WebSVN - Projects - Blame - Rev 436 - /FollowMe/trunk/ubx.c

Rev	Author	Line No.	Line
426	killagreg	1	#include <inttypes.h>
		2	#include "ubx.h"
		3	#include "timer0.h"
		4	#include "uart0.h"
436	killagreg	5	#include "printf_P.h"
426	killagreg	6
		7
		8	// ------------------------------------------------------------------------------------------------
		9	// defines
		10
		11	#define DAYS_FROM_JAN01YEAR0001_TO_JAN6_1980 722819 // the year 0 does not exist!
		12	#define DAYS_PER_YEAR 365
		13	#define DAYS_PER_LEAPYEAR 366
		14	#define DAYS_PER_4YEARS 1461 //((3 * DAYS_PER_YEAR) + DAYS_PER_LEAPYEAR) // years dividable by 4 are leap years
		15	#define DAYS_PER_100YEARS 36524 //((25 * DAYS_PER_4YEARS) - 1) // years dividable by 100 are no leap years
		16	#define DAYS_PER_400YEARS 146097 //((4 * DAYS_PER_100YEARS) + 1L) // but years dividable by 400 are leap years
		17	#define SECONDS_PER_MINUTE 60
		18	#define MINUTES_PER_HOUR 60
		19	#define HOURS_PER_DAY 24
		20	#define DAYS_PER_WEEK 7
		21	#define SECONDS_PER_HOUR 3600 //(SECONDS_PER_MINUTE * MINUTES_PER_HOUR)
		22	#define SECONDS_PER_DAY 86400 //(SECONDS_PER_HOUR * HOURS_PER_DAY)
		23	#define SECONDS_PER_WEEK 604800 //(SECONDS_PER_DAY * DAYS_PER_WEEK)
		24
		25	// days per month in normal and leap years
		26	const uint32_t Leap[ 13 ] = { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 };
		27	const uint32_t Normal[ 13 ] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
		28
		29	#define LEAP_SECONDS_FROM_1980 15 // the last one was on the Dec 31th 2008
		30
		31	// message sync bytes
		32	#define UBX_SYNC1_CHAR 0xB5
		33	#define UBX_SYNC2_CHAR 0x62
		34	// protocoll identifier
		35	#define UBX_CLASS_NAV 0x01
		36	// message id
		37	#define UBX_ID_POSLLH 0x02
		38	#define UBX_ID_SOL 0x06
		39	#define UBX_ID_VELNED 0x12
		40
		41	// ------------------------------------------------------------------------------------------------
		42	// typedefs
		43
		44
		45	// ubx parser state
		46	typedef enum
		47	{
		48	UBXSTATE_IDLE,
		49	UBXSTATE_SYNC1,
		50	UBXSTATE_SYNC2,
		51	UBXSTATE_CLASS,
		52	UBXSTATE_LEN1,
		53	UBXSTATE_LEN2,
		54	UBXSTATE_DATA,
		55	UBXSTATE_CKA,
		56	UBXSTATE_CKB
		57	} ubxState_t;
		58
		59	typedef struct
		60	{
		61	uint32_t itow; // ms GPS Millisecond Time of Week
		62	int32_t frac; // ns remainder of rounded ms above
		63	int16_t week; // GPS week
		64	uint8_t GPSfix; // GPSfix Type, range 0..6
		65	uint8_t Flags; // Navigation Status Flags
		66	int32_t ECEF_X; // cm ECEF X coordinate
		67	int32_t ECEF_Y; // cm ECEF Y coordinate
		68	int32_t ECEF_Z; // cm ECEF Z coordinate
		69	int32_t PAcc; // cm 3D Position Accuracy Estimate
		70	int32_t ECEFVX; // cm/s ECEF X velocity
		71	int32_t ECEFVY; // cm/s ECEF Y velocity
		72	int32_t ECEFVZ; // cm/s ECEF Z velocity
		73	uint32_t SAcc; // cm/s Speed Accuracy Estimate
		74	uint16_t PDOP; // 0.01 Position DOP
		75	uint8_t res1; // reserved
