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Explain why responsiveness in real time is the critical difference between embedded systems and other software systems.

Identify possible stimuli and the expected responses for an embedded system that controls a home refrigerator or a domestic washing machine.

What are the commonly used architectural patterns in real-time systems and when are they used?

Show how the Environmental Control pattern could be used as the basis of the design of a system to control the temperature in a greenhouse. The temperature should be between 10 and 30 degrees Celsius. If it falls below 10 degrees, the heating system should be switched on; if it goes above 30 , the windows should be automatically opened.

Design a process architecture for an environmental monitoring system that collects data from a set of air quality sensors situated around a city. There are 5000 sensors organized into 100 neighborhoods. Each sensor must be interrogated four times per second. When more than \(30 \%\) of the sensors in a particular neighborhood indicate that the air quality is below an acceptable level, local warning lights are activated. All sensors return the readings to a central computer, which generates reports every 15 minutes on the air quality in the city.

With the help of examples, define what a real-time operating system is. Explain how it is different from a conventional operating system. What are the components included in real-time operating systems and what are their responsibilities?