He sylvain,

the easiest is to add all the bytes that you are sending to a temp byte.
Don't care about the overflow of this byte since it is not needed.

When you have send all the byte in small packets like an s-record does,
you get a byte value. The checksum is then the value that is needed to
get the temp byte to zero. so if the temp byte holds 50, the checksum is
50, making 100, don't care about the overflow so the checksum tempo byte
is zero. This checksum you send as last.

If this checksum of a byte is not enough you can change it into an int
or something

Hope this helps,

Regards Richard Meester
Software engineer.

Sylvain Bilanger wrote:
>
> Hi everybody,
> Can anyone give me a good example or just a good site where i can
> understand the how to of checksum's?? I'm doing serial comm and i need
> some kind checksum's to make sure everything works fine.
>
> Thanks all for the help!
> Sylvain.
>
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