🚀 go-pugleaf

In article <2082@puff.cs.wisc.edu> perry@garfield.CS.WISC.EDU (Russell Perry) writes:
>I've had this idea to take a LED clock and make it display something other than
>the time, but I don't know much about the things enough to rip it open and
>experiment.  Does anyone know how I could go in and change the display, most
>likely not even using the clock...

Definitely not even using the clock.  Modern digital clocks (you don't say
how old yours is, but only real antiques don't qualify) are very much
"single-point designs", with all the brains buried inside a single chip
which knows that it is a clock chip and nothing else.  What you'll be
doing, almost certainly, is saving the display and case and throwing the
electronics away.

You'll have to build your own display drivers from scratch.  If you know
how to drive LEDs, it's usually not hard -- LED displays are just a bunch
of LEDs with some pins in common.  A single-digit display (your clock
display might be made up of several of these) is 8-10 LEDs (depending
on what's done about colon and decimal point) with either all the cathodes
or all the anodes connected together to a single pin, and the other ends
brought out separately.  A one-piece multi-digit display may be like a
bunch of those, or may bus corresponding segments together so that to light
one segment of one digit you need to (e.g.) pull a segment line high and
a digit line low.

The hardest part will be that the display is probably a custom type that
you can't get a spec sheet for, so you'd need to experiment to figure out
the pinout.
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