Throughout this guidebook, we have spent some time talking about a few of the projects that you can execute with the help of your Arduino board. A few of these have required you to use a USB cord to help hook up to a computer so that you can download whatever code you want to use. Now we are going to take this a bit further and work on serial communication and how we can use this to figure out which sensors are working, whether our projects will make the right decisions, to change our variable values, and to control other movements.