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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 684 | killagreg | 1 | #include <inttypes.h> |
| 2 | #include "ubx.h" |
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| 3 | |||
| 4 | // ubx protocol parser state machine |
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| 5 | #define UBXSTATE_IDLE 0 |
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| 6 | #define UBXSTATE_SYNC1 1 |
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| 7 | #define UBXSTATE_SYNC2 2 |
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| 8 | #define UBXSTATE_CLASS 3 |
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| 9 | #define UBXSTATE_LEN1 4 |
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| 10 | #define UBXSTATE_LEN2 5 |
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| 11 | #define UBXSTATE_DATA 6 |
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| 12 | #define UBXSTATE_CKA 7 |
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| 13 | #define UBXSTATE_CKB 8 |
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| 14 | |||
| 15 | // ublox protocoll identifier |
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| 16 | #define UBX_CLASS_NAV 0x01 |
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| 17 | #define UBX_ID_POSLLH 0x02 |
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| 18 | #define UBX_ID_POSUTM 0x08 |
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| 19 | #define UBX_ID_STATUS 0x03 |
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| 20 | #define UBX_ID_VELNED 0x12 |
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| 21 | #define UBX_SYNC1_CHAR 0xB5 |
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| 22 | #define UBX_SYNC2_CHAR 0x62 |
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| 23 | |||
| 24 | |||
| 25 | typedef struct { |
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| 26 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 27 | uint8_t GPSfix; // GPSfix Type, range 0..6 |
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| 28 | uint8_t Flags; // Navigation Status Flags |
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| 29 | uint8_t DiffS; // Differential Status |
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| 30 | uint8_t res; // reserved |
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| 31 | uint32_t TTFF; // Time to first fix (millisecond time tag) |
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| 32 | uint32_t MSSS; // Milliseconds since Startup / Reset |
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| 33 | uint8_t packetStatus; |
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| 34 | } GPS_STATUS_t; |
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| 35 | |||
| 36 | typedef struct { |
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| 37 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 38 | int32_t LON; // 1e-07 deg Longitude |
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| 39 | int32_t LAT; // 1e-07 deg Latitude |
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| 40 | int32_t HEIGHT; // mm Height above Ellipsoid |
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| 41 | int32_t HMSL; // mm Height above mean sea level |
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| 42 | uint32_t Hacc; // mm Horizontal Accuracy Estimate |
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| 43 | uint32_t Vacc; // mm Vertical Accuracy Estimate |
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| 44 | uint8_t packetStatus; |
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| 45 | } GPS_POSLLH_t; |
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| 46 | |||
| 47 | typedef struct { |
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| 48 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 49 | int32_t EAST; // cm UTM Easting |
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| 50 | int32_t NORTH; // cm UTM Nording |
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| 51 | int32_t ALT; // cm altitude |
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| 52 | uint8_t ZONE; // UTM zone number |
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| 53 | uint8_t HEM; // Hemisphere Indicator (0=North, 1=South) |
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| 54 | uint8_t packetStatus; |
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| 55 | } GPS_POSUTM_t; |
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| 56 | |||
| 57 | typedef struct { |
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| 58 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 59 | int32_t VEL_N; // cm/s NED north velocity |
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| 60 | int32_t VEL_E; // cm/s NED east velocity |
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| 61 | int32_t VEL_D; // cm/s NED down velocity |
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| 62 | uint32_t Speed; // cm/s Speed (3-D) |
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| 63 | uint32_t GSpeed; // cm/s Ground Speed (2-D) |
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| 64 | int32_t Heading; // 1e-05 deg Heading 2-D |
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| 65 | uint32_t SAcc; // cm/s Speed Accuracy Estimate |
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| 66 | uint32_t CAcc; // deg Course / Heading Accuracy Estimate |
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| 67 | uint8_t packetStatus; |
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| 68 | } GPS_VELNED_t; |
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| 69 | |||
| 70 | |||
| 71 | GPS_STATUS_t GpsStatus; |
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| 72 | GPS_POSLLH_t GpsPosLlh; |
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| 73 | GPS_POSUTM_t GpsPosUtm; |
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| 74 | GPS_VELNED_t GpsVelNed; |
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| 75 | |||
