Hi I'm making a programable led matrix and t a 6x6. I wAnt to drive each led by itself yet arduino only has 13 digital outputs. Anyone have any sollutions anything would help thanks!!
Multiplexing, charlieplexing, external drivers. Check the archives.
there's an 8 digit 7 segment driver( max7221 ) which might make this easier. One resistor is used to drive all the LEDs and the LedControl library handles accessing the device over an SPI interface. SPI needs only 3 Arduino pins.