David Spillman
Updated version with new commands and sleep mode
Fork of
GPS
by 
Sam Clarke
Revision 7:7aac669b0075, committed 2015-04-07
- Comitter:
- Spilly
- Date:
- Tue Apr 07 03:49:28 2015 +0000
- Parent:
- 6:af055728e564
- Child:
- 8:2476bea153a1
- Commit message:
- Added additional documentation/comments
Changed in this revision
| GPS.cpp | Show annotated file Show diff for this revision Revisions of this file |
| GPS.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/GPS.cpp Sun Apr 05 01:41:34 2015 +0000
+++ b/GPS.cpp Tue Apr 07 03:49:28 2015 +0000
@@ -2,10 +2,15 @@
// This is a modified version of mbed /users/SamClarke/code/GPS/ for MTK3339 GPS module
//
// Changes made by Ryan Spillman:
+//
+// Last updated: 4/6/2015
+//
// added commands to the initialization function to set baud rate, set update rate, enabled DGPS WAAS, and set minimum navigation speed
// added a function to put the unit into sleep mode
// added several zeros after the decimal places to fix weird rounding errors
// added information about checksums
+// Modified parse data function to get all of the NMEA sentences at once. Previously it only grabbed one sentence each time the function was called
+// Changed latitude and longitude calculation variables to doubles to decrease math errors
//
// IMPORTANT:
// Any changes made to commands sent to GPS unit require corresponding changes to the
@@ -14,6 +19,8 @@
// http://siliconsparrow.com/demos/nmeachecksum.php
**************************************************************************************************************************************************************/
+//GDOP = delta(output location) / delta(measured data)
+
#include "GPS.h"
GPS::GPS(PinName tx, PinName rx) : _UltimateGps(tx, rx)
{
@@ -21,86 +28,188 @@
_UltimateGps.baud(38400); //Changed firmware of MTK3339 to 38400 baud with update rate of 5Hz (GlobalTopFlashTool to change firmware)
}
+void GPS::coldStart()
+{
+ _UltimateGps.printf("$PMTK103*30\r\n");
+}
+int GPS::getGPGGA()
+{
+ if(sscanf(NEMA, "GPGGA, %*f, %*f, %*c, %*f, %*c, %d, %d, %*f, %f", &fixtype, &satellites, &altitude) >=1)
+ {
+ //if(fixtype == 0) return 0;
+ return 1;
+ }
+ return 0;
+}
+int GPS::getGPGSA()
+{
+ if(satellites == 4)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*c, %*c, %*c, %*c,,,,,,,,,%f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 5)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d,,,,,,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 6)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d,,,,,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 7)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d,,,,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 8)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d,,,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 9)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d,,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 10)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d,,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else if(satellites == 11)
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d,, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ else
+ {
+ if(sscanf(NEMA, "GPGSA, %c, %d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %*d, %f, %f, %f", &mode, &status, &PDOP, &HDOP, &VDOP) >=1) return 1;
+ }
+ return 0;
+}
+int GPS::getGPRMC()
+{
+
+ if(sscanf(NEMA, "GPRMC, %2d%2d%f, %c, %f, %c, %f, %c, %f, %f, %2d%2d%2d", &hours, &minutes, &seconds, &validity, &latitude, &ns, &longitude, &ew, &speed, &heading, &day, &month, &year) >=1)
+ {
+ year += 2000;
+ if(ns =='S') {
+ latitude *= -1.00000000000000000f;
+ }
+ if(ew =='W') {
+ longitude *= -1.00000000000000000f;
+ }
+ double degrees = trunc(latitude / 100.0000000000000000f);
+ double minutes = latitude - (degrees * 100.00000000000000000f);
+ degLat = degrees + minutes / 60.00000000000000000f;
+ degrees = trunc(longitude / 100.0000000000000000f);
+ minutes = longitude - (degrees * 100.00000000000000000f);
+ degLon = degrees + minutes / 60.00000000000000000f;
+ if(fixtype == 1) {
+ fix = "Positive";
+ }
+ if(fixtype == 2) {
+ fix = "Differential";
+ }
+ if(heading > 0.00f && heading < 45.00f) {
+ cardinal = "NNE";
+ }
+ if(heading == 45.00f) {
+ cardinal = "NE";
