Microcontroller circuits

A microcontroller is a small, self-contained computer built onto a single integrated circuit, combining a processor, memory and input/output connections in one device. Unlike a general-purpose processor that needs many supporting chips, a microcontroller can run a stored program and interact with the outside world largely on its own, which makes it ideal for embedding inside equipment. Microcontroller circuits use such a chip as the brain of a design, with the program in memory deciding how the hardware behaves.

A widely used family in hobby and educational electronics is the PIC microcontroller, made by Microchip, with popular parts such as the 16F84 and related devices. Other common chips include members of the 8051 family and Atmel microcontrollers. A typical circuit surrounds the chip with only a few essentials: a power supply, a clock source such as a crystal to set the operating speed, and connections to the switches, sensors, displays or driver stages it must control. The program is written on a computer and loaded into the chip's memory using a programmer.

Because the same hardware can perform very different tasks simply by changing its program, microcontrollers are extremely versatile. Projects range from flashing lights, timers and clocks to motor and servo controllers, sensor readers and instruments. The microcontroller handles timing, decision-making and communication, while external driver circuits manage higher currents. Collections of microcontroller circuits provide schematics and example code that show how a single programmable chip coordinates the inputs and outputs of a complete project.

Frequently asked questions

What is a microcontroller?

A single-chip computer that combines a processor, memory and input/output, able to run a stored program and control hardware on its own.

What is a PIC?

A popular family of microcontrollers made by Microchip, including widely used parts such as the 16F84, common in hobby projects.

Why are microcontrollers so versatile?

The same hardware can perform very different tasks simply by loading a different program into its memory.