An embedded system is a combination of hardware and software that can be programmed or has fixed capabilities. An embedded system may be a standalone unit or a component of a larger system. It is primarily intended for a particular purpose or functions within of a bigger system. An embedded system that can only detect smoke, for instance, is a common example.
In this article, we will go over the basic structure and features of an Embedded System in order to better grasp what an Embedded System is, as well as list the many types of Embedded Systems and provide some real-world examples.
Basic Structure of an Embedded System
Sensor: The physical quantity is measured, and it is then transformed into an electrical signal that can be read by a viewer or by any electronic device, such as an A/D converter.
A/D Converter: The analog signal sent by the sensor is transformed into a digital signal using an analog-to-digital converter.
Processing unit: Data is processed by micro-processors or micro-controllers to determine the actuators output and even store some of this data in memory.
D/A Converter: The digital data provided by the processor is converted to analog data by a digital-to-analog converter.
Actuator: Receives the command as an analog signal, and transforms it into outside world actions, like movement, heat, sound…
Memory: Separate unit needed to store data or even programs that needed for the autonomous functioning of the embedded system.
Energy source: In all embedded systems, an energy source is need. It can be a component from the system itself (battery, capacitor …).
Energy converter: The received or onboard electricity needs to be converted for the level required by the processing unit and actuators.
Characteristics of an Embedded System
Important characteristics of an embedded system include the following:
Single-functioned: An embedded system typically carries out a specific task and repeatedly repeats it. An example might be: A pager always works as a pager.
Constrained: Design metrics are tightly limited in all computing systems, but they might be particularly so in embedded systems. Design metrics are a way to gauge an implementation’s cost, size, power, and other characteristics. It needs to be small enough to fit on a single chip, fast enough to process data in real time, and power-efficient enough to prolong battery life.
Reactive and real-time: Many embedded systems have to constantly respond to changes in their environment and calculate specific results instantly. For example, a cruise control system in an aircraft continuously analyzes and responds to speed, altitude and air sensors. It must repeatedly calculate pitch and power within a set amount of time; if the computation is delayed, the aircraft may be harder to control.
Memory: Since its software is typically embedded in ROM, it must have a memory.
Input/Output: It must have peripherals that are connected in order to link input and output devices.
Hardware/Software: For greater functionality and flexibility, software is used. Hardware is employed for security and performance.
Types of Embedded Systems
There are a few fundamental types of embedded systems, and each has unique functional needs. As follows:
Autonomous Embedded Systems: These systems are independent from the host system. Similar to every embedded system, they carry out a certain function. In contrast to other embedded systems, they are not always a part of a host system. An illustration of this would be a calculator or MP3 player.
Networked embedded systems: They have a network connection and send output to other systems. Point of sale systems and home security systems are a couple of examples.
Real-time embedded systems: They give the desired result in a predetermined amount of time. They frequently perform time-sensitive jobs, making them useful in the medical, industrial, and military fields. An illustration of this type would be a traffic control system.
- Ground Vehicles
- Aquatic Vehicles
- Commercial and Industrial Robots
- Dialysis Machines
- Infusion Pumps
- Cardiac Monitor
- Engine & Battery Control
- Ignition System
- Brake and direction System
- Equipment monitoring
- Traffic monitoring
- Multimedia (TV, DVD, …)
- Alarm system
- Air Conditioning
Military & Industry
- Nuclear Reactors
- Space Stations
- Autonomous factories