Homebrew PCBs

>>> Good thing you fixed the crystal.  That was required to make it work
>>> and too simple of a mistake.

no crystal is a 3 pin ceramic, the 3rd pin was missing. the caps are 
inside.

>>> A question is why the diode on MCLR ?

in circuit programming, was connected wrong, now fixed.
and header for programming added.

>>> Another question is why all the shift registers to only light a few
>>> LED's ?  And why the transistor on the LED's ?  The shift register
>>> can handle 20mA in a drain mode, and each LED can be run at 10mA so
>>> there are lots of unneeded parts.  OR... more likely many more parts
>>> that are not shown.

uses pretty heavy leds with up to 30mA each (res. changed).
Not sure about the shift reg., one could code them into the pic i guess.
maybe it makes code simple. they cost nearly nothing so why not.


> It looks like it can have three different outputs going at the same
> time, each with two led's. The schematic shows PNP transistors for the
> led driver, I think they should be NPN, though.
me too, changed that already.
PNP would work, though better on the high side.


> The shift registers are all clocked by the same 555 timer (40KHz ?)
> maybe so the on/off times are consistent.

Not sure about how it is intended to work. Karega is sure it must be done 
this
way, i asked.

ST