Book excerpt: Developers who design and program USB devices have a new resource in the fifth edition of USB Complete: The Developer's Guide. This edition adds an introduction to USB 3.1 and SuperSpeedPlus bus, which offers a 2x increase in bus speed over USB 3.0’s SuperSpeed. For designs that don't require USB 3.1’s capabilities, the book also covers USB 2.0 technology and applications. USB Complete Fifth Edition bridges the gap between the technical specifications and the real world of design and programming. Author Jan Axelson distills the fundamentals of the protocols and guides developers in choosing device hardware, deciding whether to target a USB class driver or another host driver, and writing device firmware and host applications. Example code in Visual C# shows how to detect and access USB devices and how to program and communicate with vendor-defined devices that use the human-interface-device (HID) class driver and Microsoft’s WinUSB driver. Also covered are how to use bus power, including new advanced power delivery capabilities, wireless communications for USB devices, and developing embedded hosts, including dual-role USB On-The-Go devices. Programmers and hardware designers can rely on USB Complete’s Fifth Edition to help get projects up and running quickly. Students and hobbyists will learn how to use the interface built into every PC. Instructors will find inspiration and guidance for class projects.