That is byte stuffing and is part of the serial protocol stack (HDLC?  if
memory serves
me right).

What I don't understand is why you even saw them.  Are you looking at the
raw stream?
I would have thought they would have been transparent to you because you'd
be
looking at the ends of the communication above the serial stack.

eric


On Mon, Jul 28, 2008 at 7:02 AM, Anton <[EMAIL PROTECTED]> wrote:

> The timer is all right.
>
> I realized what was the problem.
>
> Serial port communication played a trick on me. The program which I used
> to read the port gave out data bytes 0x7E and 0x7D as 0x7D 0x5E and 0x7D
> 0x5D. This is because byte 0x7E is reserved as a frame delimiter, and
> 0x7D is reserved as an escape byte, so if such bytes are in the data
> payload they are changed to the pair of 0x7D and (the reserved byte) XOR
> 0x20.
>
> Anton.
>
>
>
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>



-- 
Eric B. Decker
Senior (over 50 :-) Researcher
Autonomous Systems Lab
Jack Baskin School of Engineering
UCSC
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help

Reply via email to