Issue 132 July 2001
Liquid Crystal Delight

Start • Working Glass Hero • Quarter Horse • Software To Boot • Widge Warrior • Highway Star • Beta Site • Take It Easy • Sources & PDF

Last summer I moved into a new house. It’s been quite an adventure, a combination of The Grapes of Wrath and “The Money Pit.” It’s great to own a brand-new house as opposed to a fixer-upper, but that doesn’t mean there won’t be issues, just different ones.
Case in point, as summer came to an end, I concluded that the builders had managed to connect a toilet to the hot water line. With a fall chill in the air, I found myself wondering if this was a new feature, kind of like heated seats in luxury cars.
As a former pool owner, I had seen the unfavorable effects of tepid water with all the hazards of a breeding ground for who knows what. So I presumed that after centuries of using a tried-and-true design, if connecting hot water was a great idea, it would’ve been done already. Well, a few more cold nights yielded complaints from the kids that the upstairs furnace wasn’t working.
Hauling out a ladder, I ventured up to my attic. There’s the furnace, but what’s this? It’s blinking at me. There was a lamp peeking out the side of the furnace repeating a two-digit, blink-pause-blink code of some kind.
Grabbing for the furnace manual (thoughtfully stuck in a rafter), I quickly found the translation: “Open the gas valve, you dummy!” After peering into the dark recess behind the unit and tugging aside some insulation, that’s just what I did.
Inevitably I would’ve checked the gas connection (i.e., whether or not it was plugged in), although I’ll bet your average furnace repair person has gone out on just such a call. Nevertheless, it was reassuring to have the furnace confirm the diagnosis, enough so that I felt confident reinstalling the attic access door as I climbed down.
A number of the furnace trouble codes deal with more significant problems and the manual offered some possible solutions to try (e.g., cycling power). Even more useful, some of the trouble codes are so explicit, they help you decide immediately if you’ll fix it yourself, call a repair service, or buy a new furnace before nightfall. I appreciated this relatively high-tech feature and suggest that the least you can do is consider designing in a single LED for even your most deeply embedded designs.
Moving up the pecking order of displays, you find the one- to many-digit vacuum fluorescent and LED displays. These can range from relatively cheap single-digit, seven-segment units to larger, fancier dot matrix displays. However, as you move up the size and features scale, the price and power consumption can quickly become problematic.

Photo 1—The Amulet Easy GUI Starter Kit ($399) includes everything you need to craft your own 1/4 VGA touchscreen display.

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