A microcontroller is a compact microcomputer designed to govern the operation of embedded systems in motor vehicles, robots, office machines, complex medical devices, mobile radio transceivers, vending machines, home appliances, and various other devices. A typical microcontroller includes a processor, memory, and peripherals. The simplest microcontrollers facilitate the operation of the electromechanical systems found in everyday convenience items. Originally, such use was confined to large machines such as furnaces and automobile engines to optimize efficiency and performance. In recent years, microcontrollers have found their way into common items such as ovens, refrigerators, toasters, clock radios, and lawn watering systems. Microcomputers are also common in office machines such as photocopiers, scanners, fax machines, and printers. The most sophisticated microcontrollers perform critical functions in aircraft, spacecraft, ocean-going vessels, life-support systems, and robots of all kinds. Medical technology offers especially promising future roles. For example, a microcontroller might regulate the operation of an artificial heart, artificial kidney, or other artificial body organ. Microcomputers can also function with prosthetic devices (artificial limbs). A few medical-science futurists have suggested that mute patients might someday be able, in effect, to speak out loud by thinking of the words they want to utter, while a microcontroller governs the production of audio signals to drive an amplifier and loudspeaker. Microcomputers enjoy immense popularity among electronics hobbyists and experimenters. Perhaps the most widely known and used of these devices belong to the PIC family, manufactured by Microchip Technology, Inc. of Chandler, Arizona. All devices in the PIC family come with a wide variety of development tools, are easy to find, remain relatively inexpensive, and have excellent documentation