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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 | |||
684 | killagreg | 8 | // ubx protocol parser state machine |
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 | #define UBX_ID_POSLLH 0x02 |
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22 | #define UBX_ID_POSUTM 0x08 |
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23 | #define UBX_ID_STATUS 0x03 |
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24 | #define UBX_ID_VELNED 0x12 |
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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 | uint8_t GPSfix; // GPSfix Type, range 0..6 |
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31 | uint8_t Flags; // Navigation Status Flags |
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32 | uint8_t DiffS; // Differential Status |
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33 | uint8_t res; // reserved |
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34 | uint32_t TTFF; // Time to first fix (millisecond time tag) |
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35 | uint32_t MSSS; // Milliseconds since Startup / Reset |
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702 | killagreg | 36 | uint8_t Status; |
684 | killagreg | 37 | } GPS_STATUS_t; |
38 | |||
39 | typedef struct { |
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40 | uint32_t ITOW; // ms GPS Millisecond Time of Week |
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41 | int32_t LON; // 1e-07 deg Longitude |
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42 | int32_t LAT; // 1e-07 deg Latitude |
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43 | int32_t HEIGHT; // mm Height above Ellipsoid |
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44 | int32_t HMSL; // mm Height above mean sea level |
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45 | uint32_t Hacc; // mm Horizontal Accuracy Estimate |
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46 | uint32_t Vacc; // mm Vertical Accuracy Estimate |
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702 | killagreg | 47 | uint8_t Status; |
684 | killagreg | 48 | } GPS_POSLLH_t; |
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 EAST; // cm UTM Easting |
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53 | int32_t NORTH; // cm UTM Nording |
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54 | int32_t ALT; // cm altitude |
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55 | uint8_t ZONE; // UTM zone number |
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56 | uint8_t HEM; // Hemisphere Indicator (0=North, 1=South) |
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702 | killagreg | 57 | uint8_t Status; |
684 | killagreg | 58 | } GPS_POSUTM_t; |
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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702 | killagreg | 70 | uint8_t Status; |
684 | killagreg | 71 | } GPS_VELNED_t; |
72 | |||
73 | |||
726 | killagreg | 74 | GPS_STATUS_t GpsStatus = {0,0,0,0,0,0,0, INVALID}; |
75 | GPS_POSLLH_t GpsPosLlh = {0,0,0,0,0,0,0, INVALID}; |
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76 | GPS_POSUTM_t GpsPosUtm = {0,0,0,0,0,0, INVALID}; |
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77 | GPS_VELNED_t GpsVelNed = {0,0,0,0,0,0,0,0,0, INVALID}; |
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78 | GPS_INFO_t GPSInfo = {0,0,0,0,0,0,0,0,0,0, INVALID}; |
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684 | killagreg | 79 | |
726 | killagreg | 80 | volatile uint8_t GPSTimeout = 0; |
684 | killagreg | 81 | |
82 | void UpdateGPSInfo (void) |
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83 | { |
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702 | killagreg | 84 | if (GpsStatus.Status == VALID) // valid packet |
684 | killagreg | 85 | { |
702 | killagreg | 86 | GPSInfo.satfix = GpsStatus.GPSfix; |
726 | killagreg | 87 | GpsStatus.Status = PROCESSED; // never update old data |
684 | killagreg | 88 | } |
702 | killagreg | 89 | if (GpsPosLlh.Status == VALID) // valid packet |
684 | killagreg | 90 | { |
702 | killagreg | 91 | GPSInfo.longitude = GpsPosLlh.LON; |
92 | GPSInfo.latitude = GpsPosLlh.LAT; |
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93 | GPSInfo.altitude = GpsPosLlh.HEIGHT; |
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726 | killagreg | 94 | GpsPosLlh.Status = PROCESSED; // never update old data |
684 | killagreg | 95 | } |
702 | killagreg | 96 | if (GpsPosUtm.Status == VALID) // valid packet |
684 | killagreg | 97 | { |
702 | killagreg | 98 | GPSInfo.utmeast = GpsPosUtm.EAST; |
99 | GPSInfo.utmnorth = GpsPosUtm.NORTH; |
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100 | GPSInfo.utmalt = GpsPosUtm.ALT; |
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726 | killagreg | 101 | GpsPosUtm.Status = PROCESSED; // never update old data |
684 | killagreg | 102 | } |
702 | killagreg | 103 | if (GpsVelNed.Status == VALID) // valid packet |
684 | killagreg | 104 | { |
702 | killagreg | 105 | GPSInfo.veleast = GpsVelNed.VEL_E; |
106 | GPSInfo.velnorth = GpsVelNed.VEL_N; |
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107 | GPSInfo.veltop = -GpsVelNed.VEL_D; |
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726 | killagreg | 108 | GpsVelNed.Status = PROCESSED; // never update old data |
684 | killagreg | 109 | } |
722 | killagreg | 110 | if (GpsStatus.Status != INVALID) |
702 | killagreg | 111 | { |
726 | killagreg | 112 | GPSInfo.status = VALID; // set valid if data are updated |
702 | killagreg | 113 | } |
684 | killagreg | 114 | } |
115 | |||
724 | killagreg | 116 | |
684 | killagreg | 117 | // this function should be called within the UART RX ISR |
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 |
726 | killagreg | 224 | GPSTimeout = 255; |
684 | killagreg | 225 | } |
722 | killagreg | 226 | else |
227 | { // if checksum not fit then set data invalid |
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228 | *ubxSp = INVALID; |
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229 | } |
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684 | killagreg | 230 | ubxstate = UBXSTATE_IDLE; // ready to parse new data |
231 | break; |
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232 | |||
233 | default: // unknown ubx state |
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234 | ubxstate = UBXSTATE_IDLE; |
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235 | break; |
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236 | } |
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237 | |||
238 | } |
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239 | |||
724 | killagreg | 240 |