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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 684 | killagreg | 1 | #include <inttypes.h> |
| 2 | #include "ubx.h" |
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| 702 | killagreg | 3 | #include "main.h" |
| 4 | #include <avr/io.h> |
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| 684 | killagreg | 5 | |
| 722 | killagreg | 6 | #include "uart.h" |
| 7 | #include "timer0.h" |
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| 8 | |||
| 684 | killagreg | 9 | // ubx protocol parser state machine |
| 10 | #define UBXSTATE_IDLE 0 |
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| 11 | #define UBXSTATE_SYNC1 1 |
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| 12 | #define UBXSTATE_SYNC2 2 |
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| 13 | #define UBXSTATE_CLASS 3 |
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| 14 | #define UBXSTATE_LEN1 4 |
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| 15 | #define UBXSTATE_LEN2 5 |
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| 16 | #define UBXSTATE_DATA 6 |
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| 17 | #define UBXSTATE_CKA 7 |
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| 18 | #define UBXSTATE_CKB 8 |
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| 19 | |||
| 20 | // ublox protocoll identifier |
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| 21 | #define UBX_CLASS_NAV 0x01 |
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| 22 | #define UBX_ID_POSLLH 0x02 |
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| 23 | #define UBX_ID_POSUTM 0x08 |
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| 24 | #define UBX_ID_STATUS 0x03 |
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| 25 | #define UBX_ID_VELNED 0x12 |
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| 26 | #define UBX_SYNC1_CHAR 0xB5 |
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| 27 | #define UBX_SYNC2_CHAR 0x62 |
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| 28 | |||
| 29 | |||
| 30 | typedef struct { |
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| 31 | uint32_t ITOW; // ms GPS Millisecond Time of 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 | uint8_t DiffS; // Differential Status |
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| 35 | uint8_t res; // reserved |
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| 36 | uint32_t TTFF; // Time to first fix (millisecond time tag) |
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| 37 | uint32_t MSSS; // Milliseconds since Startup / Reset |
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| 702 | killagreg | 38 | uint8_t Status; |
| 684 | killagreg | 39 | } GPS_STATUS_t; |
| 40 | |||
| 41 | typedef struct { |
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| 42 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 43 | int32_t LON; // 1e-07 deg Longitude |
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| 44 | int32_t LAT; // 1e-07 deg Latitude |
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| 45 | int32_t HEIGHT; // mm Height above Ellipsoid |
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| 46 | int32_t HMSL; // mm Height above mean sea level |
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| 47 | uint32_t Hacc; // mm Horizontal Accuracy Estimate |
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| 48 | uint32_t Vacc; // mm Vertical Accuracy Estimate |
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| 702 | killagreg | 49 | uint8_t Status; |
| 684 | killagreg | 50 | } GPS_POSLLH_t; |
| 51 | |||
| 52 | typedef struct { |
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| 53 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 54 | int32_t EAST; // cm UTM Easting |
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| 55 | int32_t NORTH; // cm UTM Nording |
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| 56 | int32_t ALT; // cm altitude |
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| 57 | uint8_t ZONE; // UTM zone number |
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| 58 | uint8_t HEM; // Hemisphere Indicator (0=North, 1=South) |
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| 702 | killagreg | 59 | uint8_t Status; |
| 684 | killagreg | 60 | } GPS_POSUTM_t; |
| 61 | |||
| 62 | typedef struct { |
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| 63 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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| 64 | int32_t VEL_N; // cm/s NED north velocity |
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| 65 | int32_t VEL_E; // cm/s NED east velocity |
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| 66 | int32_t VEL_D; // cm/s NED down velocity |
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| 67 | uint32_t Speed; // cm/s Speed (3-D) |
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| 68 | uint32_t GSpeed; // cm/s Ground Speed (2-D) |
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| 69 | int32_t Heading; // 1e-05 deg Heading 2-D |
