picdimmer

[Grand Poobah]

Renard is a mini-project involving a PIC-based Computer-Controlled Light Dimmer, mostly for controlling incandescent display lights (such as Christmas displays). This light dimmer is a low cost, low chip-count solution using a commonly available PIC microcontroller to control (on, off, and dimming) up to eight lamps (or light strings) per controller.

The basic idea is that someone can use the serial port on a PC to control and animate a light display, often synchronized to music. For example, a light display using exterior Christmas lights could show Santa and a sleigh with reindeer moving across a lawn or the face of a house in time to 'Rudolph, the Red-Nosed Reindeer' or some other relevant Christmas song. There are many other possible uses as well, including other holiday or more permanent displays.

This project involves only one piece of the puzzle - the low-power control electronics that accept commands from a PC and provides on/off/dimming signals. It is a DIY (Do-It-Yourself) solution, since there are not currently any kits or finished products available. More information about this sort of process can be found on the web, including the http://computerchristmas.com site. The basic PIC controller can control eight lamps, but multiple PICs can be daisy chained together to control up to 128 or more lamps through a single serial port on a PC.

Some other parts that are needed can also be found of the web, including PC software for choreographing and running the show (http://www.vixenlights.com, and solid-state relays (SSRs) (http://computerchristmas.com) for supplying power to the lights.

Since this is a DIY design, the user can select various communications methods to suit the interface and distance requirements, including RS-232, RS-485 and current loop.

There are often related discussions going on at computerchristmas.com and at the vixen software support forum.