At 01:13 AM 9/15/2003 +1200, you wrote:
> > this problem.  If I am understanding correctly, you load the
> > chain of serial-in / parallel-out shift registers with one row
> > of LED data at a time, then light the LEDs by enabling the
> > row
>
>Yes, the array "scans" like lines on a TV screen. The row
>timing is based on a 200Hz timer IRQ => 200 / 7 refreshes
>per row per second, which is a little slower than I'd like but
>isn't very noticeable (and it is a work in progress - I think I'd
>revisit the thing armed with a grunty F452 or Scenix). One
>very bad consequence of too slow a refresh rate is that
>letters appear to slope as they move. It looks horrible

Hardware SPI can get the data out to the SRs pretty fast...

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

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