For those who are curious about the furnace controller, here's the stats for the last 48 hours:
http://www.delorie.com/house/furnace/20060116.png Yes, the temp dropped 50 degrees in 12 hours. The gap was a 2 hour regional power failure. I continue to tweak the control software as needed; recently adding "run fan occasionally" and "manage humidity better" features. Noise and glitches continue to plague me occasionally, but then again, the board is mounted next to an electrostatic filter. The system has cost me about $500 so far, but it's given me enough information to realize that (1) the AC needs to be serviced in the spring, and (2) running the woodstove saves me 50% of my fuel oil :-) Yup, it's paid for itself and it's next upgrade already! The plan is, once I catch up on other projects and have some time, to redesign the controller board with a CPU on it so that I can get rid of the separate PC. I'd like to have the ethernet cable go right to the furnace. So far, the design is to have an R8C/Tiny CPU for each zone, and something running linux (xscale/dram/CF perhaps, like a gumstix) to coordinate everything. All on a 3.5 x 5 board. So now you know why I'm still interested in gEDA/PCB :-) FYI I've been building a spreadsheet of current prototype PCB fab houses, there are a number of inexpensive options these days, at least, if you don't mind dealing with foreign businesses (and if you can figure out their pricing structure from their web page). For example, Sierra Proto Express offers: 4 layer 6/6 w/ mask and silk, up to 60 sq in, $51/ea for qty 3+.
