WebSVN - Projects - Blame - Rev 274

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

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