Re: xAP and how to interface to a Pic Micro?

[patrick@xxxxxxxxxxxx]

--- In xap_automation@xxxxxxx, "Kevin Hawkins" <lists@u...>
wrote:
>    > -----Original Message-----
>    > From: Gary [mailto:questuk1@h...]
>    > Sent: 06 June 2004 14:28
>    > To: xap_automation@xxxxxxx
>    > Subject: [xap_automation] Re: xAP and how to interface to
>    > a Pic Micro?
>    >
>    > I will be writing the software using PICBASIC, i can do
>    > asm if needed?
>
> You might want to do this for speed or codesize but you could start
with
> PicBasic and see how you go - I would recommend as large a PIC as
possible
> to start with and then downsize when you get to optimisation and
know the
> likley codesize needed.

Gary, which picbasic are you using?

I have a PIC libary (in ASM) which parses and decodes xAP messages
(over a serial connection). Generating xAP messages is also trivial.
Calling this code from PIC basic should be straightforward - it would
great if you felt up to having a go at this and writing it up
afterwards.

>    >
>    > Can anyone tell me the timing of the transmitted data, is
>    > it anything like RS232 data?
>
> The data going out the serial port is standard RS232 asynchronous
data and
> so can be handled within PICBasic. xAP is just an 'on the wire'
software
> protocol it doesn't in any way define the physical layer so you can
choose
> your own serial data speed and format.

I have a simple xAP serial bridge, which takes xAP messages broadcast
over ethernet and relays them to a serial port and vice-versa.
In "real life" you would probably want to add some filtering
between
the ethernet network and the serial network for bandwidth reasons,
but at least you have a good starting point.

If you want either piece of code, drop me a line off list and we can
work something out.

Patrick