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| Rev | Author | Line No. | Line |
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| 231 | killagreg | 1 | #include <inttypes.h> |
| 2 | |||
| 3 | #include "ubx.h" |
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| 4 | #include <avr/io.h> |
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| 5 | |||
| 6 | |||
| 7 | // ubx protocol parser state machine |
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| 8 | #define UBXSTATE_IDLE 0 |
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| 9 | #define UBXSTATE_SYNC1 1 |
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| 10 | #define UBXSTATE_SYNC2 2 |
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| 11 | #define UBXSTATE_CLASS 3 |
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| 12 | #define UBXSTATE_LEN1 4 |
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| 13 | #define UBXSTATE_LEN2 5 |
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| 14 | #define UBXSTATE_DATA 6 |
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| 15 | #define UBXSTATE_CKA 7 |
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| 16 | #define UBXSTATE_CKB 8 |
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| 17 | |||
| 18 | // ublox protocoll identifier |
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| 19 | #define UBX_CLASS_NAV 0x01 |
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| 20 | |||
| 21 | #define UBX_ID_POSLLH 0x02 |
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| 22 | #define UBX_ID_SOL 0x06 |
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| 23 | #define UBX_ID_VELNED 0x12 |
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| 24 | |||
| 25 | #define UBX_SYNC1_CHAR 0xB5 |
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| 26 | #define UBX_SYNC2_CHAR 0x62 |
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| 27 | |||
| 28 | typedef struct { |
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| 29 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 30 | int32_t Frac; // ns remainder of rounded ms above |
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| 31 | int16_t week; // GPS week |
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| 32 | uint8_t GPSfix; // GPSfix Type, range 0..6 |
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| 33 | uint8_t Flags; // Navigation Status Flags |
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| 34 | int32_t ECEF_X; // cm ECEF X coordinate |
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| 35 | int32_t ECEF_Y; // cm ECEF Y coordinate |
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| 36 | int32_t ECEF_Z; // cm ECEF Z coordinate |
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| 37 | uint32_t PAcc; // cm 3D Position Accuracy Estimate |
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| 38 | int32_t ECEFVX; // cm/s ECEF X velocity |
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| 39 | int32_t ECEFVY; // cm/s ECEF Y velocity |
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| 40 | int32_t ECEFVZ; // cm/s ECEF Z velocity |
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| 41 | uint32_t SAcc; // cm/s Speed Accuracy Estimate |
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| 42 | uint16_t PDOP; // 0.01 Position DOP |
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| 43 | uint8_t res1; // reserved |
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| 44 | uint8_t numSV; // Number of SVs used in navigation solution |
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| 45 | uint32_t res2; // reserved |
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| 46 | Status_t Status; |
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| 47 | } UBX_SOL_t; |
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| 48 | |||
| 49 | typedef struct { |
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| 50 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 51 | int32_t LON; // 1e-07 deg Longitude |
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| 52 | int32_t LAT; // 1e-07 deg Latitude |
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| 53 | int32_t HEIGHT; // mm Height above Ellipsoid |
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| 54 | int32_t HMSL; // mm Height above mean sea level |
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| 55 | uint32_t Hacc; // mm Horizontal Accuracy Estimate |
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| 56 | uint32_t Vacc; // mm Vertical Accuracy Estimate |
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| 57 | Status_t Status; |
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| 58 | } UBX_POSLLH_t; |
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| 59 | |||
| 60 | typedef struct { |
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| 61 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 62 | int32_t VEL_N; // cm/s NED north velocity |
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| 63 | int32_t VEL_E; // cm/s NED east velocity |
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| 64 | int32_t VEL_D; // cm/s NED down velocity |
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| 65 | uint32_t Speed; // cm/s Speed (3-D) |
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| 66 | uint32_t GSpeed; // cm/s Ground Speed (2-D) |
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| 67 | int32_t Heading; // 1e-05 deg Heading 2-D |
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| 68 | uint32_t SAcc; // cm/s Speed Accuracy Estimate |
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| 69 | uint32_t CAcc; // deg Course / Heading Accuracy Estimate |
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| 70 | Status_t Status; |
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| 71 | } UBX_VELNED_t; |
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| 72 | |||
| 73 | UBX_SOL_t UbxSol = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, INVALID}; |
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| 74 | UBX_POSLLH_t UbxPosLlh = {0,0,0,0,0,0,0, INVALID}; |
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| 75 | UBX_VELNED_t UbxVelNed = {0,0,0,0,0,0,0,0,0, INVALID}; |
