Universal Serial Bus, developed by Ajay Bhatt, are specifications for setting up communication between external add on devices and the hard disk of the computer. USB devices include gadgets such as mice, keyboards, digital cameras, printers, media players, etc and they connect to the PC. Since the operating system is compatible with USB, the installation of the device drivers is fast and easy.
Fast Facts
Retailers sell approximately 2 billion USB devices every year. 6 billion is the total number of USB devices sold till today.
USB connector Features
Smart phones, PDAs and video game consoles also use USB connectors, not only PCs. Another function of the USB stick is that it can also be used as a power cord. Some companies wanted to focus on speed, so they researched and led the initiative to develop higher speeds of data transfer that resulted in greater speeds for the USB 2 specification. The USB 2 specification was released in 2000. It achieved speeds of 480Mbits/s, which was considered a new benchmark.
USB connector properties
USB connectors have certain properties that they are supposed to adhere to. These are:
•Durability: The USB connectors were changed into a robust design unlike previous connectors that were fragile.
•Compatibility: USB connectors have loose tolerance for compliant USB connectors in order to reduce incompatibilities. USB connectors also have 2-way communications possible.
•Utility: The USB connection cannot be made up side down, as the device will hook on only if the right connection is made.
USB connector Class
There are various types of USB classes depending on the type of gadgets such as:
•Audio, consisting of a speaker, microphone, a soundcard and MIDI.
•The communications and CDC control class consists of a modem, an Ethernet adapter or wi-fi.
•The Human Interface device consists of a keyboard, a mouse or a joystick.
•The mass storage class consists of a USB flash drive, a memory card reader, a digital audio player, a digital camera etc.
Uses of class specs
The main and most important usage of the USB mass storage device is the portable execution of software applications without installation.
USB connector Design
Hubs link USb systems and it has an asymmetric design. A USB gadget may consist of many sub devices, or a single USB device may consist of several functions, such as the webcam and audio functions. USB gadget communication is based on end points called pipes.
USB connector types
There are 4 types of USB connectors, namely, the Standard A, the Mini-A the Mini-B and the Standard B.
The Standard-A type of USB plug is flat and rectangular in shape. It carries both power and data. This plug is frequently seen on cables for permanent devices, such as one connecting a keyboard or mouse.
The Standard B type is square in shape, used to connect to portable devices, such as a printer.
The Mini-A connectors are usually used for On-The-Go (OTG) devices that need to connect to one another, rather than to a computer. Mini-A are small to suit the devices that are too small to offer a full-size type A port.
