RE: Progress on the xAP to C-Bus gateway

[Kevin Hawkins]

Now tried a small PIC based implementation with a tcp/ip stack and it’s
not going to fly I don’t think – at least not without a lot of really tight
coding and moving to big PIC chips – not impossible by any means but I feel
it’s going to constrain the features substantially. Getting a web server
(requires tcp on top of udp) & is really going to push it. I still
have to
look at using one of the Ethernet assistant devices connected to a PIC as a
solution but none of them has arrived yet.
Have also received and been playing with the Rabbit development kit and
it’s great – although I don’t know C so I have a lot of late night reading
to do, and probably will be expanding my 4 letter word usage. However the
supplied tcp/ip libraries seem good, and are license free. After my 'hello
world' xAP messages I now have a little xAP clock application running on
the
device (send only). It checks the time with one of the online internet
synchronised time servers every hour and just throws out a xAP message with
the exact time every 10 seconds. So I am enthused that what I had worried
about with the whole Ethernet interface is now very do-able. This is really
much the same hardware model as Patricks Rocket xAP serial board. Strangely
satisfying when such a small device just sits there silently sending xAP
packets and blinking it's led's - (sad git - makes a note must get out
more). There are obviously a large number of spare I/O lines on the Rabbit
board that could allow for digital i/o (relays) or even momentary switches
to be integrated into your C-Bus world. It may be possible to link Ian's
xAP I/O board (and relay board) to C-Bus transparently this way too.
There is a cost implication in that I am moving from a £10 PIC part
to a £50 Rabbit core part - plus the pcb and associated components so we
would be up at least another £40 on the PIC based solution - however as
many
people have commented having invested in C-Bus they obviously don't want a
half baked ,price constrained piece of kit so I'm happier here.
Will keep you updated - if anyone is prepared to act as an 'ask me a
silly C question' advisor let me know - I've had a few already, none
pending
though.

Kevin