Embedded systems: tiny computers hiding everywhere

By the end of this lesson

By the end you can say what an embedded system is, spot one in a device, and give its benefits and drawbacks in context.

Count the computers in your kitchen

Microwave, washing machine, fridge, kettle with temperature buttons, the oven timer. Each one hides a small computer that does exactly one job.

You never install apps on them, and you never think of them as computers. That's the point.

Definition

Embedded system

A computer system built into a larger device, with its own microprocessor (or microcontroller) and memory, designed to carry out one dedicated task (or a small set of related tasks). Its program is usually fixed and not changed by the user.

What's inside

Most embedded systems are built around a microcontroller: a single chip containing

a processor;
ROM (or flash) holding the fixed control program, often called firmware;
RAM for the current settings and readings;
input/output ports.

Inputs are often sensors and buttons; outputs are often actuators (motors, valves) and small displays.

One chip, one job. The program sits in ROM, so it's there every time you switch on.

Embedded or general-purpose?

Embedded system	General-purpose computer
inside a larger device	is the device
one dedicated task	runs any software you install
program fixed in ROM or flash	programs loaded from storage
e.g. car engine management, pacemaker, smart thermostat, traffic lights	e.g. laptop, desktop PC

Spot it

Multiple choiceQuestion 1 · Recall

One-line answerQuestion 2 · Recall

Fill in the blanksQuestion 3 · Apply

Answer the 3 questions above to continue.