		76	uint8_t numSV; // Number of SVs used in navigation solution
		77	uint32_t res2; // reserved
		78	uint8_t Status; // invalid/newdata/processed
		79	} __attribute__((packed)) ubx_nav_sol_t;
		80
		81
		82	typedef struct
		83	{
		84	uint32_t itow; // ms GPS Millisecond Time of Week
		85	int32_t VEL_N; // cm/s NED north velocity
		86	int32_t VEL_E; // cm/s NED east velocity
		87	int32_t VEL_D; // cm/s NED down velocity
		88	int32_t Speed; // cm/s Speed (3-D)
		89	int32_t GSpeed; // cm/s Ground Speed (2-D)
		90	int32_t Heading; // 1e-05 deg Heading 2-D
		91	uint32_t SAcc; // cm/s Speed Accuracy Estimate
		92	uint32_t CAcc; // deg Course / Heading Accuracy Estimate
		93	uint8_t Status; // invalid/newdata/processed
		94	} __attribute__((packed)) ubx_nav_velned_t;
		95
		96	typedef struct
		97	{
		98	uint32_t itow; // ms GPS Millisecond Time of Week
		99	int32_t LON; // 1e-07 deg Longitude
		100	int32_t LAT; // 1e-07 deg Latitude
		101	int32_t HEIGHT; // mm Height above Ellipsoid
		102	int32_t HMSL; // mm Height above mean sea level
		103	uint32_t Hacc; // mm Horizontal Accuracy Estimate
		104	uint32_t Vacc; // mm Vertical Accuracy Estimate
		105	uint8_t Status; // invalid/newdata/processed
		106	} __attribute__((packed)) ubx_nav_posllh_t;
		107
		108
		109
		110	//------------------------------------------------------------------------------------
		111	// global variables
		112
		113	// local buffers for the incomming ubx messages
		114	volatile ubx_nav_sol_t UbxSol = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, INVALID};
		115	volatile ubx_nav_posllh_t UbxPosLlh = {0,0,0,0,0,0,0, INVALID};
		116	volatile ubx_nav_velned_t UbxVelNed = {0,0,0,0,0,0,0,0,0, INVALID};
		117
		118	uint16_t CheckGPSOkay = 0;
		119
		120	// shared buffer
		121	gps_data_t GPSData = {{0,0,0,INVALID},0,0,0,0,0,0,0, INVALID};
		122
		123	//------------------------------------------------------------------------------------
		124	// functions
		125
		126	uint8_t IsLeapYear(uint16_t year)
		127	{
		128	if((year%400 == 0) \|\| ( (year%4 == 0) && (year%100 != 0) ) ) return 1;
		129	else return 0;
		130	}
		131
		132	/********************************************************/
		133	/* Calculates the UTC Time from the GPS week and tow */
		134	/********************************************************/
		135	void SetGPSTime(DateTime_t * pTimeStruct)
		136	{
		137	uint32_t Days, Seconds, Week;
		138	uint16_t YearPart;
		139	uint32_t * MonthDayTab = 0;
		140	uint8_t i;
		141
		142
		143
		144	// if GPS data show valid time data
		145	if((UbxSol.Status != INVALID) && (UbxSol.Flags & FLAG_WKNSET) && (UbxSol.Flags & FLAG_TOWSET) )
		146	{
		147	Seconds = UbxSol.itow / 1000L;
		148	Week = (uint32_t)UbxSol.week;
		149	// correct leap seconds since 1980
		150	if(Seconds < LEAP_SECONDS_FROM_1980)
		151	{
		152	Week--;
		153	Seconds = SECONDS_PER_WEEK - LEAP_SECONDS_FROM_1980 + Seconds;
		154	}
		155	else Seconds -= LEAP_SECONDS_FROM_1980;
		156
