> 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?

Yes, I have.  But before we get too far, is this a commercial project (in
other words a real budget) or a one-off hobby project?  (Sorry, but I've
gotten caught on this before, especially on this PIC list.  After spending
time with several emails back and forth sending descriptions, specs, and the
like, I finally discover that the other person is expecting code for free
and never had an intention to pay for anything).

Not quite a year ago we created a custom system for sequencing power to a
piece of industrial equipment that has lots of individual DC supplies and
other things that need to be separately switched.  We deliberately kept it
general so that it would be applicable in a variety of applications.  It has
switched AC outputs, digital outputs, digital inputs, and configurable
analog window detection inputs for sensing of DC power supply outputs.  It
can be controlled from a host via a serial line, but the sequence of
operations can also be programmed into the unit and saved in EEPROM.  The
unit also reports current status, operations, and failures back to the host.

Let me know if you want more detail.


*****************************************************************
Olin Lathrop, embedded systems consultant in Devens Massachusetts
(978) 772-3129, olin@cognivis.com, http://www.cognivis.com

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