1,142 → 1,306 |
#include <inttypes.h> |
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#include "ubx.h" |
#include <avr/io.h> |
#include "timer0.h" |
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// ubx protocol parser state machine |
#define UBXSTATE_IDLE 0 |
#define UBXSTATE_SYNC1 1 |
#define UBXSTATE_SYNC2 2 |
#define UBXSTATE_CLASS 3 |
#define UBXSTATE_LEN1 4 |
#define UBXSTATE_LEN2 5 |
#define UBXSTATE_DATA 6 |
#define UBXSTATE_CKA 7 |
#define UBXSTATE_CKB 8 |
// ------------------------------------------------------------------------------------------------ |
// defines |
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// ublox protocoll identifier |
#define DAYS_FROM_JAN01YEAR0001_TO_JAN6_1980 722819 // the year 0 does not exist! |
#define DAYS_PER_YEAR 365 |
#define DAYS_PER_LEAPYEAR 366 |
#define DAYS_PER_4YEARS 1461 //((3 * DAYS_PER_YEAR) + DAYS_PER_LEAPYEAR) // years dividable by 4 are leap years |
#define DAYS_PER_100YEARS 36524 //((25 * DAYS_PER_4YEARS) - 1) // years dividable by 100 are no leap years |
#define DAYS_PER_400YEARS 146097 //((4 * DAYS_PER_100YEARS) + 1L) // but years dividable by 400 are leap years |
#define SECONDS_PER_MINUTE 60 |
#define MINUTES_PER_HOUR 60 |
#define HOURS_PER_DAY 24 |
#define DAYS_PER_WEEK 7 |
#define SECONDS_PER_HOUR 3600 //(SECONDS_PER_MINUTE * MINUTES_PER_HOUR) |
#define SECONDS_PER_DAY 86400 //(SECONDS_PER_HOUR * HOURS_PER_DAY) |
#define SECONDS_PER_WEEK 604800 //(SECONDS_PER_DAY * DAYS_PER_WEEK) |
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// days per month in normal and leap years |
const uint32_t Leap[ 13 ] = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }; |
const uint32_t Normal[ 13 ] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }; |
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#define LEAP_SECONDS_FROM_1980 15 // the last one was on the Dec 31th 2008 |
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// message sync bytes |
#define UBX_SYNC1_CHAR 0xB5 |
#define UBX_SYNC2_CHAR 0x62 |
// protocoll identifier |
#define UBX_CLASS_NAV 0x01 |
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// message id |
#define UBX_ID_POSLLH 0x02 |
#define UBX_ID_SOL 0x06 |
#define UBX_ID_VELNED 0x12 |
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#define UBX_SYNC1_CHAR 0xB5 |
#define UBX_SYNC2_CHAR 0x62 |
// ------------------------------------------------------------------------------------------------ |
// typedefs |
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typedef struct { |
uint32_t ITOW; // ms GPS Millisecond Time of Week |
int32_t Frac; // ns remainder of rounded ms above |
int16_t week; // GPS week |
uint8_t GPSfix; // GPSfix Type, range 0..6 |
uint8_t Flags; // Navigation Status Flags |
int32_t ECEF_X; // cm ECEF X coordinate |
int32_t ECEF_Y; // cm ECEF Y coordinate |
int32_t ECEF_Z; // cm ECEF Z coordinate |
uint32_t PAcc; // cm 3D Position Accuracy Estimate |
int32_t ECEFVX; // cm/s ECEF X velocity |
int32_t ECEFVY; // cm/s ECEF Y velocity |
int32_t ECEFVZ; // cm/s ECEF Z velocity |
uint32_t SAcc; // cm/s Speed Accuracy Estimate |
uint16_t PDOP; // 0.01 Position DOP |
uint8_t res1; // reserved |
uint8_t numSV; // Number of SVs used in navigation solution |
uint32_t res2; // reserved |
Status_t Status; |
} UBX_SOL_t; |
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typedef struct { |
uint32_t ITOW; // ms GPS Millisecond Time of Week |
