[rjcauc81hi]

I am creating my own own custom NMEA string (to maximize bandwith required) but I need an example on how to create the checksum value.

An example in Java would be GREAT! For the benefit of others, you may be an expert with C and would like to offer an example as well.

[jack44]

Check http://www.gpsinformation.org/dale/nmea.htm page for any information about NMEA strings.
The checksum field consists of a '*' and two hex digits representing an 8 bit exclusive OR of all characters between, but not including, the '$' and '*', so it's not a sophisticated checksum.

[rjcauc81hi]

Jack

Bless you fulla. I can see what the checksum is. To be honest I do not know explicitly what it is used for nor how to create it. I merely wish to follow protocol if I am going to define my own sentences. Not that I really need to, to be fair...

[peter_k_john]

Originally Posted by rjcauc81hi

Jack

Bless you fulla. I can see what the checksum is. To be honest I do not know explicitly what it is used for nor how to create it. I merely wish to follow protocol if I am going to define my own sentences. Not that I really need to, to be fair...

Hi,

See this link it containes some information about checksum of NMEA.

http://www.codepedia.com/1/Calculati...NMEA+Checksums

And you can also get lots of other results by just googling with key words "Ckecksum NMEA"

Regards,
Peter