Changing GPS co-ordinates into Degrees-Minutes-Seconds

[ScaleRobotics]

Well, then...........

There are a couple different ways to do it. I'm going to show you the Serin2 example, because that is the gps example that MeLabs gives.
Another good way to do it is to read the entire NMEA sentence into an array like this, then worry about parsing it later:

HSerin 200, Main, [WAIT("$GPRM"), STR gpsdata\MAXDATA\13]

but we will stick with serin2 for now.

Here is MeLabs gps example for reading speed.
http://melabs.com/resources/samples/...d/read_gps.bas

You would have to adjust to get degrees minutes and then do a conversion for seconds
For instance, their ...

SerIn2 GPSin,baudGPS,Timeout,Nogps,[wait("$GPRMC"),skip 34,DEC1 tens,DEC1 digits,skip 1,DEC1 tenth]

means wait till it sees $GPRMC that begins the NMEA sentence, skip 34 characters to the speed tens digit, put it in variable "tens", then read next speed digit and put in variable called "digits", then skip the "." and read the last decimal into a variable called "tenth".

You would have to adjust the skips to match the digits you want to get.

$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A

Where:
     RMC          Recommended Minimum sentence C
     123519       Fix taken at 12:35:19 UTC
     A            Status A=active or V=Void.
     4807.038,N   Latitude 48 deg 07.038' N
     01131.000,E  Longitude 11 deg 31.000' E
     022.4        Speed over the ground in knots
     084.4        Track angle in degrees True
     230394       Date - 23rd of March 1994
     003.1,W      Magnetic Variation
     *6A          The checksum data, always begins with *

If your NMEA sentence was similar to above (some add more resolution and are of slightly different format), then you could use:

SerIn2 GPSin,baudGPS,Timeout,Nogps,[wait("$GPRMC"),skip 11,DEC2 lat_deg,DEC2 lat_min,skip 1,DEC3 lat_min_dec ... then same for longitude]

Now, you need to convert decimal minutes to seconds .... am I right this time? Because the GPS will output in decimal minutes, not seconds.

So, to convert decimal minutes into seconds:
lat_seconds = lat_min_dec * 6
so, using the NMEA sample above: 038 * 6 = 228

When you print this out to your computer, you print a "." in between the twos
and get 2.28 seconds. This part just prints the seconds out through the serial port.
The dig specifies which digit you want to print of the variable called seconds. Rightmost digit is 0

DEBUG DEC lat_seconds dig 2,".",DEC lat_seconds dig 1, DEC lat_seconds dig 0,13,10