+ }
+ if(heading > 45.00f && heading < 90.00f) {
+ cardinal = "ENE";
+ }
+ if(heading == 90.00f) {
+ cardinal = "E";
+ }
+ if(heading > 90.00f && heading < 135.00f) {
+ cardinal = "ESE";
+ }
+ if(heading == 135.00f) {
+ cardinal = "SE";
+ }
+ if(heading > 135.00f && heading < 180.00f) {
+ cardinal = "SSE";
+ }
+ if(heading == 180.00f) {
+ cardinal = "S";
+ }
+ if(heading > 180.00f && heading < 225.00f) {
+ cardinal = "SSW";
+ }
+ if(heading == 225.00f) {
+ cardinal = "SW";
+ }
+ if(heading > 225.00f && heading < 270.00f) {
+ cardinal = "WSW";
+ }
+ if(heading == 270.00f) {
+ cardinal = "W";
+ }
+ if(heading > 270.00f && heading < 315.00f) {
+ cardinal = "WNW";
+ }
+ if(heading == 315.00f) {
+ cardinal = "NW";
+ }
+ if(heading > 315.00f && heading < 360.00f) {
+ cardinal = "NNW";
+ }
+ if(heading == 360.00f || heading == 0.00f) {
+ cardinal = "N";
+ }
+ kph = speed*1.852f;
+ return 1;
+ }
+ return 0;
+}
int GPS::parseData()
{
- while(1) {
+ getData();
+ if(getGPGGA())
+ {
getData();
- if(sscanf(NEMA, "GPGGA, %*f, %*f, %*c, %*f, %*c, %d, %d, %*f, %f", &fixtype, &satellites, &altitude) >=1);
- if(sscanf(NEMA, "GPRMC, %2d%2d%f, %c, %f, %c, %f, %c, %f, %f, %2d%2d%2d", &hours, &minutes, &seconds, &validity, &latitude, &ns, &longitude, &ew, &speed, &heading, &day, &month, &year) >=1) {
- if(fixtype == 0) {
- return 0;
- }
- year += 2000;
- if(ns =='S') {
- latitude *= -1.00000000000000000f;
- }
- if(ew =='W') {
- longitude *= -1.00000000000000000f;
- }
- float degrees = trunc(latitude / 100.0000000000000000f);
- float minutes = latitude - (degrees * 100.00000000000000000f);
- latitude = degrees + minutes / 60.00000000000000000f;
- degrees = trunc(longitude / 100.0000000000000000f);
- minutes = longitude - (degrees * 100.00000000000000000f);
- longitude = degrees + minutes / 60.00000000000000000f;
- if(fixtype == 1) {
- fix = "Positive";
- }
- if(fixtype == 2) {
- fix = "Differential";
- }
- if(heading > 0.00f && heading < 45.00f) {
- cardinal = "NNE";
- }
- if(heading == 45.00f) {
- cardinal = "NE";
- }
- if(heading > 45.00f && heading < 90.00f) {
- cardinal = "ENE";
- }
- if(heading == 90.00f) {
- cardinal = "E";
- }
- if(heading > 90.00f && heading < 135.00f) {
- cardinal = "ESE";
- }
- if(heading == 135.00f) {
- cardinal = "SE";
- }
- if(heading > 135.00f && heading < 180.00f) {
- cardinal = "SSE";
- }
- if(heading == 180.00f) {
- cardinal = "S";
- }
- if(heading > 180.00f && heading < 225.00f) {
- cardinal = "SSW";
- }
- if(heading == 225.00f) {
- cardinal = "SW";
- }
- if(heading > 225.00f && heading < 270.00f) {
- cardinal = "WSW";
- }
- if(heading == 270.00f) {
- cardinal = "W";
- }
- if(heading > 270.00f && heading < 315.00f) {
- cardinal = "WNW";
- }
- if(heading == 315.00f) {
- cardinal = "NW";
- }
- if(heading > 315.00f && heading < 360.00f) {
- cardinal = "NNW";
- }
- if(heading == 360.00f || heading == 0.00f) {
- cardinal = "N";
- }
- kph = speed*1.852f;
+ if(getGPGSA())
+ {
+ getData();
+ getGPRMC();
+ return 1;
+ }
+ else
+ {
+ getData();
+ getGPGSA();
return 1;
}
}
+ else if(getGPGSA())
+ {
+ getData();
+ if(getGPGGA())
+ {
+ getData();
+ getGPRMC();
+ return 1;
+ }
+ else
+ {
+ getData();
+ getGPGGA();
+ return 1;
+ }
+ }
+ else
+ {
+ getData();
+ if(getGPGGA())
+ {
+ getData();
+ getGPGSA();
+ return 1;
+ }
+ else if(getGPGSA())
+ {
+ getData();
+ getGPGGA();
+ return 1;
+ }
+ }
+ return 0;
}
@@ -131,13 +240,24 @@
void GPS::Init()
{
- _UltimateGps.printf("$PMTK251,38400*27\r\n"); //set baud (any higher and the serial buffer overflows)
- //_UltimateGps.printf("$PMTK220,100*2F\r\n"); //10 Hz update
- _UltimateGps.printf("$PMTK220,200*2C\r\n"); //5 Hz udpate
- _UltimateGps.printf("$PMTK225,0*2bt\r\n"); //disable always locate (datasheet indicates that this negatively affects accuracy)
- _UltimateGps.printf("$PMTK301,2*2et\r\n"); //set DGPS to use WAAS
- _UltimateGps.printf("$PMTK386,0.8*35\r\n"); //set Nav Speed threshold to 0.8 m/s
- _UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n");
+ //don't need to send baud rate command because it is already set to 38400 in firmware
+ //_UltimateGps.printf("$PMTK251,38400*27\r\n"); //set baud (any higher and the serial buffer overflows)
+
+ //Note: SBAS can only be enabled when update rate is less than or equal to 5Hz.
