Over at tronixstuff John has written another tutorial showing how to interface an Arduino with various parts and in this example the reader can learn how to use the 74HC4067 IC. Although not the newest of parts, it's a simple way of selecting current flow between a 1-16 divider - and can be used to expand individual digital outputs or add more low-resolution analog inputs to the board. Here's a quick example of the outputs at work:
As an interesting aside the tutorial uses Arduino port manipulation as an efficient and fast way of controlling Arduino digital output pins, which is much simpler than multiple digitalWrite() functions in a loop. With the supplied example sketches and explanation you'll be up and running with the 74HC4067 in no time. To learn more, visit the tutorial page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
When adding external circuitry such as the soft switch described above to your project, and need to make it more permanent than using a solderless breadboard - consider our range of ProtoShields. From the tiny LeoStick to the Mega range, we offer a complete range for you to work with.