| 76 | GPS_INFO_t actualPos; |
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| 77 | |||
| 78 | void UpdateGPSInfo (void) |
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| 79 | { |
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| 80 | if (GpsStatus.packetStatus == VALID) // valid packet |
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| 81 | { |
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| 82 | actualPos.satfix = GpsStatus.GPSfix; |
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| 83 | GpsStatus.packetStatus = PROCESSED; // never update old data |
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| 84 | } |
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| 85 | if (GpsPosLlh.packetStatus == VALID) // valid packet |
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| 86 | { |
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| 87 | actualPos.longitude = GpsPosLlh.LON; |
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| 88 | actualPos.latitude = GpsPosLlh.LAT; |
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| 89 | actualPos.altitude = GpsPosLlh.HEIGHT; |
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| 90 | GpsPosLlh.packetStatus = PROCESSED; // never update old data |
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| 91 | } |
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| 92 | if (GpsPosUtm.packetStatus == VALID) // valid packet |
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| 93 | { |
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| 94 | actualPos.utmeast = GpsPosUtm.EAST; |
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| 95 | actualPos.utmnorth = GpsPosUtm.NORTH; |
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| 96 | actualPos.utmalt = GpsPosUtm.ALT; |
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| 97 | GpsPosUtm.packetStatus = PROCESSED; // never update old data |
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| 98 | } |
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| 99 | if (GpsVelNed.packetStatus == VALID) // valid packet |
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| 100 | { |
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| 101 | actualPos.veleast = GpsVelNed.VEL_E; |
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| 102 | actualPos.velnorth = GpsVelNed.VEL_N; |
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| 103 | actualPos.veltop = -GpsVelNed.VEL_D; |
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| 104 | GpsPosUtm.packetStatus = PROCESSED; // never update old data |
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| 105 | } |
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| 106 | } |
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| 107 | |||
| 108 | // this function should be called within the UART RX ISR |
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| 109 | void ubx_parser(uint8_t c) |
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| 110 | { |
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| 111 | static uint8_t ubxstate = UBXSTATE_IDLE; |
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| 112 | static uint8_t cka, ckb; |
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| 113 | static uint16_t msglen; |
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| 114 | static int8_t *ubxP, *ubxEp, *ubxSp; // pointers to data currently transfered |
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| 115 | |||
| 116 | switch(ubxstate) |
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| 117 | { |
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| 118 | case UBXSTATE_IDLE: // check 1st sync byte |
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| 119 | if (c == UBX_SYNC1_CHAR) ubxstate = UBXSTATE_SYNC1; |
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| 120 | else ubxstate = UBXSTATE_IDLE; // out of synchronization |
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| 121 | break; |
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| 122 | |||
| 123 | case UBXSTATE_SYNC1: // check 2nd sync byte |
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| 124 | if (c == UBX_SYNC2_CHAR) ubxstate = UBXSTATE_SYNC2; |
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| 125 | else ubxstate = UBXSTATE_IDLE; // out of synchronization |
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| 126 | break; |
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| 127 | |||
| 128 | case UBXSTATE_SYNC2: // check msg class to be NAV |
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| 129 | if (c == UBX_CLASS_NAV) ubxstate = UBXSTATE_CLASS; |
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| 130 | else ubxstate = UBXSTATE_IDLE; // unsupported message class |
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| 131 | break; |
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| 132 | |||
| 133 | case UBXSTATE_CLASS: // check message identifier |
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| 134 | switch(c) |
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| 135 | { |
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| 136 | case UBX_ID_POSUTM: // utm position |
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| 137 | ubxP = (int8_t *)&GpsPosUtm; // data start pointer |
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| 138 | ubxEp = (int8_t *)(&GpsPosUtm + sizeof(GPS_POSUTM_t)); // data end pointer |
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| 139 | ubxSp = (int8_t *)&GpsPosUtm.packetStatus; // status pointer |
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| 140 | |||
| 141 | break; |
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| 142 | |||
| 143 | case UBX_ID_POSLLH: // geodetic position |
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| 144 | ubxP = (int8_t *)&GpsStatus; // data start pointer |
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| 145 | ubxEp = (int8_t *)(&GpsStatus + sizeof(GPS_STATUS_t)); // data end pointer |
