LED Matrix display

[HenrikOlsson]

Hi Art,

TRIS 0 for the pin, and value 0.
Does that not mean it won't source or sink current?

No not really, with TRIS=0 and Port=0 it WILL sink current..... In relation to the schematic in your second post:
If you set TRIS=0 then pin is an output. If you then set the pin low it will sink current so (only) the upper LED will turn on, if you set the pin high it will source current so (only) the lower LED will turn on - so far so good. But if you set TRIS=1 the pin is made an input and will not source or sink any current but since the LEDs are connected in series across the supply they will both turn ON - not off.

If Charlieplexing isn't what you meant I must confess I don't quite follow.... I'll re-read your initial post a couple of more times to see if I can figure it out.

/Henrik.

EDIT: OK, you squeezed in a post while I was typing. The two LED "matrix" you show in your latest basically IS how Charlieplexing works.