Wagner,

In my original question, I referred to using the LED modules with cascaded
595s, but that was just an example.  I ask the question .. well .. because
I didn't know the answer <g>.  I have read every response and was actually
able to follow some of them :).  I have often seen references to FPGAs and
PGAs and wondered about their use.  How are these devices used ? Do you use
some type of programmer to program them to perform a specific function ?

Eric

-----Original Message-----
From:   Wagner Lipnharski [SMTP:wagnerl@EARTHLINK.NET]
Sent:   Tuesday, February 23, 1999 11:37 AM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: How to display 0 - 100% on an LED bar

Eric Oliver wrote:

> Whack !! Ouch !! Gotta stop whacking my forehead like that. Ok, that's
> easy. So if my load measurement is say 45000 then I need the first (
> 65535/30 = ~2184, 45000/2184 = ~21 ) 21 LEDS lit. Shift out 9 zeros then
21
> ones. I guess I was making a mountain out of a mole hill !!

Oh well, that's an easy solution, but shift out to where?

Unless the LED modules have a shift register that accept serial
(data/clock)
and with a "borrow" output allowing to cascade several modules.

You can also use a fpga logically programmed to convert 8 bits (the high
order counter byte) into a 5x6 matrix... or 3x10... or something else, and
never needing to use a microcontroller, oscillator, nothing else.

Wagner