+ //_UltimateGps.printf("$PMTK220,100*2F\r\n"); //10 Hz update
+ _UltimateGps.printf("$PMTK220,200*2C\r\n"); //5 Hz udpate
+ //_UltimateGps.printf("$PMTK220,1000*1f\r\n"); //1 Hz udpate
+
+ _UltimateGps.printf("$PMTK225,0*2bt\r\n"); //disable always locate (datasheet indicates that this negatively affects accuracy)
+ _UltimateGps.printf("$PMTK301,2*2et\r\n"); //set DGPS to use WAAS
+
+ //_UltimateGps.printf("$PMTK386,0.8*35\r\n"); //set Nav Speed threshold to 0.8 m/s
+ //_UltimateGps.printf("$PMTK386,0.2*3f\r\n"); //set Nav Speed threshold to 0.2 m/s
+ _UltimateGps.printf("$PMTK386,0*23\r\n"); //disable Nav Speed threshold
+
+ //_UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"); //GPRMC and GPGGA
+ //_UltimateGps.printf("$PMTK314,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"); //GPRMC and GPGSA
+ _UltimateGps.printf("$PMTK314,0,1,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n"); //GPRMC, GPGGA, and GPGSA
}
void GPS::Sleep(int sleep)
@@ -148,8 +268,24 @@
}
else
{
- _UltimateGps.printf("$$PMTK161,1*28\r\n"); //wake up
- _UltimateGps.printf("$PMTK220,200*2C\r\n"); //5 Hz udpate
- _UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n");
+ _UltimateGps.printf("$$PMTK161,1*28\r\n"); //wake up
+
+ /*unit goes back to default config when put to sleep*/
+
+ //Note: SBAS can only be enabled when update rate is less than or equal to 5Hz.
+ //_UltimateGps.printf("$PMTK220,100*2F\r\n"); //10 Hz update
+ _UltimateGps.printf("$PMTK220,200*2C\r\n"); //5 Hz udpate
+ //_UltimateGps.printf("$PMTK220,1000*1f\r\n"); //1 Hz udpate
+
+ _UltimateGps.printf("$PMTK225,0*2bt\r\n"); //disable always locate (datasheet indicates that this negatively affects accuracy)
+ _UltimateGps.printf("$PMTK301,2*2et\r\n"); //set DGPS to use WAAS
+
+ //_UltimateGps.printf("$PMTK386,0.8*35\r\n"); //set Nav Speed threshold to 0.8 m/s
+ //_UltimateGps.printf("$PMTK386,0.2*3f\r\n"); //set Nav Speed threshold to 0.2 m/s
+ _UltimateGps.printf("$PMTK386,0*23\r\n"); //disable Nav Speed threshold
+
+ //_UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"); //GPRMC and GPGGA
+ //_UltimateGps.printf("$PMTK314,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"); //GPRMC and GPGSA
+ _UltimateGps.printf("$PMTK314,0,1,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n"); //GPRMC, GPGGA, and GPGSA
}
}
--- a/GPS.h Sun Apr 05 01:41:34 2015 +0000
+++ b/GPS.h Tue Apr 07 03:49:28 2015 +0000
@@ -34,8 +34,6 @@
public:
GPS(PinName tx, PinName rx);
- void Init();
- void Sleep(int sleep);
int parseData();
float time; // UTC time
int hours;
@@ -56,7 +54,21 @@
string fix;
string cardinal;
float kph;
-
+
+ //added by Ryan
+ int getGPRMC();
+ int getGPGSA();
+ int getGPGGA();
+ void Init();
+ void Sleep(int sleep);
+ void coldStart();
+ char mode; //manual or automatic
+ int status; //same as fixtype
+ float PDOP; //Position Dilution of Precision
+ float HDOP; //Horizontal Dilution of Precision
+ float VDOP; //Vertical Dilution of Precision
+ double degLat; //degrees latitude
+ double degLon; //degrees longitude
private:
float trunc ( float v);