		157	Days = DAYS_FROM_JAN01YEAR0001_TO_JAN6_1980;
		158	Days += (Week * DAYS_PER_WEEK);
		159	Days += Seconds / SECONDS_PER_DAY; // seperate days from GPS seconds of week
		160
		161	pTimeStruct->Year = 1;
		162	YearPart = (uint16_t)(Days / DAYS_PER_400YEARS);
		163	pTimeStruct->Year += YearPart * 400;
		164	Days = Days % DAYS_PER_400YEARS;
		165	YearPart = (uint16_t)(Days / DAYS_PER_100YEARS);
		166	pTimeStruct->Year += YearPart * 100;
		167	Days = Days % DAYS_PER_100YEARS;
		168	YearPart = (uint16_t)(Days / DAYS_PER_4YEARS);
		169	pTimeStruct->Year += YearPart * 4;
		170	Days = Days % DAYS_PER_4YEARS;
		171	if(Days < (3* DAYS_PER_YEAR)) YearPart = (uint16_t)(Days / DAYS_PER_YEAR);
		172	else YearPart = 3;
		173	pTimeStruct->Year += YearPart;
		174	// calculate remaining days of year
		175	Days -= (uint32_t)(YearPart * DAYS_PER_YEAR);
		176	Days += 1;
		177	// check if current year is a leap year
		178	if(IsLeapYear(pTimeStruct->Year)) MonthDayTab = (uint32_t*)Leap;
		179	else MonthDayTab = (uint32_t*)Normal;
		180	// seperate month and day from days of year
		181	for ( i = 0; i < 12; i++ )
		182	{
		183	if ( (MonthDayTab[i]< Days) && (Days <= MonthDayTab[i+1]) )
		184	{
		185	pTimeStruct->Month = i+1;
		186	pTimeStruct->Day = Days - MonthDayTab[i];
		187	i = 12;
		188	}
		189	}
		190	Seconds = Seconds % SECONDS_PER_DAY; // remaining seconds of current day
		191	pTimeStruct->Hour = (uint8_t)(Seconds / SECONDS_PER_HOUR);
		192	Seconds = Seconds % SECONDS_PER_HOUR; // remaining seconds of current hour
		193	pTimeStruct->Min = (uint8_t)(Seconds / SECONDS_PER_MINUTE);
		194	Seconds = Seconds % SECONDS_PER_MINUTE; // remaining seconds of current minute
		195	pTimeStruct->Sec = (uint8_t)(Seconds);
		196	pTimeStruct->mSec = (uint16_t)(UbxSol.itow % 1000L);
		197	pTimeStruct->Valid = 1;
		198	}
		199	else
		200	{
		201	pTimeStruct->Valid = 0;
		202	}
		203	}
		204
		205
		206
		207	/********************************************************/
		208	/* Initialize UBX Parser */
		209	/********************************************************/
		210	void UBX_Init(void)
		211	{
434	killagreg	212	printf("\r\n UBX init...");
426	killagreg	213	// mark msg buffers invalid
		214	UbxSol.Status = INVALID;
		215	UbxPosLlh.Status = INVALID;
		216	UbxVelNed.Status = INVALID;
		217	GPSData.Status = INVALID;
434	killagreg	218	printf("ok");
426	killagreg	219	}
		220
		221	/********************************************************/
		222	/* Upate GPS data stcructure */
		223	/********************************************************/
		224	void Update_GPSData (void)
		225	{
		226	static uint16_t Ubx_Timeout = 0;
		227	static uint8_t Msg_Count = 0;
		228
		229	// the timeout is used to detect the delay between two message sets
		230	// and is used for synchronisation so that always a set is collected
		231	// that belongs together
		232	// _______NAVSOL\|POSLLH\|VELNED\|___________________NAVSOL\|POSLLH\|VELNED\|_____________
