USB Adapters Device Classes

There are several agreed upon USB common class specifications. One of the most basic is the Human Interface Device class that is used for the keyboard, mouse (pointing devices), and joysticks (game controllers). The HID class is also used for such things as monitor control, uninterruptable power supplies (UPS), and point of sale electronics like bar code readers, weighing devices, and magnetic-stripe readers.

Another very popular class is the USB mass-storage device. This is the one used by all thumb drives. The usb class is also used for external floppy drives, hard drives, and DVD writers. IPods and mp3 players can also use this USB driver to transfer music files back and forth. Cameras and the flip video also use this class so you can transfer pictures and files out of their memory.

Modems and network adapters are part of the USB communication-device class (CDC). The serial port adapters are also part of the CDC class. Camera and Scanners have their own specification called the USB still-image class. Printers have their own USB class. Speakers, microphones, and midi devices are part of the USB audio class. Web cams, digital camcorders, and video streaming devices are part of their own USB video class. Infrared devices use the IrDA (Infrared Data Association) USB class and allows these devices to exchange data as an IrDA bridge.

One of the more unusual classes is the Device Firmware Upgrade (DFU) class. This allows for a host PC to send patches and updates to a particular USB device. Another unusual one is the Content Security USB Class, which used for copy protection.