GPSSerial library

[schimanski]

Hello agraham!

One example for the same position:

With GPS as GPSDriver-Object:

GPS.Latitude=51.029435
GPS.Longitude=5.99185

With GPS as GPSSerial-Object:

GPS.Latitude=510.173,850
GPS.Longitude=55.951,450

[agraham]

It looks like your readings are a factor of 10 out but I don't see that problem here. I am sure another user would have meantioned this if it were a general problem. Are you using two different GPS receivers for the GPSDriver and GPSSerial apps?

I have a test program that I wrote for GPSDriver and then, like you, transferred to GPSSerial. I've just run the two side by side.

My HTC Diamond with internal GPS receiver using GPSDriver and my Axim X30 with an external Bluetooth Fuzion GPS receiver running GPSSerial both give almost the same latitude and longitude readings.

The latitude and longitude are taken from the $GPRMC sentence. If you can look at the contents of that sentence that might give a clue as to what is happening.

[agraham]

Originally Posted by schimanski

With GPS as GPSSerial-Object:

GPS.Latitude=510.173,850
GPS.Longitude=55.951,450

Should those commas be there? Is this a culture thing? Are those erroneous readings actually 510173.85 and 55951.45?

[schimanski]

Should those commas be there? Is this a culture thing? Are those
erroneous readings actually 510173.85 and 55951.45?

I have checked it and the commas are there.

You are right, that I use two different GPS receivers. For the GPSSerial I use a DiMP3 bluetooth receiver (SirfIII) and my device has an internal SirfIII.

I have read the NMEA-sentences with your testapplication GPSSerial on the device and the desktop:

Both RMC-Sentences are the same:
GPSSerial: Latitude=5101.7372, Longitude=00559.5017
GPSDriver: Latitude=5101.7505, Longitude=00559.5182
(with the typical receiver difference)


But I have noticed, that GPSSerial shows on the device and the desktop this format:

GPS.Latitude=510.173,850
GPS.Longitude=55.951,450

But I need the following, because it is the format of the GPSDriver-Lib (displayed with the GPSDriver-testapplication):

GPS.Latitude=51.029435
GPS.Longitude=5.99185

What can I do without modifying the code for desktop and device?

[agraham]

Originally Posted by schimanski

What can I do without modifying the code for desktop and device?

Wait for me to post tomorrow a slightly modified GPSSerial that can cope with OS culture settings where the decimal separator is a comma. It is an oversight on my part (I think). I assume that your culture settings on your device and desktop are German and this is causing the decimal point to be ignored when converting the NMEA data as it is being interpreted as a group separator and not a decimal point - hence the value comes out about 10000 times too large. I need to override your culture settings.

I haven't had to deal with culture dependent formatting before. Can you tell me when you use Basic4ppc and enter decimal data do you have to use the decimal point and not a comma for decimal data? Also what happens with the following three lines of code

test1 = 10
test2 = test1 + 1234.567 ' UK and US number format
test3 = test1 + 1234,567 ' European number format ' does this error?
msgbox(test2 & crlf & test3)

GPS.Latitude=510.173,850

Do you know how that number is being formatted for output. Are you using Format()? I am puzzled why it comes out in European format as I thought that Basic4ppc enforced the use of US standard numeric formatting.

[agraham]

Version 1.2 now posted has a small modification to hopefully cope with computers whose culture settings use comma rather than full-stop as a decimal point separator.

Also added to the GPSSerial object are four new properties that return the last copy of each NMEA sentence that was parsed to provide the GPS data. These sentences are complete with checksum. It is probably easier to use these properties than parse the sentences out of the stream of data returned by the NMEAReadXXX methods.

[schimanski]

Hello agraham, thanks for your fast help.

test1 = 10
test2 = test1 + 1234.567 ' UK and US number format
test3 = test1 + 1234,567 ' European number format ' does this error?
msgbox(test2 & crlf & test3)

The result is test2=1244.567, for test3, I get a syntax error.

I have test also the new GPSSerial.Lib. Now I get:

GPS.Latitude=51,029435
GPS.Longitude=5,99185

The calculate of the distance etc. are wrong. I think that it is the comma. Instead of the comma there must be a point....

[agraham]

Originally Posted by schimanski

I think that it is the comma. Instead of the comma there must be a point....

Sorry, I overlooked a line of code that I should have fixed as well. I now realise where the formatting comes from that puzzled me earlier. I'll fix it tomorrow. It's a bit tricky to fix this stuff that doesn't occur on your own computer

[agraham]

Version 1.3 now posted is hopefully now immune to OS culture setting problems.

[schimanski]

Yes, agraham! I have tested the new lib in my application and it runs perfect!

much thanks...