Project PDA

Connectivity might be:

• Infrared
• Bluetooth
• PC synchronisation (ActiveSync)
• Docking unit
• Cable connectivity (USB)

While many earlier PDAs connected via serial ports or other proprietary format, many today connect via USB cable. This served primarily to connect to a computer, and few, if any PDAs were able to connect to each other out of the box using cables, as USB requires one machine to act as a host - functionality which was not often planned. Some PDAs were able to connect to the internet, either by means of one of these cables, or by using an extension card with an ethernet port/RJ-45 adaptor.

USB port is any socket on a personal computer or peripheral device into which a USB cable is plugged.

Universal Serial Bus

Universal Serial Bus (USB) is a serial bus standard to interface devices. It was designed for computers such as PCs and the Apple Macintosh, but its popularity has prompted it to also become commonplace on video game consoles, PDAs, portable dvd and media players, cellphonesand even devices such as televisions, home stereo equipment (e.g., mp3 players), car stereos and portable memory devices.

The radio spectrum-based USB implementation is known as Wireless USB.

The most used device classes (grouped by assigned class ID) are:

• 0x00 : Reserved value - used in the device descriptor to signify that the interface descriptor holds the device class identifier for each interface.
• 0x01 : USB audio device class, sound card-like devices.
• 0x02 : USB communications device class used for modems, network cards, ISDN connections, Fax.
• 0x03 : USB human interface device class ("HID"), keyboards, mice, etc.
• 0x06 : Still image capture device class, identical to the Picture Transfer Protocol as used across USB
• 0x07 : USB printer device class, printer-like devices.
• 0x08 : USB mass storage device class used for flash drives, portable hard drives, memory card readers, digital cameras, digital audio players etc. This device class presents the device as a block device (almost always used to store a file system).
• 0x09 : USB hubs.
• 0x0E : USB video device class, webcam-like devices, motion image capture devices.
• 0xE0 : Wireless controllers, for example Bluetooth dongles.
• 0xFF : Custom device class - used to establish that a device or interface does not support any standard device class and requires custom drivers.