On Tue, 17 Oct 2000, Carl Ranson wrote:

> Hi all,
>
> I've thought of what I think would be a good project for a pic. I would like
> to have a 8 channel relay board that is controlled through a standard serial
> interface.
>
> ie. PC->Serial->Pic->8*Relay
>
> It would also be nice to have the Pic able to report the status of each
> relay back to the host.
>
> Has anyone done a circuit like this already?

I worked up the hardware design a few months ago for one for a friend.
He's got a Linux machine (modified I-Opener) in his car and wanted it to
be able to control doors, windows, etc.  I did write some code for it, but
it was for the BS2, so I'd want to rewrite it in C instead.  The hardware
is, of course, dead simple...  all you're doing is turning on relays.  The
details depend on how much current/voltage you plan to switch, which
determines (to some degree) how big the relays are, which determines
(again, to some degree) what the drive requirements are.

Dale
---
The most exciting phrase to hear in science, the one that heralds new
discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
                -- Isaac Asimov

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