What is a microcontroller?

It is essentially a small computer. A comparison of a typical microcontroller with a typical desktop is shown in the following table:

	Atmega16	Typical Desktop
Clock frequency	16MHz	3GHz
CPU Data size	8 bits	32 bits
RAM	1kB	1GB
ROM	16kB	160GB
I/O	32 pins	Keyboard, monitor
Power Consumption	20mW	65W

Why use a microcontroller?

§  It is programmable. It is fun!

§  A code (typically written in C) decides what it does

§  Easier to write a code than design and make a custom circuit for complex jobs

§  e.g. In a micro-mouse, a single microcontroller controls the motors, finds distance from the walls, explores and solves the maze

§  The same microcontroller can be used in hundreds of applications

§  A glimpse of the overwhelming potential of a chip as small as a microcontroller can be seen on the Cornell Website that documents hundreds of projects on based on AVR Microcontrollers alone!

The AVR Microcontroller

There are plenty of microcontroller families available, each having its own special feature or convenience. However, in general, all microcontroller families have certain common features like a Serial Communication unit, and ADC (Analog to Digital Unit), general purpose Port pins etc. Commonly used microcontroller families are - 8051, PIC, AVR, MSP430, ARM etc.

A very useful guide on how to choose a microcontroller can be found on this Instructable. In this section, we discuss and demonstrate the usage of AVR Microcontrolles. Why AVR? They are cheap, extremely easy to use, fast and have loads of cool features.

Typical features of ATMega16

Typical features of ATMega16, an AVR Family Microcontroller are:

§  16 KB Flash memory

§  1 KB of SRAM

§  Up to 16 MHz clock

§  Four 8-bit I/O ports

§  ADC, Timers, Serial Interface etc

§  40 pin DIP, operates at 5V

CV-AVR tutorial:-