This tutorial shows how to interface eight LEDs to an Arduino using only two Arduino pins. This is made possible by using a PCF8574 I/O expander IC. A "Knight Rider" display is shown on the LEDs. Prerequisites Complete tutorial 4 – Arduino Knight Rider. Be able to use DIP IC packages, e.g. from tutorial 17. Components In addition to an Arduino Uno board, USB cable, wire links and a breadboard, you will need ...

In this tutorial, eight LEDs are interfaced to the Arduino Uno board. This is not complicated – it is just like interfacing a single LED to the Arduino as done in tutorial 3, but eight times over. A program is then loaded to the Arduino that will turn the eight LEDs into a "Knight rider" display. The following video shows what you will achieve: Prerequisites You will need to have completed tutorial 3 and it ...