FIGURE 2-3 The Serial Monitor button
FIGURE 2-4 The Serial Monitor in the Arduino IDE You will see the messages from your Arduino Uno appear in your Serial Monitor. The Serial Monitor is a tool built into the Arduino IDE that lets you see the messages sent by the Arduino Uno using serial communication. You will find it a very useful tool in all of your adventures! When you are done with the Serial Monitor, you can just close the window. It may also close on its own when you upload a new sketch to your board. You can reopen the Serial Monitor to see any new messages.