Our first project will be creating an electronic die. While regular dice
display their results using one to six dots, ours will use LEDs instead.
For our first experiments, a single LED has been sufficient, but for
the dice we need more than one. You need to connect several external
LEDs to the Arduino. Because you cannot attach them all directly to
the Arduino, you’ll learn how to work with breadboards. Also, you need
a button that rolls the dice, so you’ll learn how to work with pushbuttons,
too. To connect pushbuttons and LEDs to the Arduino, you need
another important electronic part: the resistor. So, at the end of the
chapter, you’ll have many new tools in your toolbox.