Quote Originally Posted by scalerobotics View Post
The checksum is used to ensure the device reading the gps doesn't receive faulty input. If it is important for your application, the Pic chip can be made to perform a checksum on the sentence, and compare it to the one the gps calculated. If it differs, the data read from the gps is corrupt, and must be read again.
Thanks a lot. I think I need to sit down with the manual for sometime to learn about different conversions and decimal substitutes. Seems little complicated for now.

But I still wanted to ask you that how do I checksum the data in PIC? I mean my PIC gets everything in a string which is comming from the GPS in the first place. Why it is a number, what does this number do?

Can you please put up the code you have done as it will be far far easier to understand somthing working than perform a reverse engineering technique on it. From a beginners point of view what you explained above about checksum has gone past way above my head.

Thanks