GCSE – Information and Communication GCSE – Information and Communication Technology – New SpecificationTechnology – New Specification

Computer Control – Computer Control –

Lesson 3Lesson 3

The Big PictureThe Big PictureYou are studying for the GCSE short course in ICT – to succeed you need to complete the controlled assessments and some theory unitsLearning ObjectivesLearning Objectives• Be able to understand the process of data logging• Know the different types of sensor and suitable uses for them• Be able to write a sequence of instructions to control a screen image orexternal device appropriately• To be able to discuss the use of ICT to control and monitor areas of everyday living such as:electronic toys, games, central heating systems, burglar alarms, smart meters, security systems, automatic doors, traffic control, systems, car parking systems, greenhouse control systems and robotics, simulation (for example flight or driving)Learning OutcomesLearning Outcomes• To be able to explain how and why we use Data-logging.• To know what the different sensors could be used for and explain why they are suitable.• To know how to apply simple programming sequences in order to control a simple external device or screen-image• To be able to successfully apply knowledge of control technology to everyday devices and situations.Success CriteriaSuccess Criteria• Suitable definitions and examples in the exercise book

InstructionsWorking singly or in pairs, using the materials in this PowerPoint, your Folens book (Pages 55 to 59) and the “Teach-ICT” website – construct an information leaflet about “Computer Control” and “Data Logging”

Extension Work

•Answer Questions 1 and 2 (page 56)

•Answer Questions 1, 2 and 3 (page 59)

Homework

• Complete any notes required and finish the questions

Hand in for your next lesson

The advantages of Computer Control:•little human interaction is required – for businesses this has implications about the number of people who may be required to work in a factory for instance•24/7 – The process can continue 24 hours a day, every day, which means that a factory can be used more efficiently•any problems are responded to immediately and automatically•readings can be taken in dangerous environments without endangering people.

The Disadvantages of Computer Control:•companies may have to purchase and install expensive equipment and computer hardware•there may be an increase in unemployment and some deskilling of the workforce generally•some problems may require an element of human interaction.

Computer Control – Advantages and Disadvantages

Computer Control

0 1 2 3 4 50 0 0 0 0 0

• A computer uses the following control port to monitor and control a household security system

Output bits0 - alarm light

1 - motor to close shutters 2 - siren

Input bit3 - sensor on front door4 - pressure mat

1. If the burglar stands on the pressure mat an alarm light would come on.2. If a burglar opens the front door the siren would come on 3. If the burglar stands on the pressure mat and opens the front door the alarm light would come on, the siren would come on and the window shutters would close.

All the bits are set to zero but if the input bits are set to one the corresponding output bits would also be set to1 Work through the examples in your workbook!

One way of representing control environments is to use flow-charts. In most of your revision guides this is the way that they will be represented:

A control system is used to control the drinks chiller in a supermarket. It is used in this way because we can then minimise the amount of human intervention in managing the system. In this system the optimum temperature that the chiller needs to be kept at is 5°C, although it will still keep the drinks in good condition if it is set to at least 1°C.

Please arrange the control sequences in the correct order, by dragging the text boxes into the correct symbol:

START

YES

YES

NO

NO

Read the temperature in the drinks chiller

Is the temperature less than 5°C?

Is the temperature greater than 1°C?

Turn on the chiller unit

Turn off the chiller unit

Control System (using a flow chart) - Example

This is the process of collecting data automatically using devices called sensors.

Within the school environment, it can be used for science lessons for taking repetitive readings or for taking readings that need to be taken over a long period of time.

It can also be used for instance in the geography lessons to take weather readings remotely.

Data Logging – What is it?

There are many reasons for using data logging

• Readings may be taken automatically• Readings can be taken over a long time (the logging period)• It is possible to specify how often readings are taken – this is called the logging interval.• Sensors can be placed in remote locations where it may be too dangerous for a human to take the reading – this can even be done using wireless technologies and satellite communication.• Once data has been read, it may be stored on a computer, where it may be processed.• It is possible to easily analyse the data using a computer – you can use statistical functions on spreadsheets and also it is possible to graph the data.

Data Logging – Advantages

There are many different types of sensors

• Temperature/Heat Sensors – called thermistors• Light Sensors• Sound Sensors• Pressure Sensors• Humidity Sensors• Passive Infra-Red Sensors (PIRs)

Read page 55 of the book to see how these different sensors may be used.

Data Logging – Sensors

There are two ways data may be sent to the computer

• Using direct connection with data cables connecting the computer to the data logger • Wireless technologies (Most often the technology used here is Bluetooth)

What is Bluetooth?

Bluetooth is an open wireless technology standard for exchanging data over short distances (using short wavelength radio transmissions) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security.

Data Logging – How is data sent to the computer?

There are a few disadvantages to data logging:

• There can be an over-reliance on equipment – it can malfunction – which may give false readings• The initial purchase cost of the equipment can be very high

Data Logging – Disadvantages

Internet ResourcesUse the Teach-ICT Website –

www.teach-ict.comIn the Key Stage 4 Section – click on GCSE ICT – then

OLD RESOURCES and choose All GCSE Topics

Under the Software tab, click on Data LoggingUse the Theory Notes and the Exam PracticeThenUnder the Software tab, click on ControlUse the Theory Notes and the Exam PracticeThenUnder the Software tab, click on RoboticsUse the Theory Notes and the Exam Practice

Hodder Book References

Extension Activities

• Read Pages 40 to 43

• Answer question 7 (Page 47)