		233	// \| 8ms \| 8ms \| 184 ms \| \| \|
		234	// msg_count: 0 1 2 0 1 2
		235
		236	if(CheckDelay(Ubx_Timeout)) Msg_Count = 0;
		237	else Msg_Count++;
		238	Ubx_Timeout = SetDelay(100); // reset ubx msg timeout
		239
		240	// if a new set of ubx messages was collected
		241	if((Msg_Count >= 2))
		242	{ // if set is complete
		243	if((UbxSol.Status == NEWDATA) && (UbxPosLlh.Status == NEWDATA) && (UbxVelNed.Status == NEWDATA))
		244	{
		245	CheckGPSOkay++;
		246	// update GPS data only if the status is INVALID or PROCESSED and the last ubx message was received within less than 100 ms
		247	if(GPSData.Status != NEWDATA) // if last data were processed
		248	{ // wait for new data at all neccesary ubx messages
		249	GPSData.Status = INVALID;
		250	// NAV SOL
		251	GPSData.Flags = UbxSol.Flags;
		252	GPSData.NumOfSats = UbxSol.numSV;
		253	GPSData.SatFix = UbxSol.GPSfix;
		254	GPSData.Position_Accuracy = UbxSol.PAcc;
		255	GPSData.Speed_Accuracy = UbxSol.SAcc;
		256	SetGPSTime(&SystemTime); // update system time
		257	// NAV POSLLH
		258	GPSData.Position.Status = INVALID;
		259	GPSData.Position.Longitude = UbxPosLlh.LON;
		260	GPSData.Position.Latitude = UbxPosLlh.LAT;
		261	GPSData.Position.Altitude = UbxPosLlh.HMSL;
		262	GPSData.Position.Status = NEWDATA;
		263	// NAV VELNED
		264	GPSData.Speed_East = UbxVelNed.VEL_E;
		265	GPSData.Speed_North = UbxVelNed.VEL_N;
		266	GPSData.Speed_Top = -UbxVelNed.VEL_D;
		267	GPSData.Speed_Ground = UbxVelNed.GSpeed;
		268	GPSData.Heading = UbxVelNed.Heading;
		269
		270	GPSData.Status = NEWDATA; // new data available
		271	} // EOF if(GPSData.Status != NEWDATA)
		272	} // EOF all ubx messages received
		273	// set state to collect new data
		274	UbxSol.Status = PROCESSED; // ready for new data
		275	UbxPosLlh.Status = PROCESSED; // ready for new data
		276	UbxVelNed.Status = PROCESSED; // ready for new data
		277	}
		278	}
		279
		280
		281	/********************************************************/
		282	/* UBX Parser */
		283	/********************************************************/
		284	void UBX_Parser(uint8_t c)
		285	{
		286	static ubxState_t ubxState = UBXSTATE_IDLE;
		287	static uint16_t msglen;
		288	static uint8_t cka, ckb;
		289	static uint8_t ubxP, ubxEp, *ubxSp; // pointers to data currently transfered
		290
		291
		292	//state machine
		293	switch (ubxState) // ubx message parser
		294	{
		295	case UBXSTATE_IDLE: // check 1st sync byte
		296	if (c == UBX_SYNC1_CHAR) ubxState = UBXSTATE_SYNC1;
		297	else ubxState = UBXSTATE_IDLE; // out of synchronization
		298	break;
		299
		300	case UBXSTATE_SYNC1: // check 2nd sync byte
		301	if (c == UBX_SYNC2_CHAR) ubxState = UBXSTATE_SYNC2;
		302	else ubxState = UBXSTATE_IDLE; // out of synchronization
		303	break;
		304
		305	case UBXSTATE_SYNC2: // check msg class to be NAV
		306	if (c == UBX_CLASS_NAV) ubxState = UBXSTATE_CLASS;
		307	else ubxState = UBXSTATE_IDLE; // unsupported message class
