you wrote:

> At 16.57 1995-11-05 +0000, Walter Andersson wrote:
>
> >I've put together a simple circuit board for use in prototyping PIC
> >projects.  The board is constructed using wire wrapping techniques.
> >I've hooked the proto board up to a simple breadboard circuit
> >consisting of LEDs and resitors connected to each of the ports on
> >port A & B.
>
> I hope you don't overload your PIC with all these LED:s. Normally each
> LED should get 10-20mA and 10 of them should have up to 200mA, way too
> much for our little friend. For the PIC16C5X series the absolute maximum
> rating is 150mA out of the VSS pin and max 50mA in to VDD pin. Max output
> sunk by a single I/O port is 50mA and max output current sourced by a
> single I/O port is 40mA. Each port pin can take 20mA alone (sourced) and
> 25mA (sunk). Well, maybe it works anyway but it wont hurt to be on the
> legal side ... :)

I have some LEDs connected to a PC16C84. They are 4x7segment displays
for a game for my daughter. I have connected the LEDs directory as
a 4x8 matrix, and I multiplex 1/8. I reasoned that this was not going to
get things to hot (i.e. max 4 LEDs at any one time). Also, over driving the
LEDs a bit seems to make up for the low mux rate.

Seems to work fine.

With 13 IO lines I have 4 x 7 seg digits (plus decimal point) and 6 buttons
and a buzzer (piezo). I did have to put diodes in with the buttons !

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