Although there are other ways to do this, [Rod] has decided to write up his method of using two Arduinos and the I2C protocol to expand an Arduino’s IO capacity. As seen in the picture above ...

But what can you do if you don’t have these tools on hand? [Andrew Moser] has a method that lets you pull it off with an Arduino and an LM339 quad comparator. The circuit works by feeding a ...

This method uses the tri-state logic capabilities of microcontrollers in order to gain efficiency over traditional multiplexing. Often, when it comes to your Arduino project,you never have enough ...