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Cambridge IGCSE0417

Microprocessor-controlled devices

Information Communication Technology 0417 Chapter Notes

What this chapter covers

Microprocessor-controlled devicesPotential health problems related to the prolonged use of IT equipment
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In this chapter

  1. 1What a smart device does
  2. 2Positive effects on lifestyle and leisure time
  3. 3Negative effects on people
  4. 4Security of data and connection
  5. 5Microprocessors in transport
  6. 6Repetitive strain injury (RSI)
  7. 7Back problems
  8. 8Eye problems and headaches
  9. 9Matching equipment to the issue it prevents

1. What a smart device does

A smart device can monitor and control other devices in the home. The controlling is what makes it smart.

A smart device is not the same as a smartphone. A smartphone is one way to reach it: devices can be turned on using a smartphone.

A benefit must belong to the smart device. Test each benefit: would it still be true if the device were not smart? If so, choose another.

Examiner insight

“Some candidates mixed up smart devices with smartphones and hence missed out the controlling elements that smart devices have.” “The most common correct answer related to smart fridges being able to order food.”

Worked example 12 marks

A washing machine turns itself off when the wash cycle has finished. A student says this is a benefit of the machine being a smart device. Explain why this is not a good answer, and state one benefit that does come from a device being smart.

  1. 1

    The answer would apply whether the machine was smart or not [1]

  2. 2

    A smart device can be turned on using a smartphone [1]

2. Positive effects on lifestyle and leisure time

With smart devices, people no longer have to continually monitor the devices. This allows them to do other things. They no longer have to stay at home while a device is being used.

Devices can be turned on / off from anywhere. This is more convenient using voice activated systems, and there is less manual work to do.

Smart devices can also increase the sense of security and give energy saving, which allows more money.

Examiner insight

“Most candidates were able to gain at least 1 mark for identifying increased leisure time.” “Few candidates were able to describe that a lot of tasks can be controlled when the person is away from their home.”

Worked example 16 marks

Smart devices can monitor and control other devices in the home. Describe the positive effects on lifestyle of using smart devices in the home.

  1. 1

    People no longer have to continually monitor the devices [1]

  2. 2

    Allows people to do other things [1]

  3. 3

    No longer have to stay at home whilst device is being used [1]

  4. 4

    Ability for devices to be turned on / off from anywhere [1]

  5. 5

    Increases the sense of security [1]

  6. 6

    Energy saving allowing more money [1]

3. Negative effects on people

Smart devices also have negative effects on the people who use them. They can make people lazy. People can become de-skilled. They can show over reliance on the devices.

There are marks for naming a valid smart device. Name the device, then describe what it does to the person, for example to their health or fitness.

An answer that starts "using microprocessor devices leads to..." names no device. The effect is then not clear, so it is difficult to gain any credit.

Examiner insight

“Quite a few candidates only described the issues and did not name any devices.” “For candidates who gave suitable examples of devices and then went on to describe the health or fitness issue relevant to the device, whether positive or negative, the maximum marks were achievable with many gaining good marks.”

Worked example 14 marks

Smart devices can monitor and control other devices in the home. Name one smart device and describe the negative effects of using smart devices on the people in the home.

  1. 1

    Names a valid smart device, for example a smart fridge [1]

  2. 2

    Smart devices can make people lazy [1]

  3. 3

    People can become de-skilled [1]

  4. 4

    People can show over reliance on the devices [1]

4. Security of data and connection

Smart devices can be connected to the internet. That brings disadvantages.

Hackers can take control of the devices. Malware is a risk. There is a lack of privacy.

If the controlling device is out of range, it will not connect. Expand the point: there is no way of knowing whether the device has switched on or off, which could cause problems.

Examiner insight

“The most common correct answers were based on hackers taking control of the devices, malware or lack of privacy.” “Few candidates were able to gain more than 4 marks for this question and gave little expansion to their answers.”

Worked example 14 marks

A family controls the heating, lights and door locks in their home over the internet, using a smartphone. Describe the disadvantages to the family of controlling the devices in this way.

  1. 1

    Hackers could take control of the devices [1]

  2. 2

    There is a lack of privacy [1]

  3. 3

    If the smartphone is out of range it will not connect to the devices [1]

  4. 4

    So there is no way of knowing whether a device has switched on or off, which could cause problems [1]

5. Microprocessors in transport

Microprocessors monitor and control transport too. A sensor sends data to the microprocessor all the time. The microprocessor compares the data with the pre-set value. When needed, it sends a signal to an actuator.

The sensor does not make decisions and does not make the change. An autonomous vehicle makes the change itself: it does not warn a driver.

A question that says evaluate wants advantages and disadvantages. For a driverless vehicle, write about the vehicle itself, not about drivers losing their jobs.

