How to drive a lot of LEDs from a few microcontroller pins.

Step 4 Smaller and more versatile...

Since most of the board is taken up by the LED array, we can make room
for either a Attiny chip OR a microchip PIC12F chip. Shrink the LEDs down
to 3mm and go to a double sided board, and we get something about 27x44mm

Alas, this board hasn't been tested yet...