Hi Jinx Soft stop would just be for elegance, fades away not dump you in the dark if you are out of range of PIRs :-) zc, opto isolated, don't like 240v potential down low voltage wiring :-( Not decided on the PBs yet, but they will be chosen for appearance not electrical performance, so some signal clean up may be a good idea. TX Stuart ----- Original Message ----- From: "Jinx" To: Sent: 04 January 2003 10:52 Subject: Re: [PIC] Multi-zone external light controller with softstart > > (and 'soft stop'?) > > Wouldn't worry about that > > > I intend to use an ISR to generate a tick perhaps every 250 usecs > > 250us @ 20MHz is over 600 instruction cycles. Plenty, I'd have > thought, with 25,000 (10ms) IC between zero-crossing points > > I recall a suggestion that slices of 100us works well but 250us > would be OK for just ramp-up from off to on. Even after 9 updates > there's still 8ms until the next z-c > > How are you doing the z-c detection btw ? > > > b) debounce PBs by reference to ticks > > You could add an RC to lessen/eliminate switch noise and use a > shorter switch debounce routine. Choosing a classy pushbutton > pays off too > > It doesn't sound like the PIC would have too much trouble supervising > a circuit like that. Some paperwork and a flow diagram for the code > beforehand wouldn't be a bad idea, to get all the timing nicely dove- > tailed > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.