Examiner insight

“Weaker candidates explained that the sensor made the changes to the speed of the vehicle or that warnings were given to the driver to slow down or to speed up rather than being autonomous as stated in the question.” “There were issues with the key word evaluate which means to give advantages and disadvantages.”

Worked example 14 marks

A microprocessor keeps an autonomous vehicle at its set speed. The vehicle is travelling faster than the set speed. Describe how the system slows the vehicle.

  1. 1

    The sensor sends data to the microprocessor [1]

  2. 2

    The microprocessor compares the data with the pre-set value [1]

  3. 3

    The speed is higher than the pre-set value, so the microprocessor sends a signal to the actuator [1]

  4. 4

    The actuator slows the vehicle [1]

Recap

  • A smart device monitors and controls other devices. It is not a smartphone.
  • Positive: no need to monitor devices or stay at home, control from anywhere, security, energy saving.
  • Negative: people can become lazy, de-skilled and over reliant. Always name the device.
  • Internet control: hackers, malware, lack of privacy. Out of range means no way of knowing if a device is on or off.
  • Transport: the sensor sends data all the time, the microprocessor compares it with the pre-set value, then sends a signal to the actuator.
  • Evaluate means advantages and disadvantages. For a driverless vehicle, write about the vehicle, not about drivers losing jobs.

6. Repetitive strain injury (RSI)

Repetitive strain injury (RSI) is a health issue from prolonged use of IT equipment. Learn its causes and its prevention separately.

Causes: continuous use of a keyboard, continuously clicking the mouse button, holding the mouse tightly or incorrectly, and working in a cramped workspace.

Prevention: rest your fingers and hands regularly, use an ergonomic keyboard or mouse, use a wrist rest, and arrange the workspace so you are not cramped.

Examiner insight

“Some candidates gave answers that were the health issue and not the cause.” “Some candidates wrote that taking a break would be a prevention without expanding to say that whilst taking the break the fingers could be rested.”

Worked example 14 marks

One of the health issues is repetitive strain injury (RSI).

(i) State two possible causes of RSI.

(ii) State two possible strategies for the prevention of RSI.

  1. 1

    Cause: continuous use of a keyboard / typing for long periods of time [1]

  2. 2

    Cause: continuously clicking the mouse button [1]

  3. 3

    Prevention: rest your fingers / hands regularly [1]

  4. 4

    Prevention: use an ergonomic keyboard / mouse (or a wrist rest) [1]

7. Back problems

Back problems come from the way a person sits and where the equipment is placed.

Causes: working in a cramped workspace, not sitting upright in the chair (not sitting with good posture), and incorrect positioning of the computer screen.

Prevention: stretch your body or back regularly, use an adjustable or ergonomic chair, sit upright against the back rest, tilt the screen so the top of it is just below eye level, and use a footrest.

Examiner insight

“Some candidates wrote poor posture as the answer without expanding to say whilst sitting at the computer.” “Some candidates stated that taking a break would help prevent back ache without expanding their answer to say that during the break they must exercise or stretch.”

Worked example 14 marks

Back problems are a health issue.

(i) State two possible causes of back problems when using a computer.

(ii) State two possible strategies for the prevention of back problems when using a computer.

  1. 1

    Cause: not sitting upright in the chair / not sitting with good posture [1]

  2. 2

    Cause: incorrect positioning of the computer screen (or a cramped workspace) [1]

  3. 3

    Prevention: stretch your body / back regularly / take exercise [1]

  4. 4

    Prevention: use an adjustable / ergonomic chair (or a footrest) [1]

8. Eye problems and headaches

Eye problems and headaches come from looking at a screen. Give the issue itself: eye strain, headache, dry eyes.

Causes: staring at a screen for a long period of time, and sitting too close to the screen.

Prevention: use an anti-glare screen, make sure the screen is free from dust and dirt, and reduce the screen brightness to match the room brightness.

Examiner insight

“Many referred to health issues which were clearly not related to RSI such as eye strain.” “In previous sessions the Examiners have allowed take breaks and lowering the brightness of the screen, but both these answers are subjective therefore nowadays we only allow reduce the brightness to match the room brightness to gain the mark.”

Worked example 14 marks

State the health issue that is most likely to be caused by the following. Your answers must be different.

Prolonged clicking on the mouse button

Staring at a computer screen for a long period of time

Sitting too close to the computer screen

Not using a foot rest

  1. 1

    Prolonged clicking on the mouse button: RSI [1]

  2. 2

    Staring at a computer screen: eye strain (or dry eyes, neck ache) [1]

  3. 3

    Sitting too close to the screen: headache [1]

  4. 4

    Not using a foot rest: back ache (or DVT, foot cramp) [1]

9. Matching equipment to the issue it prevents

A question may name a piece of equipment and ask which health issue it prevents. Use the generic name: an ergonomic keyboard prevents RSI, and an ergonomic chair prevents back or neck problems.

