - '0');
if (checksum == parity) {
*gpsPacketLogChar = LOG_IGNORED;
GPS_packetCount++;
switch (gps_frame) {
case FRAME_GGA:
*gpsPacketLogChar = LOG_NMEA_GGA;
frameOK = 1;
if (STATE(GPS_FIX)) {
GPS_coord[LAT] = gps_Msg.latitude;
GPS_coord[LON] = gps_Msg.longitude;
GPS_numSat = gps_Msg.numSat;
GPS_altitude = gps_Msg.altitude;
}
break;
case FRAME_RMC:
*gpsPacketLogChar = LOG_NMEA_RMC;
GPS_speed = gps_Msg.speed;
GPS_ground_course = gps_Msg.ground_course;
break;
} // end switch
} else {
*gpsPacketLogChar = LOG_ERROR;
}
}
checksum_param = 0;
break;
default:
if (offset < 15)
string[offset++] = c;
if (!checksum_param)
parity ^= c;
}
return frameOK;
}
// UBX support
typedef struct {
uint8_t preamble1;
uint8_t preamble2;
uint8_t msg_class;
uint8_t msg_id;
uint16_t length;
} ubx_header;
typedef struct {
uint32_t time; // GPS msToW
int32_t longitude;
int32_t latitude;
int32_t altitude_ellipsoid;
int32_t altitude_msl;
uint32_t horizontal_accuracy;
uint32_t vertical_accuracy;
} ubx_nav_posllh;
typedef struct {
uint32_t time; // GPS msToW
uint8_t fix_type;
uint8_t fix_status;
uint8_t differential_status;
uint8_t res;
uint32_t time_to_first_fix;
uint32_t uptime; // milliseconds
} ubx_nav_status;
typedef struct {
uint32_t time;
int32_t time_nsec;
int16_t week;
uint8_t fix_type;
uint8_t fix_status;
int32_t ecef_x;
int32_t ecef_y;
int32_t ecef_z;
uint32_t position_accuracy_3d;
int32_t ecef_x_velocity;
int32_t ecef_y_velocity;
int32_t ecef_z_velocity;
uint32_t speed_accuracy;
uint16_t position_DOP;
uint8_t res;
uint8_t satellites;
uint32_t res2;
} ubx_nav_solution;
typedef struct {
uint32_t time; // GPS msToW
int32_t ned_north;
int32_t ned_east;
int32_t ned_down;
uint32_t speed_3d;
uint32_t speed_2d;
int32_t heading_2d;
uint32_t speed_accuracy;
uint32_t heading_accuracy;
} ubx_nav_velned;
typedef struct {
uint8_t chn; // Channel number, 255 for SVx not assigned to channel
uint8_t svid; // Satellite ID
uint8_t flags; // Bitmask
uint8_t quality; // Bitfield
uint8_t cno; // Carrier to Noise Ratio (Signal Strength) // dbHz, 0-55.
uint8_t elev; // Elevation in integer degrees
int16_t azim; // Azimuth in integer degrees
int32_t prRes; // Pseudo range residual in centimetres
} ubx_nav_svinfo_channel;
typedef struct {
uint32_t time; // GPS Millisecond time of week
uint8_t numCh; // Number of channels
uint8_t globalFlags; // Bitmask, Chip hardware generation 0:Antaris, 1:u-blox 5, 2:u-blox 6
uint16_t reserved2; // Reserved
ubx_nav_svinfo_channel channel[16]; // 16 satellites * 12 byte
} ubx_nav_svinfo;
enum {
PREAMBLE1 = 0xb5,
PREAMBLE2 = 0x62,
CLASS_NAV = 0x01,
CLASS_ACK = 0x05,
CLASS_CFG = 0x06,
MSG_ACK_NACK = 0x00,
MSG_ACK_ACK = 0x01,
MSG_POSLLH = 0x2,
MSG_STATUS = 0x3,
MSG_SOL = 0x6,
MSG_VELNED = 0x12,
MSG_SVINFO = 0x30,
MSG_CFG_PRT = 0x00,
MSG_CFG_RATE = 0x08,
MSG_CFG_SET_RATE = 0x01,
MSG_CFG_NAV_SETTINGS = 0x24
} ubx_protocol_bytes;
enum {
FIX_NONE = 0,
FIX_DEAD_RECKONING = 1,
FIX_2D = 2,
FIX_3D = 3,
FIX_GPS_DEAD_RECKONING = 4,
FIX_TIME = 5
} ubs_nav_fix_type;
enum {
NAV_STATUS_FIX_VALID = 1
} ubx_nav_status_bits;
// Packet checksum accumulators
static uint8_t _ck_a;
static uint8_t _ck_b;
// State machine state
static bool _skip_packet;
static uint8_t _step;
static uint8_t _msg_id;
static uint16_t _payload_length;
static uint16_t _payload_counter;
static bool next_fix;
static uint8_t _class;
// do we have new position information?
