ICT Input and Output Devices

• Input and output devices explained as part of ICT
• Input devices are used to enter data into a computer
• There are two categories of input devices: manual and Direct Data Entry (DDE)

Manual Input Devices

• These devices need someone to enter data into them

Direct Data Entry (DDE) devices

• These devices enable data to be entered directly, without manual human input

Pointing Devices

• A mouse is a pointing device used with a computer that runs with a graphical user interface
• Moving the mouse on a flat surface will move the pointer on a screen
• Computer Mice provide a fast method of input, and they are intuitive to use
• Computer Mice can be easily damaged, and overuse may lead to repetitive strain injury, also needing a flat surface to operate
• Touchpads often accompany laptops, being a variation of a mouse for a pointing device
• Touchpads allow usage of one, two or more fingers for different functions
• A trackerball is stationary and does not need a surface to be moved on
• Trackerballs can be built into a computer and can be used by disabled people who do not have the freedom of movement to use other pointing devices
• Trackerballs can be difficult to use for applications that need fine control

Remote Controls

• They are small, handheld devices that operate equipment
• A remote control’s advantage is convenience
• Disadvantages are signal interference and blockage by objects

Joysticks

• Joysticks carry out the same tasks as a mouse
• Composed by a stick that pivots on a base where the top moves in any direction
• The advantage of joysticks are that they give the feeling of control when playing games
• Disadvantage is that it is difficult to control the fine movement of the pointer

Driving Wheel

• Designed for use in racing video games and driving simulators
• Driving Wheels allow control movement more accurately than a mouse or joystick
• They can provide simulated road assistance with force feedback
• Driving Wheels can only be used for one purpose; racing games
• Adding mechanical elements increases manufacturing costs

Touch Screens

• Touch Screens are intuitive and easy to use by just tapping an image
• Touch Screens are space-saving as input and output devices
• Touch Screens can be cost effective for shops and restaurants
• Disadvantages of touch screens are; not suitable for inputting large amounts of data, inaccurate for selecting small areas, and hygiene problems with lots of people touching the screen
• Touch Screens can determine where on the screen the user has touched and sends that information to the processor

Touch Screen Types

• Resistive screens are sensitive to pressure
• Capacitive screens care sensitive to static electricity

Scanners

• Scanners convert text, diagrams, and images into digital data for computer manipulation
• The advantages of scanners are; they produce high quality images, hard-copy material can be changed, scanned images can be imported into graphic applications
• Disadvantages of scanners are; a reduction in the quality of the image, and that scanned images take up a lot of space in storage

Cameras

• Digital cameras capture digital photographs that can be stored on a memory card or a hard disk and displayed on a screen
• The advantage of digital cameras are; that Pictures can be seen immediately and erased, digital images can be manipulated more readily than those on film, the image can be used in other electronic documents
• Disadvantages of digital cameras are; storage can fill up, memory cards become corrupted, and camera batteries can run out

Webcams

• Webcams are a special video camera with no storage, directly connecting to a computer
• Webcams can provide live video pictures when chatting with other people using applications and conduct video conferences
• Live Webcam images can be uploaded to a website so that people can see what is happening at a given site in real time

Microphones

• Microphones can be used to input sounds into a computer by converting sound waves into digital data
• Microphones can be used by people with disabilities, where using a normal input device is impossible
• Cheap Microphones do not give a true representation of the input sounds

Sensors

• Sensors are a device that detects and responds to some type on input from the environment like light, temperature and pressure
• Sensors are more reliable than a human because a human may forget to take readings.
• Sensor Readings are more accurate those taken by humans and can measure the input to where a human can not go
• Disadvantages of sensors are that digital sensors need a power source, requiring a power cut or battery, and if the sensors are left in a remote location, they may malfunction without the user knowing
• A sensor is a device which automatically inputs data into a computer system
• The data sensors input is constantly changing and can be measured

Key words for Sensors

• Data
• Automatic
• Measured
• Analogue
• Digital
• Analogue to Digital Converter (ADC)

Key words for CRT and the Smartphone

• Smartphone sensor: a sensor in a smartphone measures things movement, rotation, pressure and light intensity
• Pressure sensor: device that measures pressures and sends the data to a processor
• Light sensor: device that measures light intensity and sends the data to a processor
• Light pen: a specialized pen that works with a CRT monitor
• CRT monitor: monitor with a cathode ray tube; CRT was used in the traditional TV sets and monitors

An Example Control System

• A computer-controlled greenhouse might have a number of sensors and actuators
• Light sensors detect incoming light
• Temperature sensors detect temperatures
• Moisture sensors detect incoming moisture content
• Lights are actuators which act as illumination devices
• Heaters warm up the greenhouse as an actuator device
• Water pumps water systems
• Motors open the window if its too warm as actuators

