Pedro Barrios wrote:

> I'm trying to find a way of displaying a message in a 5x7 LED
> array.

  The "Times Square" display thread re-surfaces!

> I was thinking about having a message array 32 bits long by
> 5 bit wide containing the information I want to display.

  Which way up is the display?  Usually the 7 vertical and the 5
horizontal.  As such, you have described a vertical message stripe.
Surely not?  Or are you going to use it on its side, only five bits
high?

> I would then take each one of the 32 bit words and rotate sequentially
> bit by bit and display the 7 most significant bits after each
> rotation. I would do this for each of the 5 rows of the LED display.

  A way of driving a *single* 5 by 7 display, is to use an 8-bit shift
register (e.g. 74HC164) into which a column of 7 bits is loaded, the
column multiplexer is disabled, the latch in the SR is updated and the
new appropriate column enabled by multiplexer.  If you're really
cunning, do the column multiplexing with an HC4022 octal counter/decoder
whose clock is the latch enable and reset is the eighth bit of the shift
register.  Result: 3-bit interface to the PIC (data, shift clock,
latch).

  Code to do this and read character tables?  Well, best describe
exactly how you wish to view or scroll and what characters, first?

  Cheers,
        Paul B.