Weather Station using an mBed microcontroller and a Windows CE Device
Dependencies: TextLCD mbed HMC6352
Diff: GPS.cpp
- Revision:
- 0:75e6a2e50519
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/GPS.cpp Thu Dec 15 13:38:51 2011 +0000 @@ -0,0 +1,170 @@ +/* mbed EM-406 GPS Module Library + * Copyright (c) 2008-2010, sford + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "GPS.h" + + +GPS::GPS(PinName tx, PinName rx) : _gps(tx, rx) { + _gps.baud(4800); + longitude = 0.0; + latitude = 0.0; +} + +int GPS::sample() { + float time2, time, date; + float latitude2, longitude2, speed, course, magneticVar; + char ns, ew, ns2, ew2, mgEW, mode, status; + + + //return 1; //testing by Jigar + while (1) { + getline(); + //printf("\n\rentered the GPS.sample while loop \n\r %s\n\r", msg); + + + // Check if it is a GPGGA msg (matches both locked and non-locked msg) + // $GPGGA,000116.031,,,,,0,00,,,M,0.0,M,,0000*52 + /* + eg3. $GPGGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh + 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 + 1 = UTC of Position + 2 = Latitude + 3 = N or S + 4 = Longitude + 5 = E or W + 6 = GPS quality indicator (0=invalid; 1=GPS fix; 2=Diff. GPS fix) + 7 = Number of satellites in use [not those in view] + 8 = Horizontal dilution of position + 9 = Antenna altitude above/below mean sea level (geoid) + 10 = Meters (Antenna height unit) + 11 = Geoidal separation (Diff. between WGS-84 earth ellipsoid and + mean sea level. -=geoid is below WGS-84 ellipsoid) + 12 = Meters (Units of geoidal separation) + 13 = Age in seconds since last update from diff. reference station + 14 = Diff. reference station ID# + 15 = Checksum + + */ + // if (sscanf(msg, "GPGGA,%f,%f,%c,%f,%c,%*d,%*d, %*f,%*f,%*f,%*f,%*f,%*f,%d ", &time, &latitude, &ns, &longitude, &ew, &lock, &numSat, &horDil, &altitude) >= 1) { + if(sscanf(msg, "GPGGA,%f,%f,%c,%f,%c,%d,%d,%f,%f", &time2, &latitude, &ns, &longitude, &ew, &lock, &numSat, &horDil, &altitude) >= 1) { + + if (!lock) { + longitude = 0.0; + latitude = 0.0; + return 0; + } else { + if (ns == 'S') { + latitude *= -1.0; + } + if (ew == 'W') { + longitude *= -1.0; + } + float degrees = trunc(latitude / 100.0f); + float minutes = latitude - (degrees * 100.0f); + latitude = degrees + minutes / 60.0f; + degrees = trunc(longitude / 100.0f ); //degrees = trunc(longitude / 100.0f * 0.01f); + minutes = longitude - (degrees * 100.0f); + longitude = degrees + minutes / 60.0f; + return 1; + } + } + + // Check if it is a GPRMC msg (matches both locked and non-locked msg) + /* + $GPRMC,hhmmss.ss,a,llll.ll,N,llll.ll,E,x.x,x.x,ddmmyy,x.x,E,A*hh + 1 2 3 4 5 6 7 8 9 10 11 12 13 + 1 = UTC of Position + 2 = Status + 3 = Latitude + 4 = N or S + 5 = Longitude + 6 = E or W + 7 = Speed Over Ground (knots) + 8 = Course Over Ground (degrees) + 9 = Date (ddmmyy) + 10 = Magnetic Variation (degrees) + 11 = E or W (for magnetic variation) + 12 = Mode (A = Autonomous, D = DGPS, E = DR) + 13 = Checksum + + */ + // $GPRMC,161229.487,A,3723.2475,N,12158.3416,W,0.13,309.62,120598, ,*10 + if(sscanf(msg, "GPRMC,%f,%c,%f,%c,%f,%c,%f,%f,%f,%f,%c,%c", &time, &status, &latitude2, &ns2, &longitude2, &ew2, &speed, &course, &date, &magneticVar, &mgEW, &mode) >= 1) { + + // CONVERT TO STRING AND FORMAT TIME AND DATE + + GPStime = time; + GPSdate = date; + + } + + + } +} + +float GPS::trunc(float v) { + if (v < 0.0) { + v*= -1.0; + v = floor(v); + v*=-1.0; + } else { + v = floor(v); + } + return v; +} + +void GPS::getline() { + + while (_gps.getc() != '$'); // wait for the start of a line + // printf("entered the getline loop\n\r"); + for (int i=0; i<256; i++) { + msg[i] = _gps.getc(); + if (msg[i] == '\r') { + msg[i] = 0; + return; + } + } + error("Overflowed message limit"); +} + +/* +$GPRMC,000115.039,V,,,,,,,291006,,*2C +$GPGGA,000116.031,,,,,0,00,,,M,0.0,M,,0000*52 +$GPGSA,A,1,,,,,,,,,,,,,,,*1E +$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C +$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76 +$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78 +$GPRMC,000116.031,V,,,,,,,291006,,*27 +$GPGGA,000117.035,,,,,0,00,,,M,0.0,M,,0000*57 +$GPGSA,A,1,,,,,,,,,,,,,,,*1E +$GPRMC,000117.035,V,,,,,,,291006,,*22 +$GPGGA,000118.039,,,,,0,00,,,M,0.0,M,,0000*54 +$GPGSA,A,1,,,,,,,,,,,,,,,*1E +$GPRMC,000118.039,V,,,,,,,291006,,*21 +$GPGGA,000119.035,,,,,0,00,,,M,0.0,M,,0000*59 +$GPGSA,A,1,,,,,,,,,,,,,,,*1E +$GPRMC,000119.035,V,,,,,,,291006,,*2C +$GPGGA,000120.037,,,,,0,00,,,M,0.0,M,,0000*51 +$GPGSA,A,1,,,,,,,,,,,,,,,*1E +$GPRMC,000120.037,V,,,,,,,291006,,*24 + +*/ \ No newline at end of file