 Charlieplexing was proposed in early 1995 by Charlie Allen at Maxim Integrated following public disclosure to the PICLIST by Graham Daniel (at that time g.daniel.invent.design) of his design using PIC chips to drive rows and columns of bidirectional LEDs.After some discussion on the PICLIST the idea was accepted by the PICLIST community and later was included in a Microchip tricks booklet, but with no attribution.Graham at the time created simple circuits with PIC 12C508 chips driving 12 LEDs off 5 pins with a mini command set to set various lighting displays in motion.