static bool _new_position;
// do we have new speed information?
static bool _new_speed;
// Example packet sizes from UBlox u-center from a Glonass capable GPS receiver.
//15:17:55 R -> UBX NAV-STATUS, Size 24, 'Navigation Status'
//15:17:55 R -> UBX NAV-POSLLH, Size 36, 'Geodetic Position'
//15:17:55 R -> UBX NAV-VELNED, Size 44, 'Velocity in WGS 84'
//15:17:55 R -> UBX NAV-CLOCK, Size 28, 'Clock Status'
//15:17:55 R -> UBX NAV-AOPSTATUS, Size 24, 'AOP Status'
//15:17:55 R -> UBX 03-09, Size 208, 'Unknown'
//15:17:55 R -> UBX 03-10, Size 336, 'Unknown'
//15:17:55 R -> UBX NAV-SOL, Size 60, 'Navigation Solution'
//15:17:55 R -> UBX NAV, Size 100, 'Navigation'
//15:17:55 R -> UBX NAV-SVINFO, Size 328, 'Satellite Status and Information'
// from the UBlox6 document, the largest payout we receive i the NAV-SVINFO and the payload size
// is calculated as 8 + 12*numCh. numCh in the case of a Glonass receiver is 28.
#define UBLOX_PAYLOAD_SIZE 344
// Receive buffer
static union {
ubx_nav_posllh posllh;
ubx_nav_status status;
ubx_nav_solution solution;
ubx_nav_velned velned;
ubx_nav_svinfo svinfo;
uint8_t bytes[UBLOX_PAYLOAD_SIZE];
} _buffer;
void _update_checksum(uint8_t *data, uint8_t len, uint8_t *ck_a, uint8_t *ck_b)
{
while (len--) {
*ck_a += *data;
*ck_b += *ck_a;
data++;
}
}
static bool UBLOX_parse_gps(void)
{
uint32_t i;
*gpsPacketLogChar = LOG_IGNORED;
switch (_msg_id) {
case MSG_POSLLH:
*gpsPacketLogChar = LOG_UBLOX_POSLLH;
//i2c_dataset.time = _buffer.posllh.time;
GPS_coord[LON] = _buffer.posllh.longitude;
GPS_coord[LAT] = _buffer.posllh.latitude;
GPS_altitude = _buffer.posllh.altitude_msl / 10 / 100; //alt in m
if (next_fix) {
ENABLE_STATE(GPS_FIX);
} else {
DISABLE_STATE(GPS_FIX);
}
_new_position = true;
break;
case MSG_STATUS:
*gpsPacketLogChar = LOG_UBLOX_STATUS;
next_fix = (_buffer.status.fix_status & NAV_STATUS_FIX_VALID) && (_buffer.status.fix_type == FIX_3D);
if (!next_fix)
DISABLE_STATE(GPS_FIX);
break;
case MSG_SOL:
*gpsPacketLogChar = LOG_UBLOX_SOL;
next_fix = (_buffer.solution.fix_status & NAV_STATUS_FIX_VALID) && (_buffer.solution.fix_type == FIX_3D);
if (!next_fix)
DISABLE_STATE(GPS_FIX);
GPS_numSat = _buffer.solution.satellites;
GPS_hdop = _buffer.solution.position_DOP;
break;
case MSG_VELNED:
*gpsPacketLogChar = LOG_UBLOX_VELNED;
// speed_3d = _buffer.velned.speed_3d; // cm/s
GPS_speed = _buffer.velned.speed_2d; // cm/s
GPS_ground_course = (uint16_t) (_buffer.velned.heading_2d / 10000); // Heading 2D deg * 100000 rescaled to deg * 10
_new_speed = true;
break;
case MSG_SVINFO:
*gpsPacketLogChar = LOG_UBLOX_SVINFO;
GPS_numCh = _buffer.svinfo.numCh;
if (GPS_numCh > 16)
GPS_numCh = 16;
for (i = 0; i < GPS_numCh; i++){
