What is a microcontroller?

• A microcontroller is a computer. All computers — whether we are talking about ersonal desktop computers, large computers used in companies or a microcontroller have several things in common:
• All computers have a CPU (central processing unit) that executes programs.
• The computer has some RAM (random-access memory) where it can store “variables.”
• And the computer has some input and output devices so it can talk to people. On your desktop machine, the keyboard and mouse are input devices and the monitor and printer are output devices.
• The desktop computer you are using is a “general purpose computer” that can run any of thousands of programs. Microcontrollers are “special purpose computers.” Microcontrollers do one thing well. There are a number of other common characteristics that define microcontrollers. If a computer matches a majority of these characteristics, then you can call it a “microcontroller.
• Microcontrollers are “embedded” inside some other device (often a consumer product) so that they can control the features or actions of the product. Another name for a microcontroller, therefore, is “embedded controller.”
• A microcontroller is often small and low cost. The components are chosen to minimize size and to be as inexpensive as possible.