A fairly easy way to do this is called multiplexing.  It is a method
where you can only turn on a few at a time, but because you turn them on
so many times per second, they look like they are on all the time.

Take all ten LEDs, and hook two cathodes to each of five pins (ie, LED 1
& 2 cathodes go to portB bit 0, LEDs 3 & 4 go to PORTB:1, etc) through a
resister.  (find out the LED current, and use a resister that gives it
that current at 5 volts)

Take the anode of one LED from each portb, so you should have 5 anodes.
Connect them all together.  Connect the other 5 LEDs the same way.  You
should now have 10 LEDs, with two LEDs sharing a port pin for five pins,
and two wires tied to the anodes of each set of 5 LEDs.

Use two transisters to hook the anodes to +5v, and have the transisters
controlled by two more port pins(say PORTB:5 & 6).  This leaves you with
one last pin, which won't be used for the LEDs.

Now, if you turn a transister on, then PORTB:0-4 controls one set of
LEDs.  If you turn the other transister on, then PORTB:0-4 controls the
other set of LEDs.

This ascii diagram needs to be viewed in a fixed spacing font, such as
courier new.  Windows users can pull it into NOTEPAD for this purpose.
_____
PIC  |      +---|<|--------+
    0|-/\/\-+---|<|----+   |
     |                 |   |
     |      +---|<|----)---+
    1|-/\/\-+---|<|----+   |
     |                 |   |
     |      +---|<|----)---+
    2|-/\/\-+---|<|----+   |
     |                 |   |
     |      +---|<|----)---+
    3|-/\/\-+---|<|----+   |
     |                 |   |
     |      +---|<|----)---+
    4|-/\/\-+---|<|----+   |
     |                 |   |
     |                 |   |
    5|-----------------+   | <-These last two pluses should
     |                     |   actually be transisters, the
     |                     |   PIC probably won't source as
    6|---------------------+ <-much current as 5 LEDs need.
_____|


-Adam


> Vernon Bradshaw wrote:
>
> Is there a way to illuminate more than 8 LED's using a single 8-bit
> port.  I am tryin to have a block of ten LED's increase or decrease by
> one when I press either an up or down button.
>
> Thanks,
>
> Vern Bradshaw
> WVBradshaw@worldnet.att.net
>