Connecting Your Arduino to the Internet

Parts You'll Need for This Chapter

Arduino (Uno recommended)

USB cable

Arduino Ethernet shield


10kΩ resistor

TMP36 temperature sensor


220Ω resistors (×3)

150Ω resistor

Speaker or buzzer

Ethernet cable

Access to a wired router

Jumper wires



Code downloads, video, and other digital content for this chapter can be found at

In addition, all code can be found at on the Download Code tab. The code is in the chapter 14 download and individually named according to the names throughout the chapter.

This is it, the final frontier (and chapter). Short of launching your Arduino into space, connecting it to the Internet is probably the closest that you will get to making the whole world your playground. Internet connectivity, in general, is an extremely complex topic; you could easily write entire volumes of books about the best way to interface the Arduino with the “Internet of things,” as it is now often called. Because it is infeasible to cover the multitude of ways you can interface your Arduino with the web, this chapter focuses on imparting some knowledge with regard to how network connectivity works with your Arduino and how you can use the Arduino Ethernet shield to both serve up web pages and to broadcast data to the web. Specifically, you learn about traversing your network topology, ...

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