Building electronic projects that interact with the physical world is good fun. But when the devices you've built start to talk to each other, things really get interesting. The workbenches of hobbyists, hackers, and makers have become overrun with microcontrollers -- computers-on-a-chip that power homebrewed video games, robots, toys, and more. In this book, author Tom Igoe shows how to make these gadgets communicate. You'll get instructions for more than two-dozen simple projects that you can customize with your own designs.