You're forgetting the duty cycle effect.
With a frequency generator, your one column is getting 50% activation.
With the PIC scanning all columns, you're getting 1/128th duty cycle (0.8%).
You need to drive the LED's MUCH harder for the duty cycle you have.
And it's a good idea to use a retriggerable monostable driving a fast
switch in the power side of the LEDs. That way if your software hangs,
you don't smoke/fry/toast/burn/zap the LEDs. Set the mono to about 3x the
duty cycle to allow for some margin, and retrigger it with every write
to a new column.

Kurnia Brahmana wrote:
>
> [PIC]:
> Thank you for suggestions those come from
> Aaron Lahman, Spehro Pefhany, Jinx, and Dale Botkin.
>
> I have it tried with a transistor as a driver for every column, when tested
> every columns sink about 40 mA
> to the GND. BUT whenever connected to the PIC16F84
> every columns sinks only 3 mA. I wonder if the scanning
> frequency coused the brightness down. However, when the led connected to
> frequency generator with 128x50 Hz
> the light strill bright, mean while the scanning frequency have adjusted to
> 128x50 Hz.
>
> Again, thank you  in advance.
> I'm waiting for any suggestion.
> mikronik@mdn.prima.net
> Kurnia Brahmana
>
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