Jinx wrote:
>
> IMHO 3V is just too low for that circuit. If the high- and low-side
> drivers each drop a volt (the 2003 at least has Darlington outputs),
> after the current-limiting resistor that leaves crumbs for the LEDs.
> And the LEDs are an important part of this project

Something I'm not clear on, though, is why high-side drivers are needed at
all.
Only one column is "on" at any one time, right?  They're being multiplexed?
So each PIC output pin on the "high side" is only driving a single LED at
any one time, right?

It's obvious why each column needs a high-current sink, but there's
something I'm missing here...


David Meiklejohn
www.gooligum.com.au


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