Processes in automated system

• Check light sensor, if its dark, turn on the lights, if its not dark, turn off the lights
• Check temperature sensor, if it is too cold, turn on heater and use motor to close window, if it is too warm, turn off heater and use motor to open window
• Check the moisture sensor, if soil is too dry, turn on the water pump, if soil is too wet, turn off the water pump
• Go back to step 1 and repeat

Light pen

• Light pens are were light sensitive input devices previously used before the development of touch screens

More Key Words

• Graphics tablet: an input device consisting of a flat pad which the user 'draws' on or points at with a special light pen or stylus
• Stylus: a pen-shaped instrument whose tip position on a touch screen or tablet can be detected

MIDI keyboards

• It needs to be connected to the computer system using a MIDI interface, to translate the signal coming from the keyboard into electronic data

Direct Data Entry (DDE) and Associated Devices

• DDE is used when large amounts of similar data need to be entered, often in commercial or business applications:
• Magnetic stripe readers
• Chip and PIN readers
• RFID readers
• OCR and OMR
• Bar-code readers
• QR scanners

Magnetic Stripe Readers

• They are devices that read a magnetic stripe of a card, which contains data or to write to the stripe.
• It is simple, easy to use and inexpensive
• Entering data is fast – just swipe the card and there are no errors on inputting data
• Data on the card can be altered if necessary
• Disadvantages; very small storage capacity, data can be destroyed by magnetic field, and criminals can easily obtain card readers and writers.

CHIP and PIN Code Readers

• They are devices used to read data stored in the silicon chip of a debit card verify the personal identification number (PIN) entered using a numeric keypad.
• Advantages; Held information is more secure than magnetic stripes.
• Easy and the chip is harder to read.
• Advantages: You can can hold more information than on a mag stripe, may be brought to you, shop or restaurant.
• Disadvantages; you may forget or a viewer will see you punch it in, makes you careless

RFID readers

• A device use to read data stored on RFID tags.
• Uses radio waves to identify and track special tags attached to objects
• Can be read without authentication - causing security risks
• RFID Tag contains digital data that may be used for sending data via radio waves
• Can be affected, and have limit range

OCR (Optical Character Recognition)

• OCR scans a typewritten or printed document and translates the images of the characters into digital text that can be used on the computer
• The scanner is used to scan text on a document or piece of paper into the computer, then it examines, changes letters so it becomes editable
• OCR is a fast way of entering hard copy that can avoid typing errors to a high level standard of accuracy
• Generated text isn't reliable sometimes, may lead to incorrect storage and time consuming use checking its cost

OMR (Optical Mark Reading)

• Enables data/marked by a human making marks to selected
• The software can obtain information and has fast input.
• Scanners and computers needed to read it to be used

Bar Code Readers

• Device to read set of pararrel lines in contrasting colors (black and white)
• Quick and easy to get, they're simple

QR (Quick Response) Scanners

• Versatile to contain different types of data
• Codes can be read by devices by using software
• Device needed as some people don't know

Output Device: Monitor

• The main types are CRT, LCD and Touchscreen

Monitor: Resolution

• 3840 x 2160 is 2160p or 4K which is good quality
• 2560 x 1440 is 1440p or 2K and is good quality
• 1920 x 1080 is 1080p or Full HD maximum resolution
• 1280 x 720 is 720p HD minimum resolution
• 854 x 480 is 480p Standard definition
• 640 x 360 is 360p Normal website resolution
• 426 x 240 is 240p YouTube minimum video size

Multimedia Projectors

• A multimedia projector is a device that can project Output that is large
• It uses a computer
• Common for presentations

Devices: Printers/Platters

• Impact printers make contact with paper. Uses an inked ribbon against the paper by pressure w hammer/pins
• Types: Dot matrix use cintuous paper use
• Types: Line printers
• Types: Daisy wheel

Impact printers

• Non-impact printers do not use a striking devise to produce
• Types: Ink jet use
• Types laser use (filled w fine powder)

Laser Printers

• fast
• quite
• inexpensive

Laser Printer cons

• expensive
• colir ins't always precise

Inkjet Printer vs. Dot Matrix

INKJET printers

• Faster
• Quiter
• Chea

INKJET Printers cont

• Expensive link
• Difficulty to prevent and seal

dot matrix printers

• cheep
• continuous feed
• produces carbon copies & can print multi forms
• dont need quality

cons

• expensive
• noisy
• realivtley slow
• no color
• poor qualtiy

Actuators

• Devices, that move or control soem mechanics

• responds to controls

• hydraulic system/electric motors

• *Uses

• Open car doors

• Digital cameras

Sensors

• Pressure
• Water level
• Temperature
• Drum speed
• Balance === CONTROLS ====
• heat and light
• buzzzers

control device

• used as a sensor
• measure: - Temp-Pressure
• light

Actuators

are items that cause movement or a response in control systems. A sensor measures a change in the environment an in response the computer sends a signal to an actuator to cause a response to the change – for example, to open and close the windows in a greenhouse by switching on motors.