>> I've got a 5 x 5 LED matrix, which is driven by an 18F43K20 on
>> a one-LED-per-pin basis
>=20
> I assume the PIC is neither RAM, nor code, nor cycles limited in
> this application?  If so, optimize for maintainability

No restraint on anything, apart from it being battery-powered** so
I do need to keep an eye on consumption. It's possible that SLEEP
and WDT might be used instead of a timer IRQ. There will be time,
probably most, when there are no requests/LEDs to process, so
putting the PIC to sleep makes sense. INT0 IRQ is there for detecting
incoming requests. The 43K20 has s/w control of WDT for power-
down

The scheme you describe is much like the interrupt-driven HV PWM
project I have hosted at piclist, only with pots setting the values rather
than queue position number. It's certainly something I'd at least trial

** the customer has found a local supplier of a 3-pack NiMH, using
35AAAH sized cells, marked 345mAh. Also marked, unfortunately,
Made In China. They're perfect for fitting in the enclosure and I just
hope they're reasonable quality. The aim would be to charge them as
infrequently as possible, so some of his fancier ideas may have to be
shelved

Thanks

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