On 3/18/06, Crist=F3v=E3o Dalla Costa <cdallacosta@gmail.com> wrote:
> I think that a better way to achieve what you want would be to have a sin=
gle
> resistor in series with the common of all leds

Not a resistor but a controlled voltage device.
If you'll use a resistor, you'll have different brightness for
different displayed simbols.

 I'm doing this all the time I'm using 7 seg displays. The simples way
is to use a controlled zenner in series with the common electrode of
display.
The voltage across the zenner is compensated the FET "saturation" of
the output driver stage.
So you need a binary controlled resistor for a 2^n levels of brightness.

Vasile

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