This guide was first published on Mar 28, 2014. It was last
updated on Mar 28, 2014.
This page (Overview) was last updated on May 19, 2019.
Pins are precious in the microcontroller world. How many times have you needed just one more pin? Sure, you could step up to a Mega and get a whole bunch more, but what if you really just need one or two? The DS2413 breakout board is the perfect solution. Each DS2413 breakout has 2 open drain GPIO pins and a 1-Wire interface. Just one of these boards will give you 2 pins for the price of one. But you can keep expanding from there.
You can put as many of these boards as you want on the the 1-wire bus and still control all of them with just one Arduino pin. Each chip has a 48-bit unique address, which means (in theory*) you could have as many as 2 * 2^48 pins controlled by just one Arduino pin! What could you control with 562 trillion pins?
* In practice, you would run out of Arduino memory long before that. But it's fun to imagine!