Hand tools and fabrication machines
The aim of Charlieplexing was to use a selected number of pins and connect maximum number of LED’s, so that each LED will light up individually.
The formula for Charlieplexing is:
Where n is the number of pins used.
A lookup table was drawn out to identify the pin pattern to light up each LED individually.
PDDR: Port Data Driven Register.
PDOR: Port Data Output Register.
A: Pin A1
B: Pin A12
C: Pin A2
The Schematic Diagram for the Chalieplexing: