Lighting control system using Crozet microcontroller

["alan_singfield" <alan.singfield@xxxxxxxxxxxx>]

Hello group,

I've finally completed implementation of my lighting control system,=20
so I thought I'd tell you about it.

I wanted to have "lighting scenes" for my new kitchen, so I=20
investigated some of the commercially available options.

The system I came up with was based on the Croezet Millenium II=20
microcontroller. The version I bought has 12 low-voltage inputs and=20
8 mains relay outputs.

Four inputs are connected to clipsal push-switches, these select the=20
four lighting modes. Repeating the press on the push-switch cycles=20
through alternative "moods". A PIR sensor turns the lights out
when=20
there's nobody in the room.

As the outputs are relays, I initially thought I would not be able=20
to have dimming. However I had a brainwave and realised that I could=20
put a relay in parallel with a dimmer. When the relay is on, the=20
light will be full brightness, when it's off, current still flows=20
through the dimmer. This has turned out to be good enough for what I=20
need.

Programming the microcontroller turned out to be quite easy once I=20
got over the learning curve; you draw the circuit in an application=20
supplied with the system, run it in the simulator, then upload it=20
using a serial cable.

The controller cost =A3200 and the remaining parts less than
=A3100, so I think its worked out to be reasonably cost effective.
Has anyone else done anything similar (and dare I say it) for less=20
money?

Alan.