PIC16F84A Matrix LED Display

[Demon]

I don't understand why column 15 is wired differently than the others.

Robert

[mark_s]

I think this is how it should be wired. The original had all the pic outputs shorted?

[AvionicsMaster1]

I think you're correct in wiring the rows to a port pin on the pic.

After looking at the datasheet I see the 16F84 can sink/source 25mA per pin. Now I see why you'd want to use that chip. How would you do it with a 16F877A where the pins are not as robust? That was the chip I was planning on using is the reason I'm asking.

[Demon]

I think you're correct in wiring the rows to a port pin on the pic.

After looking at the datasheet I see the 16F84 can sink/source 25mA per pin. Now I see why you'd want to use that chip. How would you do it with a 16F877A where the pins are not as robust? That was the chip I was planning on using is the reason I'm asking.

I'd sink via transistors; cheap and simple.

Robert

[dineshwick]

@mark_s : Yes you are correct, There was a mistake in the Schematic, I fixed it. Thank you very much, Please see the corrected one.
http://www.manelsoft.com/projects/pi...d_display.aspx