GPS_svinfo_chn[i]= _buffer.svinfo.channel[i].chn;
GPS_svinfo_svid[i]= _buffer.svinfo.channel[i].svid;
GPS_svinfo_quality[i]=_buffer.svinfo.channel[i].quality;
GPS_svinfo_cno[i]= _buffer.svinfo.channel[i].cno;
}
GPS_svInfoReceivedCount++;
break;
default:
return false;
}
// we only return true when we get new position and speed data
// this ensures we don't use stale data
if (_new_position && _new_speed) {
_new_speed = _new_position = false;
return true;
}
return false;
}
static bool gpsNewFrameUBLOX(uint8_t data)
{
bool parsed = false;
switch (_step) {
case 0: // Sync char 1 (0xB5)
if (PREAMBLE1 == data) {
_skip_packet = false;
_step++;
}
break;
case 1: // Sync char 2 (0x62)
if (PREAMBLE2 != data) {
_step = 0;
break;
}
_step++;
break;
case 2: // Class
_step++;
_class = data;
_ck_b = _ck_a = data; // reset the checksum accumulators
break;
case 3: // Id
_step++;
_ck_b += (_ck_a += data); // checksum byte
_msg_id = data;
break;
case 4: // Payload length (part 1)
_step++;
_ck_b += (_ck_a += data); // checksum byte
_payload_length = data; // payload length low byte
break;
case 5: // Payload length (part 2)
_step++;
_ck_b += (_ck_a += data); // checksum byte
_payload_length += (uint16_t)(data << 8);
if (_payload_length > UBLOX_PAYLOAD_SIZE) {
_skip_packet = true;
}
_payload_counter = 0; // prepare to receive payload
if (_payload_length == 0) {
_step = 7;
}
break;
case 6:
_ck_b += (_ck_a += data); // checksum byte
if (_payload_counter < UBLOX_PAYLOAD_SIZE) {
_buffer.bytes[_payload_counter] = data;
}
if (++_payload_counter >= _payload_length) {
_step++;
}
break;
case 7:
_step++;
if (_ck_a != data) {
_skip_packet = true; // bad checksum
gpsData.errors++;
}
break;
case 8:
_step = 0;
shiftPacketLog();
if (_ck_b != data) {
*gpsPacketLogChar = LOG_ERROR;
gpsData.errors++;
break; // bad checksum
}
GPS_packetCount++;
if (_skip_packet) {
*gpsPacketLogChar = LOG_SKIPPED;
break;
}
if (UBLOX_parse_gps()) {
parsed = true;
}
}
return parsed;
}
static void gpsHandlePassthrough(uint8_t data)
{
gpsNewData(data);
#ifdef DISPLAY
if (feature(FEATURE_DISPLAY)) {
updateDisplay();
}
#endif
}
void gpsEnablePassthrough(serialPort_t *gpsPassthroughPort)
{
waitForSerialPortToFinishTransmitting(gpsPort);
waitForSerialPortToFinishTransmitting(gpsPassthroughPort);
if(!(gpsPort->mode & MODE_TX))
serialSetMode(gpsPort, gpsPort->mode | MODE_TX);
#ifdef DISPLAY
if (feature(FEATURE_DISPLAY)) {
displayShowFixedPage(PAGE_GPS);
}
#endif
serialPassthrough(gpsPort, gpsPassthroughPort, &gpsHandlePassthrough, NULL);
}
void updateGpsIndicator(uint32_t currentTime)
{
static uint32_t GPSLEDTime;
if ((int32_t)(currentTime - GPSLEDTime) >= 0 && (GPS_numSat >= 5)) {
GPSLEDTime = currentTime + 150000;
LED1_TOGGLE;
}
}
#endif