An embedded system is a computer-based system built into a product to perform a specific, predefined function. It combines electronic hardware with programmed software and usually operates without the flexibility or visibility of a general-purpose computer.
How an Embedded System Works
Embedded systems generally follow an input-process-output model. Input data is received, processed according to stored instructions, and used to control an output.
| Stage | Function and example |
|---|---|
| Input | A sensor or user interface collects data, such as a thermostat measuring room temperature. |
| Process | A microcontroller or microprocessor compares the input with programmed instructions or a target value. |
| Output | An actuator or display produces a response, such as switching a heater on. |
| Feedback | In a closed-loop system, a sensor measures the result and returns new data so the response can be adjusted. |
For example, an automatic washing machine contains an embedded system. Sensors detect variables such as water level and temperature, the processor applies the selected program, and outputs control valves, the heater and the drum motor. The system is dedicated to controlling washing operations rather than running a wide range of unrelated applications.
| Embedded system | General-purpose computer |
|---|---|
| Designed for a specific function | Designed for many different tasks |
| Integrated into a product | Usually functions as the main product |
| Often operates automatically in real time | Usually depends on direct user control |
| Has limited, purpose-selected hardware and software | Supports broad software and hardware options |
A common misconception is that every electronic product is an embedded system. A simple torch with only a battery, switch and lamp has no programmable processing unit, so it is an electronic system but not an embedded system.
IB Exam Technique
For A3.4 Introduction to electronic systems (HL only), identify the input, processor and output in a named product. If asked to explain, show how information moves through the system and state whether feedback allows automatic adjustment; do not merely list components.