int32_t LON; // 1e-07 deg Longitude |
int32_t LAT; // 1e-07 deg Latitude |
int32_t HEIGHT; // mm Height above Ellipsoid |
int32_t HMSL; // mm Height above mean sea level |
uint32_t Hacc; // mm Horizontal Accuracy Estimate |
uint32_t Vacc; // mm Vertical Accuracy Estimate |
Status_t Status; |
} UBX_POSLLH_t; |
// ubx parser state |
typedef enum |
{ |
UBXSTATE_IDLE, |
UBXSTATE_SYNC1, |
UBXSTATE_SYNC2, |
UBXSTATE_CLASS, |
UBXSTATE_LEN1, |
UBXSTATE_LEN2, |
UBXSTATE_DATA, |
UBXSTATE_CKA, |
UBXSTATE_CKB |
} ubxState_t; |
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typedef struct { |
uint32_t ITOW; // ms GPS Millisecond Time of Week |
int32_t VEL_N; // cm/s NED north velocity |
int32_t VEL_E; // cm/s NED east velocity |
int32_t VEL_D; // cm/s NED down velocity |
uint32_t Speed; // cm/s Speed (3-D) |
uint32_t GSpeed; // cm/s Ground Speed (2-D) |
int32_t Heading; // 1e-05 deg Heading 2-D |
uint32_t SAcc; // cm/s Speed Accuracy Estimate |
uint32_t CAcc; // deg Course / Heading Accuracy Estimate |
Status_t Status; |
} UBX_VELNED_t; |
typedef struct |
{ |
uint32_t itow; // ms GPS Millisecond Time of Week |
int32_t frac; // ns remainder of rounded ms above |
int16_t week; // GPS week |
uint8_t GPSfix; // GPSfix Type, range 0..6 |
uint8_t Flags; // Navigation Status Flags |
int32_t ECEF_X; // cm ECEF X coordinate |
int32_t ECEF_Y; // cm ECEF Y coordinate |
int32_t ECEF_Z; // cm ECEF Z coordinate |
int32_t PAcc; // cm 3D Position Accuracy Estimate |
int32_t ECEFVX; // cm/s ECEF X velocity |
int32_t ECEFVY; // cm/s ECEF Y velocity |
int32_t ECEFVZ; // cm/s ECEF Z velocity |
uint32_t SAcc; // cm/s Speed Accuracy Estimate |
uint16_t PDOP; // 0.01 Position DOP |
uint8_t res1; // reserved |
uint8_t numSV; // Number of SVs used in navigation solution |
uint32_t res2; // reserved |
uint8_t Status; // invalid/newdata/processed |
} __attribute__((packed)) ubx_nav_sol_t; |
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UBX_SOL_t UbxSol = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, INVALID}; |
UBX_POSLLH_t UbxPosLlh = {0,0,0,0,0,0,0, INVALID}; |
UBX_VELNED_t UbxVelNed = {0,0,0,0,0,0,0,0,0, INVALID}; |
GPS_INFO_t GPSInfo = {0,0,0,0,0,0,0,0,0,0, INVALID}; |
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volatile uint8_t GPSTimeout = 0; |
typedef struct |
{ |
uint32_t itow; // ms GPS Millisecond Time of Week |
int32_t VEL_N; // cm/s NED north velocity |
int32_t VEL_E; // cm/s NED east velocity |
int32_t VEL_D; // cm/s NED down velocity |
int32_t Speed; // cm/s Speed (3-D) |
int32_t GSpeed; // cm/s Ground Speed (2-D) |
int32_t Heading; // 1e-05 deg Heading 2-D |
uint32_t SAcc; // cm/s Speed Accuracy Estimate |
uint32_t CAcc; // deg Course / Heading Accuracy Estimate |
uint8_t Status; // invalid/newdata/processed |
} __attribute__((packed)) ubx_nav_velned_t; |
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void UpdateGPSInfo (void) |
typedef struct |
{ |
uint32_t itow; // ms GPS Millisecond Time of Week |
int32_t LON; // 1e-07 deg Longitude |
int32_t LAT; // 1e-07 deg Latitude |
int32_t HEIGHT; // mm Height above Ellipsoid |
int32_t HMSL; // mm Height above mean sea level |
uint32_t Hacc; // mm Horizontal Accuracy Estimate |
uint32_t Vacc; // mm Vertical Accuracy Estimate |
uint8_t Status; // invalid/newdata/processed |
} __attribute__((packed)) ubx_nav_posllh_t; |
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if ((UbxSol.Status == NEWDATA) && (UbxPosLlh.Status == NEWDATA) && (UbxVelNed.Status == NEWDATA)) |