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| 146 | ubxSp = (int8_t *)&GpsStatus.packetStatus; // status pointer |
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| 147 | break; |
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| 148 | |||
| 149 | case UBX_ID_STATUS: // receiver status |
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| 150 | ubxP = (int8_t *)&GpsStatus; // data start pointer |
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| 151 | ubxEp = (int8_t *)(&GpsStatus + sizeof(GPS_STATUS_t)); // data end pointer |
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| 152 | ubxSp = (int8_t *)&GpsStatus.packetStatus; // status pointer |
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| 153 | break; |
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| 154 | |||
| 155 | case UBX_ID_VELNED: // velocity vector in tangent plane |
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| 156 | ubxP = (int8_t *)&GpsVelNed; // data start pointer |
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| 157 | ubxEp = (int8_t *)(&GpsVelNed + sizeof(GPS_VELNED_t)); // data end pointer |
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| 158 | ubxSp = (int8_t *)&GpsVelNed.packetStatus; // status pointer |
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| 159 | break; |
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| 160 | |||
| 161 | default: // unsupported identifier |
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| 162 | ubxstate = UBXSTATE_IDLE; |
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| 163 | break; |
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| 164 | } |
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| 165 | if (ubxstate != UBXSTATE_IDLE) |
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| 166 | { |
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| 167 | ubxstate = UBXSTATE_LEN1; |
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| 168 | cka = UBX_CLASS_NAV + c; |
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| 169 | ckb = UBX_CLASS_NAV + cka; |
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| 170 | } |
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| 171 | break; |
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| 172 | |||
| 173 | case UBXSTATE_LEN1: // 1st message length byte |
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| 174 | msglen = c; |
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| 175 | cka += c; |
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| 176 | ckb += cka; |
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| 177 | ubxstate = UBXSTATE_LEN2; |
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| 178 | break; |
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| 179 | |||
| 180 | case UBXSTATE_LEN2: // 2nd message length byte |
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| 181 | msglen += ((uint16_t)c)<<8; |
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| 182 | cka += c; |
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| 183 | ckb += cka; |
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| 184 | // if the old data are not processed so far then break parsing now |
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| 185 | // to avoid writing new data in ISR during reading by another function |
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| 186 | if ( *ubxSp == VALID ) ubxstate = UBXSTATE_IDLE; |
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| 187 | else // data invalid or allready processd |
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| 188 | { |
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| 189 | *ubxSp = INVALID; |
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| 190 | ubxstate = UBXSTATE_DATA; |
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| 191 | } |
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| 192 | break; |
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| 193 | |||
| 194 | case UBXSTATE_DATA: |
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| 195 | if (ubxP < ubxEp) *ubxP++ = c; // copy curent data byte if any space is left |
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| 196 | cka += c; |
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| 197 | ckb += cka; |
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| 198 | if (--msglen == 0) ubxstate = UBXSTATE_CKA; // switch to next state if all data was read |
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| 199 | break; |
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| 200 | |||
| 201 | case UBXSTATE_CKA: |
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| 202 | if (c == cka) ubxstate = UBXSTATE_CKB; |
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| 203 | else ubxstate = UBXSTATE_IDLE; |
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| 204 | break; |
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| 205 | |||
| 206 | case UBXSTATE_CKB: |
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| 207 | if (c == ckb) |
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| 208 | { |
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| 209 | *ubxSp = VALID; // new data are availabe |
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| 210 | UpdateGPSInfo(); //update GPS info respectively |
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| 211 | } |
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| 212 | ubxstate = UBXSTATE_IDLE; // ready to parse new data |
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| 213 | break; |
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| 214 | |||
| 215 | default: // unknown ubx state |
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| 216 | ubxstate = UBXSTATE_IDLE; |
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| 217 | break; |
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| 218 | } |
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| 219 | |||
| 220 | } |
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| 221 |