Subversion Repositories FlightCtrl

Rev

Rev 2044 | Go to most recent revision | Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2039 - 1
#include <inttypes.h>
2
#include "ubx.h"
3
//#include "main.h"
4
#include <avr/io.h>
5
 
6
// ubx protocol parser state machine
7
#define UBXSTATE_IDLE   0
8
#define UBXSTATE_SYNC1  1
9
#define UBXSTATE_SYNC2  2
10
#define UBXSTATE_CLASS  3
11
#define UBXSTATE_LEN1   4
12
#define UBXSTATE_LEN2   5
13
#define UBXSTATE_DATA   6
14
#define UBXSTATE_CKA    7
15
#define UBXSTATE_CKB    8
16
 
17
// ublox protocoll identifier
18
#define UBX_CLASS_NAV   0x01
19
 
20
#define UBX_ID_POSLLH   0x02
21
#define UBX_ID_SOL              0x06
22
#define UBX_ID_VELNED   0x12
23
 
24
#define UBX_SYNC1_CHAR  0xB5
25
#define UBX_SYNC2_CHAR  0x62
26
 
27
typedef struct {
28
  uint32_t ITOW; // ms GPS Millisecond Time of Week
29
  int32_t Frac; // ns remainder of rounded ms above
30
  int16_t week; // GPS week
31
  uint8_t GPSfix; // GPSfix Type, range 0..6
32
  uint8_t Flags; // Navigation Status Flags
33
  int32_t ECEF_X; // cm ECEF X coordinate
34
  int32_t ECEF_Y; // cm ECEF Y coordinate
35
  int32_t ECEF_Z; // cm ECEF Z coordinate
36
  uint32_t PAcc; // cm 3D Position Accuracy Estimate
37
  int32_t ECEFVX; // cm/s ECEF X velocity
38
  int32_t ECEFVY; // cm/s ECEF Y velocity
39
  int32_t ECEFVZ; // cm/s ECEF Z velocity
40
  uint32_t SAcc; // cm/s Speed Accuracy Estimate
41
  uint16_t PDOP; // 0.01 Position DOP
42
  uint8_t res1; // reserved
43
  uint8_t numSV; // Number of SVs used in navigation solution
44
  uint32_t res2; // reserved
45
  Status_t Status;
46
} UBX_SOL_t;
47
 
48
typedef struct {
49
  uint32_t ITOW; // ms GPS Millisecond Time of Week
50
  int32_t LON; // 1e-07 deg Longitude
51
  int32_t LAT; // 1e-07 deg Latitude
52
  int32_t HEIGHT; // mm Height above Ellipsoid
53
  int32_t HMSL; // mm Height above mean sea level
54
  uint32_t Hacc; // mm Horizontal Accuracy Estimate
55
  uint32_t Vacc; // mm Vertical Accuracy Estimate
56
  Status_t Status;
57
} UBX_POSLLH_t;
58
 
59
typedef struct {
60
  uint32_t ITOW; // ms  GPS Millisecond Time of Week
61
  int32_t VEL_N; // cm/s  NED north velocity
62
  int32_t VEL_E; // cm/s  NED east velocity
63
  int32_t VEL_D; // cm/s  NED down velocity
64
  uint32_t Speed; // cm/s  Speed (3-D)
65
  uint32_t GSpeed; // cm/s  Ground Speed (2-D)
66
  int32_t Heading; // 1e-05 deg  Heading 2-D
67
  uint32_t SAcc; // cm/s  Speed Accuracy Estimate
68
  uint32_t CAcc; // deg  Course / Heading Accuracy Estimate
69
  Status_t Status;
70
} UBX_VELNED_t;
71
 
72
UBX_SOL_t UbxSol =
73
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, INVALID };
74
UBX_POSLLH_t UbxPosLlh = { 0, 0, 0, 0, 0, 0, 0, INVALID };
75
UBX_VELNED_t UbxVelNed = { 0, 0, 0, 0, 0, 0, 0, 0, 0, INVALID };
76
GPS_INFO_t GPSInfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, INVALID };
77
 
78
volatile uint8_t GPSTimeout = 0;
79
 
80
void updateGPSInfo(void) {
81
  if ((UbxSol.Status == NEWDATA) && (UbxPosLlh.Status == NEWDATA)
82
      && (UbxVelNed.Status == NEWDATA)) {
83
    //RED_FLASH;
84
    // DebugOut.Digital ....blah...
85
    if (GPSInfo.status != NEWDATA) {
86
      GPSInfo.status = INVALID;
87
      // NAV SOL
88
      GPSInfo.flags = UbxSol.Flags;
89
      GPSInfo.satfix = UbxSol.GPSfix;
90
      GPSInfo.satnum = UbxSol.numSV;
91
      GPSInfo.PAcc = UbxSol.PAcc;
92
      GPSInfo.VAcc = UbxSol.SAcc;
93
      // NAV POSLLH
94
      GPSInfo.longitude = UbxPosLlh.LON;
95
      GPSInfo.latitude = UbxPosLlh.LAT;
96
      GPSInfo.altitude = UbxPosLlh.HEIGHT;
97
 
98
      GPSInfo.veleast = UbxVelNed.VEL_E;
99
      GPSInfo.velnorth = UbxVelNed.VEL_N;
100
      GPSInfo.veltop = -UbxVelNed.VEL_D;
101
      GPSInfo.velground = UbxVelNed.GSpeed;
102
 