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//------------------------------------------------------------------------------------ |
// global variables |
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// local buffers for the incomming ubx messages |
volatile ubx_nav_sol_t UbxSol = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, INVALID}; |
volatile ubx_nav_posllh_t UbxPosLlh = {0,0,0,0,0,0,0, INVALID}; |
volatile ubx_nav_velned_t UbxVelNed = {0,0,0,0,0,0,0,0,0, INVALID}; |
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uint16_t CheckGPSOkay = 0; |
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// shared buffer |
gps_data_t GPSData = {{0,0,0,INVALID},0,0,0,0,0,0,0, INVALID}; |
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//------------------------------------------------------------------------------------ |
// functions |
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uint8_t IsLeapYear(uint16_t year) |
{ |
if((year%400 == 0) || ( (year%4 == 0) && (year%100 != 0) ) ) return 1; |
else return 0; |
} |
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/********************************************************/ |
/* Calculates the UTC Time from the GPS week and tow */ |
/********************************************************/ |
void SetGPSTime(DateTime_t * pTimeStruct) |
{ |
uint32_t Days, Seconds, Week; |
uint16_t YearPart; |
uint32_t * MonthDayTab = 0; |
uint8_t i; |
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// if GPS data show valid time data |
if((UbxSol.Status != INVALID) && (UbxSol.Flags & FLAG_WKNSET) && (UbxSol.Flags & FLAG_TOWSET) ) |
{ |
if(GPSInfo.status != NEWDATA) |
Seconds = UbxSol.itow / 1000L; |
Week = (uint32_t)UbxSol.week; |
// correct leap seconds since 1980 |
if(Seconds < LEAP_SECONDS_FROM_1980) |
{ |
GPSInfo.status = INVALID; |
// NAV SOL |
GPSInfo.flags = UbxSol.Flags; |
GPSInfo.satfix = UbxSol.GPSfix; |
GPSInfo.satnum = UbxSol.numSV; |
GPSInfo.PAcc = UbxSol.PAcc; |
GPSInfo.VAcc = UbxSol.SAcc; |
// NAV POSLLH |
GPSInfo.longitude = UbxPosLlh.LON; |
GPSInfo.latitude = UbxPosLlh.LAT; |
GPSInfo.altitude = UbxPosLlh.HEIGHT; |
Week--; |
Seconds = SECONDS_PER_WEEK - LEAP_SECONDS_FROM_1980 + Seconds; |
} |
else Seconds -= LEAP_SECONDS_FROM_1980; |
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GPSInfo.veleast = UbxVelNed.VEL_E; |
GPSInfo.velnorth = UbxVelNed.VEL_N; |
GPSInfo.veltop = -UbxVelNed.VEL_D; |
GPSInfo.velground = UbxVelNed.GSpeed; |
Days = DAYS_FROM_JAN01YEAR0001_TO_JAN6_1980; |
Days += (Week * DAYS_PER_WEEK); |
Days += Seconds / SECONDS_PER_DAY; // seperate days from GPS seconds of week |
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GPSInfo.status = NEWDATA; |
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pTimeStruct->Year = 1; |
YearPart = (uint16_t)(Days / DAYS_PER_400YEARS); |
pTimeStruct->Year += YearPart * 400; |
Days = Days % DAYS_PER_400YEARS; |
YearPart = (uint16_t)(Days / DAYS_PER_100YEARS); |
pTimeStruct->Year += YearPart * 100; |
Days = Days % DAYS_PER_100YEARS; |
YearPart = (uint16_t)(Days / DAYS_PER_4YEARS); |
pTimeStruct->Year += YearPart * 4; |
Days = Days % DAYS_PER_4YEARS; |
if(Days < (3* DAYS_PER_YEAR)) YearPart = (uint16_t)(Days / DAYS_PER_YEAR); |
else YearPart = 3; |
pTimeStruct->Year += YearPart; |
// calculate remaining days of year |
