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