Most of the projects in this chapter rely on the standard libraries and do not require anything extra. The exception is the ultrasonic range finder project, which requires an Arduino board and an ultrasonic range finder sensor. The hardware is relatively cheap (under 10 dollars). You may also decide not to buy the hardware and still read the project to understand how serial communication takes place between two pieces of equipment.
In addition, you will also need to download and install the Arduino integrated development environment (IDE), the details of which will be discussed in the project itself.