Days -= (uint32_t)(YearPart * DAYS_PER_YEAR); |
Days += 1; |
// check if current year is a leap year |
if(IsLeapYear(pTimeStruct->Year)) MonthDayTab = (uint32_t*)Leap; |
else MonthDayTab = (uint32_t*)Normal; |
// seperate month and day from days of year |
for ( i = 0; i < 12; i++ ) |
{ |
if ( (MonthDayTab[i]< Days) && (Days <= MonthDayTab[i+1]) ) |
{ |
pTimeStruct->Month = i+1; |
pTimeStruct->Day = Days - MonthDayTab[i]; |
i = 12; |
} |
} |
// set state to collect new data |
UbxSol.Status = PROCESSED; // never update old data |
UbxPosLlh.Status = PROCESSED; // never update old data |
UbxVelNed.Status = PROCESSED; // never update old data |
Seconds = Seconds % SECONDS_PER_DAY; // remaining seconds of current day |
pTimeStruct->Hour = (uint8_t)(Seconds / SECONDS_PER_HOUR); |
Seconds = Seconds % SECONDS_PER_HOUR; // remaining seconds of current hour |
pTimeStruct->Min = (uint8_t)(Seconds / SECONDS_PER_MINUTE); |
Seconds = Seconds % SECONDS_PER_MINUTE; // remaining seconds of current minute |
pTimeStruct->Sec = (uint8_t)(Seconds); |
pTimeStruct->mSec = (uint16_t)(UbxSol.itow % 1000L); |
pTimeStruct->Valid = 1; |
} |
else |
{ |
pTimeStruct->Valid = 0; |
} |
} |
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/********************************************************/ |
/* Initialize UBX Parser */ |
/********************************************************/ |
void UBX_Init(void) |
{ |
// mark msg buffers invalid |
UbxSol.Status = INVALID; |
UbxPosLlh.Status = INVALID; |
UbxVelNed.Status = INVALID; |
GPSData.Status = INVALID; |
} |
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/********************************************************/ |
/* Upate GPS data stcructure */ |
/********************************************************/ |
void Update_GPSData (void) |
{ |
static uint16_t Ubx_Timeout = 0; |
static uint8_t Msg_Count = 0; |
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// this function should be called within the UART RX ISR |
void ubx_parser(uint8_t c) |
// the timeout is used to detect the delay between two message sets |
// and is used for synchronisation so that always a set is collected |
// that belongs together |
// _______NAVSOL|POSLLH|VELNED|___________________NAVSOL|POSLLH|VELNED|_____________ |
// | 8ms | 8ms | 184 ms | | | |
// msg_count: 0 1 2 0 1 2 |
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if(CheckDelay(Ubx_Timeout)) Msg_Count = 0; |
else Msg_Count++; |
Ubx_Timeout = SetDelay(100); // reset ubx msg timeout |
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// if a new set of ubx messages was collected |
if((Msg_Count >= 2)) |
{ // if set is complete |
if((UbxSol.Status == NEWDATA) && (UbxPosLlh.Status == NEWDATA) && (UbxVelNed.Status == NEWDATA)) |
{ |
CheckGPSOkay++; |
// update GPS data only if the status is INVALID or PROCESSED and the last ubx message was received within less than 100 ms |
if(GPSData.Status != NEWDATA) // if last data were processed |
{ // wait for new data at all neccesary ubx messages |
GPSData.Status = INVALID; |
// NAV SOL |
GPSData.Flags = UbxSol.Flags; |
GPSData.NumOfSats = UbxSol.numSV; |
GPSData.SatFix = UbxSol.GPSfix; |
GPSData.Position_Accuracy = UbxSol.PAcc; |
GPSData.Speed_Accuracy = UbxSol.SAcc; |
SetGPSTime(&SystemTime); // update system time |
// NAV POSLLH |
GPSData.Position.Status = INVALID; |
GPSData.Position.Longitude = UbxPosLlh.LON; |
GPSData.Position.Latitude = UbxPosLlh.LAT; |
