usen usen / MODGPS

Allows for a GPS module to be connected to a serial port and exposes an easy to use API to get the GPS data. New feature, added Mbed/LPC17xx RTC synchronisation

Fork of MODGPS by Andy K

GPS.cpp@5:7f130f85d5a4, 2011-04-20 (annotated)

Committer:
AjK
Date:
Wed Apr 20 09:15:07 2011 +0000
Revision:
5:7f130f85d5a4
Parent:
3:28a1b60b0f37
Child:
6:64771e31464e
1.15 See ChangeLog.c

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AjK 0:db98027c0bbb 1 /*
AjK 0:db98027c0bbb 2 Copyright (c) 2010 Andy Kirkham
AjK 0:db98027c0bbb 3
AjK 0:db98027c0bbb 4 Permission is hereby granted, free of charge, to any person obtaining a copy
AjK 0:db98027c0bbb 5 of this software and associated documentation files (the "Software"), to deal
AjK 0:db98027c0bbb 6 in the Software without restriction, including without limitation the rights
AjK 0:db98027c0bbb 7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
AjK 0:db98027c0bbb 8 copies of the Software, and to permit persons to whom the Software is
AjK 0:db98027c0bbb 9 furnished to do so, subject to the following conditions:
AjK 0:db98027c0bbb 10
AjK 0:db98027c0bbb 11 The above copyright notice and this permission notice shall be included in
AjK 0:db98027c0bbb 12 all copies or substantial portions of the Software.
AjK 0:db98027c0bbb 13
AjK 0:db98027c0bbb 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
AjK 0:db98027c0bbb 15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
AjK 0:db98027c0bbb 16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AjK 0:db98027c0bbb 17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
AjK 0:db98027c0bbb 18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
AjK 0:db98027c0bbb 19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
AjK 0:db98027c0bbb 20 THE SOFTWARE.
AjK 0:db98027c0bbb 21 */
AjK 0:db98027c0bbb 22
AjK 0:db98027c0bbb 23 #include "GPS.h"
AjK 0:db98027c0bbb 24
AjK 0:db98027c0bbb 25 GPS::GPS(PinName tx, PinName rx, const char *name) : Serial(tx, rx, name)
AjK 0:db98027c0bbb 26 {
AjK 3:28a1b60b0f37 27 _nmeaOnUart0 = false;
AjK 3:28a1b60b0f37 28
AjK 3:28a1b60b0f37 29 _lastByte = 0;
AjK 3:28a1b60b0f37 30
AjK 0:db98027c0bbb 31 switch(_uidx) {
AjK 0:db98027c0bbb 32 case 1: _base = LPC_UART1; break;
AjK 0:db98027c0bbb 33 case 2: _base = LPC_UART2; break;
AjK 0:db98027c0bbb 34 case 3: _base = LPC_UART3; break;
AjK 0:db98027c0bbb 35 default : _base = NULL; break;
AjK 0:db98027c0bbb 36 }
AjK 0:db98027c0bbb 37
AjK 0:db98027c0bbb 38 _pps = NULL;
AjK 0:db98027c0bbb 39 _ppsInUse = false;
AjK 0:db98027c0bbb 40
AjK 0:db98027c0bbb 41 if (_base != NULL) attach(this, &GPS::rx_irq);
AjK 0:db98027c0bbb 42
AjK 0:db98027c0bbb 43 _second100 = new Ticker;
AjK 0:db98027c0bbb 44 _second100->attach_us(this, &GPS::ticktock, GPS_TICKTOCK);
AjK 0:db98027c0bbb 45 }
AjK 0:db98027c0bbb 46
AjK 0:db98027c0bbb 47 void
AjK 0:db98027c0bbb 48 GPS::ppsAttach(PinName irq, ppsEdgeType type)
AjK 0:db98027c0bbb 49 {
AjK 0:db98027c0bbb 50 if (_pps != NULL) delete(_pps);
AjK 0:db98027c0bbb 51 _pps = new InterruptIn(irq);
AjK 0:db98027c0bbb 52 if (type == ppsRise) _pps->rise(this, &GPS::pps_irq);
