We’ve been putting LED “candles” in the windows the last several years. Having tried a couple different commercially-available varieties and having been uniformly disappointed, I thought that I might as well make my own.
I can’t quite get over that it seems like terrible technological overkill, using an ATmega328P and a DS1307 RTC just as a lamp timer. But I guess that’s one of the great things about this stuff, even under-utilized, it can be quite economical. The electronics for these worked out to around $15 per copy. Add a couple bucks for wood and CPVC pipe, and they’re still quite competitive with examples at the local big-box stores or on the web. And they work exactly the way I want!
I’d previously made some RTC breakout boards, so I just plug them into the main board, so that I can re-purpose them off-season if desired. Although it would have been fun to try to develop a candle-flicker algorithm with PWM or whatever, I got lazy and just got the LEDs with the built-in flicker chip from Evil Mad Science.
So quick-and-dirty, but it was also a fun little project, and it does something that I want. They look quite convincing from the road! More pictures here.