The issues in a list must be different from each other. Health issues are RSI, back problems, eye problems and headaches. Electrocution and trip hazards are safety issues, not health issues.

Examiner insight

“As in previous years some candidates mixed up health issues and safety issues.” “There are also lots of answers that still include comfortable chairs rather than ergonomic chairs.”

Worked example 14 marks

State the health issue that is prevented by each of the following. Your answers must be different.

Using an ergonomic keyboard

Using an ergonomic chair

Making sure the computer screen is free from dust and dirt

Using an anti-glare computer screen

  1. 1

    Ergonomic keyboard: RSI [1]

  2. 2

    Ergonomic chair: back / neck problems [1]

  3. 3

    Screen free from dust and dirt: eye strain (or headache) [1]

  4. 4

    Anti-glare screen: headaches (or eye strain), different from the line above [1]

Recap

  • Health issues: RSI, back problems, eye problems, headaches.
  • RSI causes: continuous keyboard use, continuous mouse clicking. Prevention: rest fingers, ergonomic keyboard, wrist rest.
  • Back causes: not sitting upright, wrongly placed screen. Prevention: stretch regularly, adjustable chair, footrest.
  • Eye and headache causes: staring at the screen, sitting too close. Prevention: anti-glare screen, clean screen, brightness matched to the room.
  • Say ergonomic, not comfortable. Give a cause when asked for a cause and a strategy when asked for a strategy.
  • Health is not safety: no electrocution or trip hazards.

End-of-chapter exercise

Test yourself on the whole chapter. Work through these before moving on.

  1. State what a smart device in the home can do to other devices.1 mark
  2. State one thing a smart fridge can do that a fridge that is not smart cannot do.1 mark
  3. A dishwasher stops when its cycle ends. A student says this is a benefit of a smart device. Give a reason why this answer earns no mark, and state one benefit that does come from a device being smart.2 marks
  4. State two disadvantages of connecting the smart devices in a home to the internet.2 marks
  5. A man controls his lights from his phone. His phone is out of range. Describe the problem this causes.2 marks
  6. Name one smart device in the home and describe one negative effect of using it on a person.2 marks
  7. A student answers a question on health and fitness with "Using microprocessor devices leads to unhealthy lives." Explain why this answer earns no credit.2 marks
  8. Describe two positive effects on lifestyle of using smart devices in the home. Expand each point.4 marks
  9. An autonomous delivery van has no driver. A proximity sensor measures the distance to the vehicle in front. A microprocessor keeps the van at least a set distance behind that vehicle. A student writes: "When the van gets too close, the sensor sends data to the microprocessor. The sensor decides that the van is too close. A warning is given to the driver to slow down." (a) Identify the three mistakes in the student's answer. (b) Describe how the system slows the van when it is too close.6 marks
  10. Amara works away from home for a week at a time, often in places where her smartphone has no connection. At home she has smart heating, a smart door lock and a smart fridge. All three are connected to the internet and she controls them from her smartphone. Evaluate the effects on Amara of using these smart devices. Name the device in each point.8 marks
  11. State what the letters RSI stand for.1 mark
  12. State one possible cause of RSI.1 mark
  13. State the health issue most likely to be caused by prolonged clicking on a mouse button.1 mark
  14. State two strategies for the prevention of RSI.2 marks
  15. An office worker is told to take a break from typing every hour. Describe how the break helps to prevent RSI.2 marks
  16. A student works with the laptop screen set very low and slouches in the chair. State the health issue this is likely to cause and one cause from the description.2 marks
  17. State two strategies for the prevention of back problems when using a computer.2 marks
  18. A designer stares at a screen for hours and sits very close to it. State two different health issues this could cause.2 marks
  19. A gamer plays for five hours without stopping. She clicks the mouse button continuously, stares at the screen the whole time, sits very close to the screen and has no footrest. (a) State four different health issues she could get. Give the cause of each from the description. [4] (b) She buys an ergonomic mouse and an ergonomic keyboard. She says two of her health issues are now prevented. Explain why she is wrong. [2]6 marks
  20. A student wrote the six answers below. Each line is worth 1 mark. For each line, state whether it earns the mark. If it does not, give the reason and an answer that would earn it. 1. Cause of RSI: pain in the wrists 2. Prevention of RSI: use an ergonomic keyboard 3. A second prevention of RSI: use an ergonomic mouse 4. Cause of back problems: poor posture 5. Prevention of back problems: take a break 6. Cause of headaches: use an anti-glare screen6 marks

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