AjK 0:db98027c0bbb 53 else _pps->fall(this, &GPS::pps_irq);
AjK 0:db98027c0bbb 54 _ppsInUse = true;
AjK 0:db98027c0bbb 55 }
AjK 0:db98027c0bbb 56
AjK 0:db98027c0bbb 57 void
AjK 0:db98027c0bbb 58 GPS::ppsUnattach(void)
AjK 0:db98027c0bbb 59 {
AjK 0:db98027c0bbb 60 if (_pps != NULL) delete(_pps);
AjK 0:db98027c0bbb 61 _ppsInUse = false;
AjK 0:db98027c0bbb 62 }
AjK 0:db98027c0bbb 63
AjK 0:db98027c0bbb 64 double
AjK 0:db98027c0bbb 65 GPS::latitude(void)
AjK 0:db98027c0bbb 66 {
AjK 0:db98027c0bbb 67 double a, b;
AjK 0:db98027c0bbb 68 do { a = thePlace.lat; b = thePlace.lat; } while (a != b);
AjK 0:db98027c0bbb 69 return a;
AjK 0:db98027c0bbb 70 }
AjK 0:db98027c0bbb 71
AjK 0:db98027c0bbb 72 double
AjK 0:db98027c0bbb 73 GPS::longitude(void)
AjK 0:db98027c0bbb 74 {
AjK 0:db98027c0bbb 75 double a, b;
AjK 0:db98027c0bbb 76 do { a = thePlace.lon; b = thePlace.lon; } while (a != b);
AjK 0:db98027c0bbb 77 return a;
AjK 0:db98027c0bbb 78 }
AjK 0:db98027c0bbb 79
AjK 0:db98027c0bbb 80 double
AjK 0:db98027c0bbb 81 GPS::altitude(void)
AjK 0:db98027c0bbb 82 {
AjK 0:db98027c0bbb 83 double a, b;
AjK 0:db98027c0bbb 84 do { a = thePlace.alt; b = thePlace.alt; } while (a != b);
AjK 0:db98027c0bbb 85 return a;
AjK 0:db98027c0bbb 86 }
AjK 0:db98027c0bbb 87
AjK 0:db98027c0bbb 88 GPS_Geodetic *
AjK 0:db98027c0bbb 89 GPS::geodetic(GPS_Geodetic *q)
AjK 0:db98027c0bbb 90 {
AjK 3:28a1b60b0f37 91 GPS_Geodetic a;
AjK 0:db98027c0bbb 92
AjK 0:db98027c0bbb 93 if (q == NULL) q = new GPS_Geodetic;
AjK 0:db98027c0bbb 94
AjK 0:db98027c0bbb 95 do {
AjK 0:db98027c0bbb 96 memcpy(&a, &thePlace, sizeof(GPS_Geodetic));
AjK 3:28a1b60b0f37 97 memcpy(q, &thePlace, sizeof(GPS_Geodetic));
AjK 0:db98027c0bbb 98 }
AjK 3:28a1b60b0f37 99 while (memcmp(&a, q, sizeof(GPS_Geodetic)) != 0);
AjK 0:db98027c0bbb 100
AjK 0:db98027c0bbb 101 return q;
AjK 0:db98027c0bbb 102 }
AjK 0:db98027c0bbb 103
AjK 2:8aa059e7d8b1 104 GPS_VTG *
AjK 2:8aa059e7d8b1 105 GPS::vtg(GPS_VTG *q)
AjK 2:8aa059e7d8b1 106 {
AjK 3:28a1b60b0f37 107 GPS_VTG a;
AjK 2:8aa059e7d8b1 108
AjK 2:8aa059e7d8b1 109 if (q == NULL) q = new GPS_VTG;
AjK 2:8aa059e7d8b1 110
AjK 2:8aa059e7d8b1 111 do {
AjK 2:8aa059e7d8b1 112 memcpy(&a, &theVTG, sizeof(GPS_VTG));
AjK 3:28a1b60b0f37 113 memcpy(q, &theVTG, sizeof(GPS_VTG));
AjK 2:8aa059e7d8b1 114 }
AjK 3:28a1b60b0f37 115 while (memcmp(&a, q, sizeof(GPS_VTG)) != 0);
AjK 2:8aa059e7d8b1 116
AjK 2:8aa059e7d8b1 117 return q;
AjK 2:8aa059e7d8b1 118 }
AjK 2:8aa059e7d8b1 119
AjK 0:db98027c0bbb 120 void
AjK 0:db98027c0bbb 121 GPS::ticktock(void)
AjK 0:db98027c0bbb 122 {
AjK 0:db98027c0bbb 123 // Increment the time structure by 1/100th of a second.
AjK 0:db98027c0bbb 124 ++theTime;
AjK 0:db98027c0bbb 125
AjK 0:db98027c0bbb 126 // Test the serial queue.
AjK 0:db98027c0bbb 127 if (process_required) {
AjK 0:db98027c0bbb 128 char *s = buffer[active_buffer == 0 ? 1 : 0];
AjK 0:db98027c0bbb 129 if (!strncmp(s, "$GPRMC", 6)) {
AjK 0:db98027c0bbb 130 theTime.nmea_rmc(s);
AjK 0:db98027c0bbb 131 cb_rmc.call();
AjK 0:db98027c0bbb 132 if (!_ppsInUse) theTime.fractionalReset();
AjK 0:db98027c0bbb 133 }
AjK 0:db98027c0bbb 134 else if (!strncmp(s, "$GPGGA", 6)) {