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| 70 | uint32_t SAcc; // cm/s Speed Accuracy Estimate |
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| 71 | uint32_t CAcc; // deg Course / Heading Accuracy Estimate |
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| 702 | killagreg | 72 | uint8_t Status; |
| 684 | killagreg | 73 | } GPS_VELNED_t; |
| 74 | |||
| 75 | |||
| 76 | GPS_STATUS_t GpsStatus; |
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| 77 | GPS_POSLLH_t GpsPosLlh; |
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| 78 | GPS_POSUTM_t GpsPosUtm; |
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| 79 | GPS_VELNED_t GpsVelNed; |
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| 80 | |||
| 702 | killagreg | 81 | GPS_INFO_t GPSInfo; |
| 684 | killagreg | 82 | |
| 83 | void UpdateGPSInfo (void) |
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| 84 | { |
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| 702 | killagreg | 85 | if (GpsStatus.Status == VALID) // valid packet |
| 684 | killagreg | 86 | { |
| 702 | killagreg | 87 | GPSInfo.satfix = GpsStatus.GPSfix; |
| 88 | GpsStatus.Status = PROCESSED; // never update old data |
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| 684 | killagreg | 89 | } |
| 702 | killagreg | 90 | if (GpsPosLlh.Status == VALID) // valid packet |
| 684 | killagreg | 91 | { |
| 702 | killagreg | 92 | GPSInfo.longitude = GpsPosLlh.LON; |
| 93 | GPSInfo.latitude = GpsPosLlh.LAT; |
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| 94 | GPSInfo.altitude = GpsPosLlh.HEIGHT; |
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| 95 | GpsPosLlh.Status = PROCESSED; // never update old data |
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| 684 | killagreg | 96 | } |
| 702 | killagreg | 97 | if (GpsPosUtm.Status == VALID) // valid packet |
| 684 | killagreg | 98 | { |
| 702 | killagreg | 99 | GPSInfo.utmeast = GpsPosUtm.EAST; |
| 100 | GPSInfo.utmnorth = GpsPosUtm.NORTH; |
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| 101 | GPSInfo.utmalt = GpsPosUtm.ALT; |
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| 102 | GpsPosUtm.Status = PROCESSED; // never update old data |
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| 684 | killagreg | 103 | } |
| 702 | killagreg | 104 | if (GpsVelNed.Status == VALID) // valid packet |
| 684 | killagreg | 105 | { |
| 702 | killagreg | 106 | GPSInfo.veleast = GpsVelNed.VEL_E; |
| 107 | GPSInfo.velnorth = GpsVelNed.VEL_N; |
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| 108 | GPSInfo.veltop = -GpsVelNed.VEL_D; |
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| 109 | GpsPosUtm.Status = PROCESSED; // never update old data |
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| 684 | killagreg | 110 | } |
| 722 | killagreg | 111 | if (GpsStatus.Status != INVALID) |
| 702 | killagreg | 112 | { |
| 722 | killagreg | 113 | GPSInfo.status = VALID; // set valid if data are updated |
| 702 | killagreg | 114 | } |
| 684 | killagreg | 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_POSUTM: // utm position |
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| 146 | ubxP = (int8_t *)&GpsPosUtm; // data start pointer |
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| 147 | ubxEp = (int8_t *)(&GpsPosUtm + sizeof(GPS_POSUTM_t)); // data end pointer |
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| 702 | killagreg | 148 | ubxSp = (int8_t *)&GpsPosUtm.Status; // status pointer |
| 684 | killagreg | 149 | break; |
| 150 | |||
| 151 | case UBX_ID_POSLLH: // geodetic position |
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| 722 | killagreg | 152 | ubxP = (int8_t *)&GpsPosLlh; // data start pointer |
| 153 | ubxEp = (int8_t *)(&GpsPosLlh + sizeof(GPS_POSLLH_t)); // data end pointer |
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| 154 | ubxSp = (int8_t *)&GpsPosLlh.Status; // status pointer |
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| 684 | killagreg | 155 | break; |
| 156 | |||
| 157 | case UBX_ID_STATUS: // receiver status |
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| 158 | ubxP = (int8_t *)&GpsStatus; // data start pointer |
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| 159 | ubxEp = (int8_t *)(&GpsStatus + sizeof(GPS_STATUS_t)); // data end pointer |
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| 702 | killagreg | 160 | ubxSp = (int8_t *)&GpsStatus.Status; // status pointer |
| 684 | killagreg | 161 | break; |
| 162 | |||
| 163 | case UBX_ID_VELNED: // velocity vector in tangent plane |
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| 164 | ubxP = (int8_t *)&GpsVelNed; // data start pointer |
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| 165 | ubxEp = (int8_t *)(&GpsVelNed + sizeof(GPS_VELNED_t)); // data end pointer |
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| 702 | killagreg | 166 | ubxSp = (int8_t *)&GpsVelNed.Status; // status pointer |
| 684 | killagreg | 167 | break; |
| 168 | |||
| 169 | default: // unsupported identifier |