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| 76 | GPS_INFO_t GPSInfo = {0,0,0,0,0,0,0,0,0,0, INVALID}; |
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| 77 | |||
| 78 | volatile uint8_t GPSTimeout = 0; |
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| 79 | |||
| 80 | void UpdateGPSInfo (void) |
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| 81 | { |
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| 82 | |||
| 83 | if ((UbxSol.Status == NEWDATA) && (UbxPosLlh.Status == NEWDATA) && (UbxVelNed.Status == NEWDATA)) |
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| 84 | { |
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| 85 | if(GPSInfo.status != NEWDATA) |
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| 86 | { |
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| 87 | GPSInfo.status = INVALID; |
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| 88 | // NAV SOL |
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| 89 | GPSInfo.flags = UbxSol.Flags; |
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| 90 | GPSInfo.satfix = UbxSol.GPSfix; |
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| 91 | GPSInfo.satnum = UbxSol.numSV; |
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| 92 | GPSInfo.PAcc = UbxSol.PAcc; |
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| 93 | GPSInfo.VAcc = UbxSol.SAcc; |
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| 94 | // NAV POSLLH |
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| 95 | GPSInfo.longitude = UbxPosLlh.LON; |
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| 96 | GPSInfo.latitude = UbxPosLlh.LAT; |
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| 97 | GPSInfo.altitude = UbxPosLlh.HEIGHT; |
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| 98 | |||
| 99 | GPSInfo.veleast = UbxVelNed.VEL_E; |
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| 100 | GPSInfo.velnorth = UbxVelNed.VEL_N; |
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| 101 | GPSInfo.veltop = -UbxVelNed.VEL_D; |
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| 102 | GPSInfo.velground = UbxVelNed.GSpeed; |
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| 103 | |||
| 104 | GPSInfo.status = NEWDATA; |
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| 105 | |||
| 106 | } |
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| 107 | // set state to collect new data |
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| 108 | UbxSol.Status = PROCESSED; // never update old data |
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| 109 | UbxPosLlh.Status = PROCESSED; // never update old data |
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| 110 | UbxVelNed.Status = PROCESSED; // never update old data |
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| 111 | } |
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| 112 | |||
| 113 | |||
| 114 | } |
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| 115 | |||
| 116 | |||
| 117 | // this function should be called within the UART RX ISR |
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| 118 | void ubx_parser(uint8_t c) |
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| 119 | { |
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| 120 | static uint8_t ubxstate = UBXSTATE_IDLE; |
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| 121 | static uint8_t cka, ckb; |
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| 122 | static uint16_t msglen; |
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| 123 | static int8_t *ubxP, *ubxEp, *ubxSp; // pointers to data currently transfered |
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| 124 | |||
| 125 | switch(ubxstate) |
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| 126 | { |
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| 127 | case UBXSTATE_IDLE: // check 1st sync byte |
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| 128 | if (c == UBX_SYNC1_CHAR) ubxstate = UBXSTATE_SYNC1; |
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| 129 | else ubxstate = UBXSTATE_IDLE; // out of synchronization |
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| 130 | break; |
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| 131 | |||
| 132 | case UBXSTATE_SYNC1: // check 2nd sync byte |
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| 133 | if (c == UBX_SYNC2_CHAR) ubxstate = UBXSTATE_SYNC2; |
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| 134 | else ubxstate = UBXSTATE_IDLE; // out of synchronization |
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| 135 | break; |
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| 136 | |||
| 137 | case UBXSTATE_SYNC2: // check msg class to be NAV |
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| 138 | if (c == UBX_CLASS_NAV) ubxstate = UBXSTATE_CLASS; |
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| 139 | else ubxstate = UBXSTATE_IDLE; // unsupported message class |
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| 140 | break; |
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| 141 | |||
| 142 | case UBXSTATE_CLASS: // check message identifier |
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| 143 | switch(c) |
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| 144 | { |
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| 145 | case UBX_ID_POSLLH: // geodetic position |
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| 146 | ubxP = (int8_t *)&UbxPosLlh; // data start pointer |
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| 147 | ubxEp = (int8_t *)(&UbxPosLlh + 1); // data end pointer |
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| 148 | ubxSp = (int8_t *)&UbxPosLlh.Status; // status pointer |
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| 149 | break; |
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| 150 | |||
| 151 | case UBX_ID_SOL: // navigation solution |
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| 152 | ubxP = (int8_t *)&UbxSol; // data start pointer |
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| 153 | ubxEp = (int8_t *)(&UbxSol + 1); // data end pointer |
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| 154 | ubxSp = (int8_t *)&UbxSol.Status; // status pointer |
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| 155 | break; |
