Some RTC chips have built in alarms, but there is no particular chip
that does exactly what you need.

You could use an RTC and a PIC, and have a list of times that the PIC
needs to do something.  Every time the alarm goes off, the PIC
performs the action, then looks at the list of alarms and sets up the
next alarm in the RTC, then sleeps until the alarm goes off.

You could also do it all inside the PIC, having it run off a 32kHz
crystal.  Use the EEPROM or FLASH to hold the event times.

-Adam

On 9/28/06, Luke Sheridan <piclist@bearwoodproducts.com> wrote:
> Hello,
>
> I would like to design a circuit that activates at a certain time of
> day, on certain days of the week, to control architectural lighting.
> Similar to a home-automation system. It seems like this would be a
> fairly common desire, is there a chip that does this or some example
> code out there? I tried to search for it but came up empty handed.
> This will be interfacing a PIC that is going to be sending out midi
> and spi control signals, that pic is already pretty much loaded so
> I'll be using another one dedicated for the time keeping operation,
> I'd like computer control to be able to update events.
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