Microcontrollers are computers that are imbedded in many electronic devices, such as cars, alarm clocks, VCRs, and much more. They are responsible for responding to particular programs, and are generally small, low-cost, and low-energy.
Your microwave, your car, your cellular telephone, your digital alarm clock, your VCR and many more widely used products utilize microcontrollers for optimal functionality. The items that use microcontrollers do so in order to be more user-friendly and efficient. Pretty much anything that has a digital LCD or LED screen uses a microcontroller, as do many products that do not have a digital read-out screen. Microcontrollers are not used on their own - they are embedded in other computers and machines (hence, the reason that these controllers are also referred to as "embedded"). The microcontrollers are responsible for controlling a particular action or feature for a device; a microcontroller controls one specific program. The program that a microcontroller runs is stored in read-only memory (ROM). The program that is stored in the microcontroller's ROM is generally unchanging, which is one of the reasons that microcontrollers are able to be so small and efficient.
Microcontrollers function by taking input from the device that they are in. For example, the microcontroller in a microwave is given input from the keypad. When you use the microwave keypad to select thirty second of high-power for your leftover pizza, that information is sent to the microcontroller for execution. The microcontroller has the purpose of turning the microwave's generator on and off, based on the selections you press on the keypad. In instances where it would be practical, microcontrollers are ruggedized so that they will work under the stress of environmental factors or rough treatment. Ruggedization is implemented in car engine microcontrollers. For a microcontroller to work well with a car engine, it has to be able to withstand extreme heat and cold, and it has to withstand the bumps and movements that are obviously going to occur when a car is driven.
Microcontrollers can run on a variety of different processors. In many cases, however, the most minimalist processors are used, since they are also the least expensive, and nothing more powerful is needed to fulfill the duties of the microcontroller. These minimalist processors are appropriately termed microcontroller chips or "microchips", and they are embedded CPUs. Microcontrollers are the worker bees of the computer world, doing their specialized jobs quietly and diligently for the good of the device. You may not have known that they were there, but they have been helping you out with your technological products for years.
