GCSE ICT WJEC Unit 1

GCSE ICT WJEC Unit 1

1. Data validation

   • Checking for errors
   • The computer checking data is:
     • Sensible
     • Within stated ranges
   • Types of check
     • Range checks

2. Data Logging and weather forecasting

   • Types
     • Analogue sensors
     • Digital sensors
     • Can convert analogue to digital
   • Weather forecasting
     • Data collected
       • Temperature / thermistor
         • Thermometer
       • Wind speed
         • Anemometer
       • Air pressure
         • Barometer
       • Air humidity
         • Hygrometer
       • Relative humidity
         • Wet and dry thermometers
       • Rainfall
         • Rain gauge
       • Wind direction
         • Wind / weather vane
       • Sunshine hours
         • Sunshine recorder

3. Control systems

   • Device control
     • One piece of equipment controlling the operation of equipment by sending to it.
     • Equipment is usually

4. Personal communication systems

   • Fibre optic cable
     • Works by transmitting data as a series of pulses along a thin glass fibre. One bundle of fibres is used to send messages and a second bundle carries messages in the opposite direction
     • Are good at transferring data because they are fast and do not suffer from interference like metal cables.
     • Broadband
       • Very high speed digital lines
     • A router is a special piece of hardware which co-ordinates the switching of messages between the computers and the rest of the internet
     • Broadband allows you to be on the phone whilst on the internet
   • Wireless media / Radiowaves
     • Microwaves
       • Mobile phones use microwaves. Ideal for linking computers in two separate buildings fairly near each other. Satellite systems also make use of microwaves.
     • Infra-red
       • Short range communications
       • Key freatures are
         • Robustness
         • Low cost
         • Low power
       • Examples
         • Wireless mouse / Keyboard
         • Link from a laptop computer to a printer
         • Wireless hands free for mobile phones in cars
     • Bluetooth
       • Can only travel short distances and line of sight and this limits their use
         • TV remote control
   • Mobile phones
     • Disadvantages
       • Signal cannot be recieved
       • Limit calls
         • Low battery
         • Low credits
       • Microwave radiation that comes from the phone can affect health
       • Users can build up large phone bills using internet service
       • Can be a nuisance is they ring at inconvenient times
       • Can be an incentive for theft
     • Used for
       • Speaking to other people
       • Testing.
         • Short message service
         • SMS
       • Photo / Picture messaging
       • Other services
       • M commerce
       • GPRS
       • Using Wireless Application Protocol systems
         • Email
         • Internet