		308	break;
		309
		310	case UBXSTATE_CLASS: // check message identifier
		311	switch(c)
		312	{
		313	case UBX_ID_POSLLH: // geodetic position
		314	ubxP = (uint8_t *)&UbxPosLlh; // data start pointer
		315	ubxEp = (uint8_t *)(&UbxPosLlh + 1); // data end pointer
		316	ubxSp = (uint8_t *)&UbxPosLlh.Status; // status pointer
		317	break;
		318
		319	case UBX_ID_SOL: // navigation solution
		320	ubxP = (uint8_t *)&UbxSol; // data start pointer
		321	ubxEp = (uint8_t *)(&UbxSol + 1); // data end pointer
		322	ubxSp = (uint8_t *)&UbxSol.Status; // status pointer
		323	break;
		324
		325	case UBX_ID_VELNED: // velocity vector in tangent plane
		326	ubxP = (uint8_t *)&UbxVelNed; // data start pointer
		327	ubxEp = (uint8_t *)(&UbxVelNed + 1); // data end pointer
		328	ubxSp = (uint8_t *)&UbxVelNed.Status; // status pointer
		329	break;
		330
		331	default: // unsupported identifier
		332	ubxState = UBXSTATE_IDLE;
		333	break;
		334	}
		335	if (ubxState != UBXSTATE_IDLE)
		336	{
		337	ubxState = UBXSTATE_LEN1;
		338	cka = UBX_CLASS_NAV + c;
		339	ckb = UBX_CLASS_NAV + cka;
		340	}
		341	break;
		342
		343	case UBXSTATE_LEN1: // 1st message length byte
		344	msglen = (uint16_t)c; // lowbyte first
		345	cka += c;
		346	ckb += cka;
		347	ubxState = UBXSTATE_LEN2;
		348	break;
		349
		350	case UBXSTATE_LEN2: // 2nd message length byte
		351	msglen += ((uint16_t)c)<<8; // high byte last
		352	cka += c;
		353	ckb += cka;
		354	// if the old data are not processed so far then break parsing now
		355	// to avoid writing new data in ISR during reading by another function
		356	if ( *ubxSp == NEWDATA )
		357	{
		358	ubxState = UBXSTATE_IDLE;
		359	Update_GPSData(); //update GPS info respectively
		360	}
		361	else // data invalid or allready processd
		362	{
		363	*ubxSp = INVALID; // mark invalid during buffer filling
		364	ubxState = UBXSTATE_DATA;
		365	}
		366	break;
		367
		368	case UBXSTATE_DATA: // collecting data
		369	if (ubxP < ubxEp)
		370	{
		371	*ubxP++ = c; // copy curent data byte if any space is left
		372	cka += c;
		373	ckb += cka;
		374	if (--msglen == 0) ubxState = UBXSTATE_CKA; // switch to next state if all data was read
		375	}
		376	else // rx buffer overrun
		377	{
		378	ubxState = UBXSTATE_IDLE;
		379	}
		380	break;
		381
		382	case UBXSTATE_CKA:
		383	if (c == cka) ubxState = UBXSTATE_CKB;
		384	else
		385	{
		386	*ubxSp = INVALID;
		387	ubxState = UBXSTATE_IDLE;
		388	}
		389	break;
		390
		391	case UBXSTATE_CKB:
		392	if (c == ckb)
		393	{
		394	*ubxSp = NEWDATA; // new data are valid
		395	Update_GPSData(); //update GPS info respectively
		396	}
		397	else
		398	{ // if checksum not match then set data invalid
		399	*ubxSp = INVALID;
		400	}
		401	ubxState = UBXSTATE_IDLE; // ready to parse new data
		402	break;
		403
		404	default: // unknown ubx state
		405	ubxState = UBXSTATE_IDLE;
		406	break;
		407
		408	}
		409	}

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