The November 27, 2008 issue of EDN (page 59) or located here describes the latest of the "plexing" approaches to driving multiple LEDs with few uC ports.
Chipiplexing (derived from the author's nickname) has some advantages over Charlieplexing, including driving N-1 LEDs simultaneously, using only N additional NPN/PNP (very cheap) transistors.
Richard
Chipiplexing (derived from the author's nickname) has some advantages over Charlieplexing, including driving N-1 LEDs simultaneously, using only N additional NPN/PNP (very cheap) transistors.
Richard