What it is...
The "Christmas Lighting Control Unit" was developed for a simple purpose: switching all christmas lighting in the house on and off at the same appropriate time.
I used to have a total of eight timers throughout the house and the garden. The problem was, that although all the timers were syncronized at the beginning of the season, their quartz-clocks did not run at the exact same speed. The result: a difference of about one minute (fastest to slowest) after about four weeks.
This wouldn't be a problem if you had only one timer that switched a single light, but as the christmas lighting had to be plugged in in eight different power outlets, I wanted it to go on and off at exactly the same time.
The next problem with the timers was, that you could only program a static "on"-time - for example 16:30. But that fixed time did not match the changing dusk time at this time of year. So, at the end of november the time was just right while in mid december it was already almost dark when the lights went on.
But here's the solution: The ChriLCU!
We started by building a prototype...