Embedded system

An embedded system is a computer that has been built to solve only a few very specific problems and is not easily changed.^[1] The word embedded means it is built into the system. It is a permanent part in a bigger system. It usually does not look like a computer, often no keyboard or monitor or mouse. But like any computer it has a processor, software, input and output.

For example, the controller embedded in an elevator tells the motor to move the elevator to different floors, based on buttons that are pushed. A decoder is embedded in a satellite television set-top box to read a signal from the dish and send something that a TV understands. Often this type of system must do its work in a specific amount of time. This is called real-time computing. If a set-top box got interrupted to do another task, you would see a bad picture on the TV, for example. A general purpose computer will often have short pauses while it does something else, it is not real-time.

Embedded systems control many of the common devices such as card readers in hotel door locks or several things in a car. They can control small things like an MP3 player or a digital camera, and large things like traffic light systems, airplanes, or assembly lines in a factory.

1. ↑ Michael Barr. "Embedded Systems Glossary". Netrino Technical Library. Retrieved 2007-04-21.