(!Ch3) USBs

• A USB is a form of serial data transmission, which is the industry standard for connecting devices to a computer.
• When a USB is connected, the computer automatically detects and recognises the device, and the appropriate device driver is loaded
• Connections only fit one way, preventing incorrect connections and USBs are backwards compatible
• They can support different transmission rates, and USB protocol notifies the transmitter to re-transmit if errors are made
• No need for external power source as the cable has 5V. It is easy to add more USB ports by using USB hubs
• Standard USB only supports a maximum cable length of 5m, beyond that, hubs are needed
• Very early USB standards may not be supported by new computers
• Slow data transfer rate compared with others, such as Ethernet
• USB-C uses a symmetrical 24-pin connector which means it will fit into a port either way up
• Advantages of USB-C:

  • Much smaller and thinner
  • Offers a 20V connectivity which means full size devices can be charged
  • Can support 4K video delivery
  • Backwards compatible if adaptor used