AjK 0:db98027c0bbb 135 thePlace.nmea_gga(s);
AjK 0:db98027c0bbb 136 cb_gga.call();
AjK 0:db98027c0bbb 137 }
AjK 2:8aa059e7d8b1 138 else if (!strncmp(s, "$GPVTG", 6)) {
AjK 2:8aa059e7d8b1 139 theVTG.nmea_vtg(s);
AjK 2:8aa059e7d8b1 140 cb_vtg.call();
AjK 2:8aa059e7d8b1 141 }
AjK 0:db98027c0bbb 142 process_required = false;
AjK 0:db98027c0bbb 143 }
AjK 5:7f130f85d5a4 144
AjK 5:7f130f85d5a4 145 // If we have a valid GPS time then, once per minute, set the RTC.
AjK 5:7f130f85d5a4 146 if (theTime.status == 'A' && theTime.second == 0 && theTime.tenths == 0 && theTime.hundreths == 0) {
AjK 5:7f130f85d5a4 147 // set_time() is defined in rtc_time.h
AjK 5:7f130f85d5a4 148 // http://mbed.org/projects/libraries/svn/mbed/trunk/rtc_time.h
AjK 5:7f130f85d5a4 149 set_time(theTime.to_C_tm());
AjK 5:7f130f85d5a4 150 }
AjK 5:7f130f85d5a4 151
AjK 0:db98027c0bbb 152 }
AjK 0:db98027c0bbb 153
AjK 0:db98027c0bbb 154 void
AjK 0:db98027c0bbb 155 GPS::pps_irq(void)
AjK 0:db98027c0bbb 156 {
AjK 0:db98027c0bbb 157 theTime.fractionalReset();
AjK 0:db98027c0bbb 158 theTime++; // Increment the time/date by one second.
AjK 0:db98027c0bbb 159 cb_pps.call();
AjK 0:db98027c0bbb 160 }
AjK 2:8aa059e7d8b1 161
AjK 0:db98027c0bbb 162 void
AjK 0:db98027c0bbb 163 GPS::rx_irq(void)
AjK 0:db98027c0bbb 164 {
AjK 0:db98027c0bbb 165 uint32_t iir __attribute__((unused));
AjK 0:db98027c0bbb 166 char c;
AjK 0:db98027c0bbb 167
AjK 0:db98027c0bbb 168 if (_base) {
AjK 0:db98027c0bbb 169 iir = (uint32_t)*((char *)_base + GPS_IIR);
AjK 0:db98027c0bbb 170 while((int)(*((char *)_base + GPS_LSR) & 0x1)) {
AjK 3:28a1b60b0f37 171 c = (char)(*((char *)_base + GPS_RBR) & 0xFF);
AjK 3:28a1b60b0f37 172
AjK 3:28a1b60b0f37 173 // strtok workaround.
AjK 3:28a1b60b0f37 174 // Found that ,, together (which some NMEA sentences
AjK 3:28a1b60b0f37 175 // contain for a null/empty field) confuses strtok()
AjK 3:28a1b60b0f37 176 // function. Solution:- Push a "zero" into the string
AjK 3:28a1b60b0f37 177 // for missing/empty fields.
AjK 3:28a1b60b0f37 178 if (c == ',' && _lastByte == ',') {
AjK 3:28a1b60b0f37 179 buffer[active_buffer][rx_buffer_in] = '0';
AjK 3:28a1b60b0f37 180 if (++rx_buffer_in >= GPS_BUFFER_LEN) rx_buffer_in = 0;
AjK 3:28a1b60b0f37 181 }
AjK 3:28a1b60b0f37 182
AjK 3:28a1b60b0f37 183 // Debugging/dumping data.
AjK 3:28a1b60b0f37 184 if (_nmeaOnUart0) LPC_UART0->RBR = c;
AjK 3:28a1b60b0f37 185
AjK 3:28a1b60b0f37 186 // Put the byte into the string.
AjK 3:28a1b60b0f37 187 buffer[active_buffer][rx_buffer_in] = c;
AjK 3:28a1b60b0f37 188 if (++rx_buffer_in >= GPS_BUFFER_LEN) rx_buffer_in = 0;
AjK 3:28a1b60b0f37 189
AjK 3:28a1b60b0f37 190 // Save for next time an irq occurs. See strtok() above.
AjK 3:28a1b60b0f37 191 _lastByte = c;
AjK 3:28a1b60b0f37 192
AjK 3:28a1b60b0f37 193 // If end of NMEA sentence flag for processing.
AjK 0:db98027c0bbb 194 if (c == '\n') {
AjK 0:db98027c0bbb 195 active_buffer = active_buffer == 0 ? 1 : 0;
AjK 0:db98027c0bbb 196 process_required = true;
AjK 0:db98027c0bbb 197 rx_buffer_in = 0;
AjK 3:28a1b60b0f37 198 }
AjK 0:db98027c0bbb 199 }
AjK 0:db98027c0bbb 200 }
AjK 0:db98027c0bbb 201 }