programmed to switch sprinklers on
up to eight times a day, on the days
of choice. Just what we needed!
The plan was to use a PIC and
custom electronics that would be
programmed to accept input from
the timer, and produce appropriate
drive for the clapper relays.
The features we required were:
1) Westminster chime to play
four times each weekday,
only at the desired times.
2) Manual use as an option.
3) An urgent calling bell played
prior to the start of a
4) A joyous peal that could be
rung on occasions such as
5) A solemn toll that would be
appropriate for funerals or
times of mourning.
Final front panel of the new controller.
The complete system schematic. Timer input is from the sprinkler controller. The PIC is mounted on the board behind the
panel, and other parts of the circuitry are on the original PCB.
August 2012 43