An embedded system is a combination of computer hardware and software which can either be fixed in capability or can be programmable and it may be specifically designed for a particular function. An embedded system does not necessarily look like a computer, meaning it does not necessarily consists of a keyboard, mouse or monitor. However, it consists of a processor and software. As the word itself said, “embedded” means “built in” the system. In simpler terms, it means that it is a permanent part in a bigger system. An embedded system is expected to respond, monitor as well as control external environment using sensors and actuators.
So, basically what we are referring about embedding a computer; embedding a computer into an appliance and, that computer is not expected to be used for any general purpose computing. Since it is embedded into an appliance, it needs to interact with the external world and that is why it has got analog interfaces.
Let’s take a look at some common examples. The controller which is embedded in an elevator dictates the motor when to move the elevator to different floors, based on buttons that are pressed by the user. Moreover, a decoder which is embedded in a satellite television set-top box is used to read a signal from the dish and then it sends something to the TV which it can understand. Another familiar example is that of an automobile which contain a large number of microcontrollers and this is actually an embedded networked computing system. Embedded systems can in fact range from portable devices such as digital watches and MP3 players, to large stationary installations such as traffic lights, factory controllers, and very complex systems like hybrid vehicles, MRI, and avionics. It should also be noted that embedded systems control many of the common devices which are in use today, from card readers in hotel door locks to many controls in a car. They can be small too for example, an MP3 player or a digital camera and large large systems like traffic lights, airplane controls, or assembly line controllers in a factory.
Well, it should be emphasized that an embedded system is one which is exclusively designed to perform a specific function and it should not be confused to the general-purpose computer that we are used to which has the ability to perform multiple tasks. The program instructions which are written for embedded systems are referred to as firmware and they are stored in read-only memory or Flash memory chips. They run with limited computer hardware resources, that is, little memory, small or non-existent keyboard or screen.
1.)Can you please explain what does Real-Time Systems refer to?
2.)Can you please explain in detail how the surveillance system consists of an embedded system?
3.)Can you please give an overview about the programming aspect of embedded systems?
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