The Microcontroller in a System

Microcontrollers do not function in isolation. As their name suggests they are designed to control other devices. The microcontroller can accept inputs from some devices and provide outputs to other devices within any given system. For example, a microcontroller may accept input from a switch and may send output to an LED. If the switch is pressed the microcontroller can be instructed to illuminate the LED.

The microcontroller is often part of a larger system. For example, the switch and LED may be part of a compact disc player in a car stereo system. When a microcontroller is part of a larger system it is often referred to as an embedded controller because it is embedded within the larger system.