By Brennon Williams
An Introduction to
Microcontrollers:
The Good, the Bad,
and the Ugly
Microcontrollers are the driving component behind nearly every digital device.
They control everything from the cell phone in your pocket to the NASA
satellites hurling above Earth at a speed of over 17,000 miles per hour. What
microcontrollers do is process inputs from the real world — such as a
temperature sensor — and then respond as programmed by flipping a series of
switches on or off, as with a light emitting diode (LED).
Microcontrollers are sometimes referred to as “single chip computers.” This is because that’s exactly what they are — entire computers itting on a single integrated circuit. Much like your Mac or PC, they use binary code (zeroes
and ones) to store data. Also like your computer, they have
a hard disk of sorts. It is called Flash memory and it retains
information even when the device is off.
There are other forms of memory such as Random
Access Memory (RAM). However, when your
microcontroller is turned off, all data stored in RAM is lost.
Regardless of memory and power, the main thing to
note is that microcontrollers are designed to react to input
from their environment as opposed to from a user.
Microcontrollers are often confused with
microprocessors. Microprocessors are typically much higher
performing, and are used in desktop and laptop computers.
Unlike their heavy-duty cousin, microcontrollers have the
unique ability to use incredibly small amounts of electricity
in milliwatts or microwatts. Many microcontrollers can go
into a sleep mode (such as when waiting for someone to
push a button) that can bring the power usage down to
nanowatts, making them invaluable for devices that need to
have a long battery life. Microcontrollers can also have
clock rates as low as 4 kHz. By contrast, my Apple MacBook
operates at 2. 16 GHz, dwarfing the microcontroller in
comparison.