GPSData.Position.Altitude = UbxPosLlh.HMSL; |
GPSData.Position.Status = NEWDATA; |
// NAV VELNED |
GPSData.Speed_East = UbxVelNed.VEL_E; |
GPSData.Speed_North = UbxVelNed.VEL_N; |
GPSData.Speed_Top = -UbxVelNed.VEL_D; |
GPSData.Speed_Ground = UbxVelNed.GSpeed; |
GPSData.Heading = UbxVelNed.Heading; |
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GPSData.Status = NEWDATA; // new data available |
} // EOF if(GPSData.Status != NEWDATA) |
} // EOF all ubx messages received |
// set state to collect new data |
UbxSol.Status = PROCESSED; // ready for new data |
UbxPosLlh.Status = PROCESSED; // ready for new data |
UbxVelNed.Status = PROCESSED; // ready for new data |
} |
} |
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/********************************************************/ |
/* UBX Parser */ |
/********************************************************/ |
void UBX_Parser(uint8_t c) |
{ |
static uint8_t ubxstate = UBXSTATE_IDLE; |
static ubxState_t ubxState = UBXSTATE_IDLE; |
static uint16_t msglen; |
static uint8_t cka, ckb; |
static uint16_t msglen; |
static int8_t *ubxP, *ubxEp, *ubxSp; // pointers to data currently transfered |
static uint8_t *ubxP, *ubxEp, *ubxSp; // pointers to data currently transfered |
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switch(ubxstate) |
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//state machine |
switch (ubxState) // ubx message parser |
{ |
case UBXSTATE_IDLE: // check 1st sync byte |
if (c == UBX_SYNC1_CHAR) ubxstate = UBXSTATE_SYNC1; |
else ubxstate = UBXSTATE_IDLE; // out of synchronization |
if (c == UBX_SYNC1_CHAR) ubxState = UBXSTATE_SYNC1; |
else ubxState = UBXSTATE_IDLE; // out of synchronization |
break; |
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case UBXSTATE_SYNC1: // check 2nd sync byte |
if (c == UBX_SYNC2_CHAR) ubxstate = UBXSTATE_SYNC2; |
else ubxstate = UBXSTATE_IDLE; // out of synchronization |
if (c == UBX_SYNC2_CHAR) ubxState = UBXSTATE_SYNC2; |
else ubxState = UBXSTATE_IDLE; // out of synchronization |
break; |
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case UBXSTATE_SYNC2: // check msg class to be NAV |
if (c == UBX_CLASS_NAV) ubxstate = UBXSTATE_CLASS; |
else ubxstate = UBXSTATE_IDLE; // unsupported message class |
if (c == UBX_CLASS_NAV) ubxState = UBXSTATE_CLASS; |
else ubxState = UBXSTATE_IDLE; // unsupported message class |
break; |
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case UBXSTATE_CLASS: // check message identifier |
143,30 → 307,30 |
switch(c) |
{ |
case UBX_ID_POSLLH: // geodetic position |
ubxP = (int8_t *)&UbxPosLlh; // data start pointer |
ubxEp = (int8_t *)(&UbxPosLlh + 1); // data end pointer |
ubxSp = (int8_t *)&UbxPosLlh.Status; // status pointer |
ubxP = (uint8_t *)&UbxPosLlh; // data start pointer |
ubxEp = (uint8_t *)(&UbxPosLlh + 1); // data end pointer |
ubxSp = (uint8_t *)&UbxPosLlh.Status; // status pointer |
break; |
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case UBX_ID_SOL: // navigation solution |
ubxP = (int8_t *)&UbxSol; // data start pointer |
ubxEp = (int8_t *)(&UbxSol + 1); // data end pointer |
ubxSp = (int8_t *)&UbxSol.Status; // status pointer |
ubxP = (uint8_t *)&UbxSol; // data start pointer |
ubxEp = (uint8_t *)(&UbxSol + 1); // data end pointer |
ubxSp = (uint8_t *)&UbxSol.Status; // status pointer |
break; |
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case UBX_ID_VELNED: // velocity vector in tangent plane |
