CHAPTER 2

• Input device


  A device that is used to key in data to a computer
• Keyboards


  • They usually input text, numbers, letters
  • The first six alphabets are usually QWERTY
• Numeric keypads


  • They only contain numbers 0-9
• Ergonomic keyboards


  • They are designed to reduce health risks like carpal tunnel syndrome and repetitive strain injury
• Concept keyboards


  • They are used to repeat the same phrases and icons over and over
• Pointer devices


  • Touchpad
  • Trackball
  • Mouse
• Remote control


  A device that controls another device using an infrared signal
• Pointer devices


  • Joysticks
• Joysticks


  They are normally only used in gaming such as flight simulators or arcade games
• Sensors


  Devices that sense data and input it into the computer in a way the computer can understand
• Analog data


  Non-binary data that sensors understand
• Analog-digital converter (ADC)


  A device that converts analog data into digital data that the computer can understand
• Sensors


  • Temperature sensors
  • Humidity sensors
  • Pressure sensors
• Advantages of sensors


  • They are more quick and accurate than humans
  • They can work 24/7 without needing shifts
  • They can work in dangerous places without risk to humans
• Disadvantages of sensors


  • They are expensive to set up and maintain
  • If faulty, they can give fake readings
• Direct data entry devices

  • Magnetic strip readers
  • Contactless card readers
  • Chip and pin readers
  • RFID readers
  • Magnetic ink readers
  • Optical mark readers
  • Optical character readers
  • Barcode readers
  • QR code readers
• Output device


  A device that allows data to be output from a computer
• Actuators


  Devices that take digital signals from a computer and use them to operate other devices
• Actuators


  • Buzzers
  • Timers
  • Heaters
  • Motors
• Control applications


  Applications that take data from sensors and convert it into real-world outcomes and consequences
• A device that outputs sound is a speaker
• A device that inputs pins is a numeric keypad
• A device that outputs solid objects is a 3D printer
• A device that is both an input and output device is a touchscreen