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| 170 | ubxstate = UBXSTATE_IDLE; |
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| 171 | break; |
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| 172 | } |
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| 173 | if (ubxstate != UBXSTATE_IDLE) |
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| 174 | { |
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| 175 | ubxstate = UBXSTATE_LEN1; |
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| 176 | cka = UBX_CLASS_NAV + c; |
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| 177 | ckb = UBX_CLASS_NAV + cka; |
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| 178 | } |
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| 179 | break; |
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| 180 | |||
| 181 | case UBXSTATE_LEN1: // 1st message length byte |
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| 182 | msglen = c; |
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| 183 | cka += c; |
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| 184 | ckb += cka; |
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| 185 | ubxstate = UBXSTATE_LEN2; |
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| 186 | break; |
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| 187 | |||
| 188 | case UBXSTATE_LEN2: // 2nd message length byte |
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| 189 | msglen += ((uint16_t)c)<<8; |
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| 190 | cka += c; |
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| 191 | ckb += cka; |
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| 192 | // if the old data are not processed so far then break parsing now |
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| 193 | // to avoid writing new data in ISR during reading by another function |
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| 194 | if ( *ubxSp == VALID ) ubxstate = UBXSTATE_IDLE; |
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| 195 | else // data invalid or allready processd |
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| 196 | { |
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| 197 | *ubxSp = INVALID; |
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| 198 | ubxstate = UBXSTATE_DATA; |
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| 199 | } |
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| 200 | break; |
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| 201 | |||
| 202 | case UBXSTATE_DATA: |
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| 203 | if (ubxP < ubxEp) *ubxP++ = c; // copy curent data byte if any space is left |
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| 204 | cka += c; |
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| 205 | ckb += cka; |
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| 206 | if (--msglen == 0) ubxstate = UBXSTATE_CKA; // switch to next state if all data was read |
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| 207 | break; |
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| 208 | |||
| 209 | case UBXSTATE_CKA: |
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| 210 | if (c == cka) ubxstate = UBXSTATE_CKB; |
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| 722 | killagreg | 211 | else |
| 212 | { |
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| 213 | *ubxSp = INVALID; |
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| 214 | ubxstate = UBXSTATE_IDLE; |
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| 215 | } |
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| 684 | killagreg | 216 | break; |
| 217 | |||
| 218 | case UBXSTATE_CKB: |
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| 219 | if (c == ckb) |
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| 220 | { |
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| 722 | killagreg | 221 | *ubxSp = VALID; // new data are valid |
| 222 | ROT_FLASH; |
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| 684 | killagreg | 223 | UpdateGPSInfo(); //update GPS info respectively |
| 224 | } |
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| 722 | killagreg | 225 | else |
| 226 | { // if checksum not fit then set data invalid |
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| 227 | *ubxSp = INVALID; |
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| 228 | } |
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| 684 | killagreg | 229 | ubxstate = UBXSTATE_IDLE; // ready to parse new data |
| 230 | break; |
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| 231 | |||
| 232 | default: // unknown ubx state |
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| 233 | ubxstate = UBXSTATE_IDLE; |
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| 234 | break; |
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| 235 | } |
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| 236 | |||
| 237 | } |
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| 238 |