Thanks for the comments guys, I'll keep in touch as the project starts to roll, tempted by Dwayne 4
on 8 pins :-)

Hi again Roman, hope u r well; it's external, 'user' won't expect anything, although part 2 could be
the internals.

I ddi consider breaking it up[ over several pics, but decided I'd ask the expert folks on the
PIclist first! I now plan to prototype it on 877, and take it from there. I'll develop code step by
step, see how it fares

Stuart
----- Original Message -----
From: "Roman Black" <fastvid@EZY.NET.AU>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: 04 January 2003 16:31
Subject: Re: [PIC] Multi-zone external light controller with softstart


> Stuart Meier wrote:
> >
> > I have just re-joined the list as I have a project to build a 9 zone external light controller
(UK,
> > "230"v), driven from PIRs, push buttons at each exit door etc.
> >
> > Planning to use a 16F877 running at 20mhz, zero-crossing detection, phase angle firing
>
>
> Hi Stuart, design it from the back first. The user is
> going to allow a decent delay after walking into the
> room before expecting the light to come on. The triacs
> etc need zero cross triggering.
>
> Why not design an int (or poll) at 100Hz, in sync with
> your mains, and do all your processing and triac
> firing there.
>
> No user is going to be unhappy with 1/100th second
> delay and it makes your software job much easier. :o)
>
> For triac phase ramping etc you can just add a delay
> after your main code event every 100Hz.
> -Roman
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.
>

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