On Thu, 6 May 1999 08:58:50 +0100 Brian Jones <bejones@HURSLEY.IBM.COM>
writes:
>Not my idea I'm afraid but also check out the June 99 (yes - it
>came out last week!) edition of the UK magazine Everyday
>Practical Electronics.
>
>It has a PIC based sundial. When the shadow drops over one of the
>hour markers the hours pip and the tune 'You are My Sunshine'
>plays. Looks like a few other fun features also. Probably not up on
>their website yet but their normal practice is to make the source
>code available for FTP.
>
>Brian
>Brian E Jones
>Centre for Java Technology
>IBM HURSLEY
>


        Neat project!  Especially the "You are my sunshine" part, which
is a favorite with my wife.  Anyway, I can see how this project could be
struck by creeping featurism...  It could be a sundial with a digital
display where there's a "noon detector" that sets a calibration factor
for the processor clock so it can correctly time the rest of the day and
night.  Although a bit more difficult, it appears there could also be a
shadow length detector which could be used to determine the date and
latitude (given enough time for the shadow to reach its maximum length).
        Some interesting stuff on clocks and the measurement of time is
in the book "The Discoverers."  As I recall, the original mechanical
clocks had 12 hours from sunrise to sunset, but they had to keep being
adjusted since the amount of "time" between sunrise and sunset varied.
They came up with elaborate mechanical methods to automatically adjust
the clock before finally coming up with the idea of letting there be time
after sunset and allowing the sunrise and sunset times to vary.


Harold




Harold Hallikainen
harold@hallikainen.com
Hallikainen & Friends, Inc.
See the FCC Rules at http://hallikainen.com/FccRules and comments filed
in LPFM proceeding at http://hallikainen.com/lpfm

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