103
      GPSInfo.status = NEWDATA;
104
    }
105
 
106
    // set state to collect new data
107
    UbxSol.Status = PROCESSED; // never update old data
108
    UbxPosLlh.Status = PROCESSED; // never update old data
109
    UbxVelNed.Status = PROCESSED; // never update old data
110
  }
111
}
112
 
113
// this function should be called within the UART RX ISR
114
void ubx_parser(uint8_t c) {
115
  static uint8_t ubxstate = UBXSTATE_IDLE;
116
  static uint8_t cka, ckb;
117
  static uint16_t msglen;
118
  static int8_t *ubxP, *ubxEp, *ubxSp; // pointers to data currently transfered
119
 
120
  switch (ubxstate) {
121
  case UBXSTATE_IDLE: // check 1st sync byte
122
    if (c == UBX_SYNC1_CHAR)
123
      ubxstate = UBXSTATE_SYNC1;
124
    else
125
      ubxstate = UBXSTATE_IDLE; // out of synchronization
126
    break;
127
 
128
  case UBXSTATE_SYNC1: // check 2nd sync byte
129
    if (c == UBX_SYNC2_CHAR)
130
      ubxstate = UBXSTATE_SYNC2;
131
    else
132
      ubxstate = UBXSTATE_IDLE; // out of synchronization
133
    break;
134
 
135
  case UBXSTATE_SYNC2: // check msg class to be NAV
136
    if (c == UBX_CLASS_NAV)
137
      ubxstate = UBXSTATE_CLASS;
138
    else
139
      ubxstate = UBXSTATE_IDLE; // unsupported message class
140
    break;
141
 
142
  case UBXSTATE_CLASS: // check message identifier
143
    switch (c) {
144
    case UBX_ID_POSLLH: // geodetic position
145
      ubxP = (int8_t *) &UbxPosLlh; // data start pointer
146
      ubxEp = (int8_t *) (&UbxPosLlh + 1); // data end pointer
147
      ubxSp = (int8_t *) &UbxPosLlh.Status; // status pointer
148
      break;
149
 
150
    case UBX_ID_SOL: // navigation solution
151
      ubxP = (int8_t *) &UbxSol; // data start pointer
152
      ubxEp = (int8_t *) (&UbxSol + 1); // data end pointer
153
      ubxSp = (int8_t *) &UbxSol.Status; // status pointer
154
      break;
155
 
156
    case UBX_ID_VELNED: // velocity vector in tangent plane
157
      ubxP = (int8_t *) &UbxVelNed; // data start pointer
158
      ubxEp = (int8_t *) (&UbxVelNed + 1); // data end pointer
159
      ubxSp = (int8_t *) &UbxVelNed.Status; // status pointer
160
      break;
161
 
162
    default: // unsupported identifier
163
      ubxstate = UBXSTATE_IDLE;
164
      break;
165
    }
166
    if (ubxstate != UBXSTATE_IDLE) {
167
      ubxstate = UBXSTATE_LEN1;
168
      cka = UBX_CLASS_NAV + c;
169
      ckb = UBX_CLASS_NAV + cka;
170
    }
171
    break;
172
 
173
  case UBXSTATE_LEN1: // 1st message length byte
174
    msglen = c;
175
    cka += c;
176
    ckb += cka;
177
    ubxstate = UBXSTATE_LEN2;
178
    break;
179
 
180
  case UBXSTATE_LEN2: // 2nd message length byte
181
    msglen += ((uint16_t) c) << 8;
182
    cka += c;
183
    ckb += cka;
184
    // if the old data are not processed so far then break parsing now
185
    // to avoid writing new data in ISR during reading by another function
186
    if (*ubxSp == NEWDATA) {
187
      updateGPSInfo(); //update GPS info respectively
188
      ubxstate = UBXSTATE_IDLE;
189
    } else // data invalid or allready processd
190
    {
191
      *ubxSp = INVALID;
192
      ubxstate = UBXSTATE_DATA;
193
    }
194
    break;
195
 
196
  case UBXSTATE_DATA:
197
    if (ubxP < ubxEp)
198
      *ubxP++ = c; // copy curent data byte if any space is left
199
    cka += c;
200
    ckb += cka;
201
    if (--msglen == 0)
202
      ubxstate = UBXSTATE_CKA; // switch to next state if all data was read
203
    break;
204
 
205
  case UBXSTATE_CKA:
206
    if (c == cka)
207
      ubxstate = UBXSTATE_CKB;
208
    else {
209
      *ubxSp = INVALID;
210
      ubxstate = UBXSTATE_IDLE;
211
    }
212
    break;
213
 
214
  case UBXSTATE_CKB:
215
    if (c == ckb) {
216
      *ubxSp = NEWDATA; // new data are valid
217
      updateGPSInfo(); //update GPS info respectively
218
      GPSTimeout = 255;
219
    } else { // if checksum not match then set data invalid
220
      *ubxSp = INVALID;
221
    }
222
    ubxstate = UBXSTATE_IDLE; // ready to parse new data
223
    break;
224
 
225
  default: // unknown ubx state
226
    ubxstate = UBXSTATE_IDLE;
227
    break;
228
  }
229
}
230