ubxP = (int8_t *)&UbxVelNed; // data start pointer |
ubxEp = (int8_t *)(&UbxVelNed + 1); // data end pointer |
ubxSp = (int8_t *)&UbxVelNed.Status; // status pointer |
ubxP = (uint8_t *)&UbxVelNed; // data start pointer |
ubxEp = (uint8_t *)(&UbxVelNed + 1); // data end pointer |
ubxSp = (uint8_t *)&UbxVelNed.Status; // status pointer |
break; |
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default: // unsupported identifier |
ubxstate = UBXSTATE_IDLE; |
ubxState = UBXSTATE_IDLE; |
break; |
} |
if (ubxstate != UBXSTATE_IDLE) |
if (ubxState != UBXSTATE_IDLE) |
{ |
ubxstate = UBXSTATE_LEN1; |
ubxState = UBXSTATE_LEN1; |
cka = UBX_CLASS_NAV + c; |
ckb = UBX_CLASS_NAV + cka; |
} |
173,14 → 337,14 |
break; |
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case UBXSTATE_LEN1: // 1st message length byte |
msglen = c; |
msglen = (uint16_t)c; // lowbyte first |
cka += c; |
ckb += cka; |
ubxstate = UBXSTATE_LEN2; |
ubxState = UBXSTATE_LEN2; |
break; |
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case UBXSTATE_LEN2: // 2nd message length byte |
msglen += ((uint16_t)c)<<8; |
msglen += ((uint16_t)c)<<8; // high byte last |
cka += c; |
ckb += cka; |
// if the old data are not processed so far then break parsing now |
187,29 → 351,36 |
// to avoid writing new data in ISR during reading by another function |
if ( *ubxSp == NEWDATA ) |
{ |
UpdateGPSInfo(); //update GPS info respectively |
ubxstate = UBXSTATE_IDLE; |
ubxState = UBXSTATE_IDLE; |
Update_GPSData(); //update GPS info respectively |
} |
else // data invalid or allready processd |
{ |
*ubxSp = INVALID; |
ubxstate = UBXSTATE_DATA; |
*ubxSp = INVALID; // mark invalid during buffer filling |
ubxState = UBXSTATE_DATA; |
} |
break; |
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case UBXSTATE_DATA: |
if (ubxP < ubxEp) *ubxP++ = c; // copy curent data byte if any space is left |
cka += c; |
ckb += cka; |
if (--msglen == 0) ubxstate = UBXSTATE_CKA; // switch to next state if all data was read |
case UBXSTATE_DATA: // collecting data |
if (ubxP < ubxEp) |
{ |
*ubxP++ = c; // copy curent data byte if any space is left |
cka += c; |
ckb += cka; |
if (--msglen == 0) ubxState = UBXSTATE_CKA; // switch to next state if all data was read |
} |
else // rx buffer overrun |
{ |
ubxState = UBXSTATE_IDLE; |
} |
break; |
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case UBXSTATE_CKA: |
if (c == cka) ubxstate = UBXSTATE_CKB; |
if (c == cka) ubxState = UBXSTATE_CKB; |
else |
{ |
*ubxSp = INVALID; |
ubxstate = UBXSTATE_IDLE; |
ubxState = UBXSTATE_IDLE; |
} |
break; |
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217,21 → 388,18 |
if (c == ckb) |
{ |
*ubxSp = NEWDATA; // new data are valid |
UpdateGPSInfo(); //update GPS info respectively |
GPSTimeout = 255; |
Update_GPSData(); //update GPS info respectively |
} |
else |
{ // if checksum not fit then set data invalid |
{ // if checksum not match then set data invalid |
*ubxSp = INVALID; |
} |
ubxstate = UBXSTATE_IDLE; // ready to parse new data |
ubxState = UBXSTATE_IDLE; // ready to parse new data |
break; |
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default: // unknown ubx state |
ubxstate = UBXSTATE_IDLE; |
ubxState = UBXSTATE_IDLE; |
break; |
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} |
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} |
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