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| 156 | |||
| 157 | case UBX_ID_VELNED: // velocity vector in tangent plane |
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| 158 | ubxP = (int8_t *)&UbxVelNed; // data start pointer |
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| 159 | ubxEp = (int8_t *)(&UbxVelNed + 1); // data end pointer |
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| 160 | ubxSp = (int8_t *)&UbxVelNed.Status; // status pointer |
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| 161 | break; |
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| 162 | |||
| 163 | default: // unsupported identifier |
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| 164 | ubxstate = UBXSTATE_IDLE; |
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| 165 | break; |
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| 166 | } |
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| 167 | if (ubxstate != UBXSTATE_IDLE) |
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| 168 | { |
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| 169 | ubxstate = UBXSTATE_LEN1; |
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| 170 | cka = UBX_CLASS_NAV + c; |
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| 171 | ckb = UBX_CLASS_NAV + cka; |
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| 172 | } |
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| 173 | break; |
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| 174 | |||
| 175 | case UBXSTATE_LEN1: // 1st message length byte |
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| 176 | msglen = c; |
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| 177 | cka += c; |
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| 178 | ckb += cka; |
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| 179 | ubxstate = UBXSTATE_LEN2; |
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| 180 | break; |
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| 181 | |||
| 182 | case UBXSTATE_LEN2: // 2nd message length byte |
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| 183 | msglen += ((uint16_t)c)<<8; |
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| 184 | cka += c; |
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| 185 | ckb += cka; |
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| 186 | // if the old data are not processed so far then break parsing now |
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| 187 | // to avoid writing new data in ISR during reading by another function |
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| 188 | if ( *ubxSp == NEWDATA ) |
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| 189 | { |
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| 190 | UpdateGPSInfo(); //update GPS info respectively |
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| 191 | ubxstate = UBXSTATE_IDLE; |
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| 192 | } |
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| 193 | else // data invalid or allready processd |
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| 194 | { |
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| 195 | *ubxSp = INVALID; |
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| 196 | ubxstate = UBXSTATE_DATA; |
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| 197 | } |
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| 198 | break; |
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| 199 | |||
| 200 | case UBXSTATE_DATA: |
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| 201 | if (ubxP < ubxEp) *ubxP++ = c; // copy curent data byte if any space is left |
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| 202 | cka += c; |
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| 203 | ckb += cka; |
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| 204 | if (--msglen == 0) ubxstate = UBXSTATE_CKA; // switch to next state if all data was read |
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| 205 | break; |
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| 206 | |||
| 207 | case UBXSTATE_CKA: |
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| 208 | if (c == cka) ubxstate = UBXSTATE_CKB; |
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| 209 | else |
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| 210 | { |
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| 211 | *ubxSp = INVALID; |
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| 212 | ubxstate = UBXSTATE_IDLE; |
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| 213 | } |
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| 214 | break; |
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| 215 | |||
| 216 | case UBXSTATE_CKB: |
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| 217 | if (c == ckb) |
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| 218 | { |
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| 219 | *ubxSp = NEWDATA; // new data are valid |
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| 220 | UpdateGPSInfo(); //update GPS info respectively |
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| 221 | GPSTimeout = 255; |
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| 222 | } |
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| 223 | else |
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| 224 | { // if checksum not fit then set data invalid |
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| 225 | *ubxSp = INVALID; |
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| 226 | } |
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| 227 | ubxstate = UBXSTATE_IDLE; // ready to parse new data |
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| 228 | break; |
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| 229 | |||
| 230 | default: // unknown ubx state |
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| 231 | ubxstate = UBXSTATE_IDLE; |
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| 232 | break; |
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| 233 | } |
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| 234 | |||
| 235 | } |
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| 236 | |||
| 237 |