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11.Oct.2024
What is an Embedded System?
What is an Embedded System?
An embedded system is a specialized computer system consisting of hardware and software designed to perform specific and specialized functions. Embedded systems are "embedded" because they don' t work individually; they are "embedded" within larger devices and electronic systems for controlling, monitoring, or automating tasks in industries like manufacturing, automotive, consumer electronics, and healthcare.
What are the Components of an Embedded System?
As mentioned, an embedded system combines hardware and software designed to carry out specific tasks.
Here are 3 major components of embedded systems:
- Hardware: The hardware is at the core of any embedded system, typically including microprocessors or microcontrollers, since they are designed for specific tasks, offering optimized performance and power consumption, also come along with a very compact size that embedded into devices or machines.
- Software and Firmware: The embedded system' s software consists of specialized programs that allow the system to function.
- Real-Time Operating System (RTOS): An RTOS is an operating system designed to respond to external events with minimal delay, making it crucial for systems that need real-time processing and rapid responses.
Besides the major hardware, here are some other important components of embedded systems:
- Sensors (Input): These devices receive data from the environment and convert physical inputs into electrical signals.
- Processors: They process the digital signals and manage data storage. Common processors include the CPU within a microcontroller or a microprocessor.
- Actuators (Output): Actuators convert electrical signals into physical actions, functioning as output devices to execute the actions determined by the data processor.
How Does an Embedded System Works?
The graphic below illustrates how an embedded system works and how the components interact with each other.
- Sensors gather data:
The system' s input devices (like sensors) collect environmental data. In ABS example, a speed sensor continuously monitors the wheel rotation. - Analog-to-digital converters:
A-D converters change an analog electrical signal into a digital one. - Input signals sent to the hardware (microcontroller or microprocessor):
The data from the sensors is converted into an electrical signal and sent to the microcontroller & microprocessor with memory & CPU, which processes the data - Digital-to-analog converters:
After processing the input data, D-A converters change the digital data from the processor into analog data. - Acuators (output devices) execute the actions:
Receiving the analog data, the output devices execute the demand or being triggered. In this case, if the microcontroller detects that a wheel is slowing down too quickly or is about to lock up, it automatically sends signal to hydraulic modulator, adjusting the braking pressure to prevent this.
Embedded systems can be categorized into four main types based on their performance, functional requirements, and real-time constraints. Here are the four types:
- Real-Time Embedded Systems: These systems must respond to events or data inputs within a strict time limit, often used in environments where timing is critical.
- Hard Real-time Systems: Must meet strict deadlines, such as aircraft control systems, pacemakers
- Soft Real-time Systems: For these systems, finishing the task is the top priority, whereas meeting the deadline is less critical, such as smart TVs.
- Standalone Embedded Systems: Operate independently and do not rely on a host system (such as a computer) to function. Examples include MP3 players, digital watches, and temperature sensors.
- Networked Embedded Systems: Connected to a network to communicate with other systems or devices. They are used to monitor and control devices remotely and exchange data across networks. Examples include smart home devices, IoT devices, and industrial IoT applications.
- Mobile Embedded Systems: These systems are found in portable devices such as smartphones, tablets, and wearable devices. They prioritize low power consumption while maintaining good processing performance.
Embedded System vs. Embedded Computer
While the terms embedded computer and embedded system are closely related and often used interchangeably, they are not exactly the same. Here's how they differ:
| Aspect | Embedded System | Embedded Computer |
|---|---|---|
| Definition | A complete system with hardware and software. | A computing unit designed for rugged and harsh environment. Serves as an essential component within a larger machine or system |
| Scope | The entire system (including sensors, actuators, etc.). | The computer itself (sometime part of an embedded system). |
| Complexity | Can be simple (microcontroller-based) or complex. | Generally more complex, often running an OS. |
| Components | Processor, sensors, actuators, power supply, software. | Processor, memory, I/O interfaces, OS. |
| Operating Systems | May use RTOS, firmware, or no OS (in simpler systems). | Typically runs Linux, Windows, or RTOS. |
| Examples | ABS in cars, smart thermostats, medical devices. | Industrial PCs, IoT gateways, AI edge devices. |
- Embedded Computer: This refers to the computing hardware—processor, memory, and I/O interfaces—inside an embedded system. It handles specific computing tasks within a larger system and usually includes a microprocessor or microcontroller.
- Embedded System: This includes the entire setup: hardware (including the embedded computer) and software (firmware), designed for specific tasks. It interacts with components like sensors, actuators, and power sources.
- Embedded Computer = The hardware (CPU, memory, interfaces).
- Embedded System = Hardware + software designed for specific functions.
Examples of Embedded Systems
Here are three examples of how embedded systems function in different domains:
Embedded Systems in car: Anti-Lock Braking Systems
In an ABS, embedded systems utilize sensors to continuously monitor the rotational speed of each wheel. When a potential lock-up is detected, the embedded control unit processes the data and adjusts the brake pressure through hydraulic actuators.
- Input: Wheel Speed Sensors
- Output: Hydraulic Modulator, Brake Actuators, Warning Light
Interactive Kiosks
Interactive kiosks are specialized embedded systems designed for user self-service. They feature touchscreens and integrate peripherals like printers, card readers, and scanners. Powered by compact, efficient hardware and an embedded operating system, kiosks process real-time inputs, manage transactions, and connect to networks for data exchange. These systems are widely used in retail, healthcare, and public services.
- Input: touchscreens, barcode scanners, card readers, RFID readers, cameras
- Outputs: displays (touchscreen or monitor), receipt printers, speakers for audio feedback
Fitness Trackers
Fitness trackers are specialized embedded systems designed to monitor various health metrics such as heart rate, steps, and sleep patterns. They utilize sensors to gather physical data and embedded software to process and analyze this information in real-time.
- Inputs: heart rate sensors, accelerometers, GPS, temperature sensors
- Outputs: displays (OLED or LCD), smartphone apps, vibration alerts
FAQ:
1. What is an embedded system?
An embedded system is a specialized computer system designed to perform specific, dedicated tasks within a larger system, often with real-time constraints.
2. What are the components of an embedded system?
Hardware, Software and Firmware, Real-Time Operating System (RTOS), Sensors, Processors, and Actuators.
3. What is a microprocessor?
A microprocessor is the central processing unit (CPU) of a computer that performs general-purpose computing tasks by executing instructions.
4. What is a microcontroller?
A microcontroller is an integrated circuit that contains a processor, memory, and input/output peripherals, optimized for controlling specific tasks in embedded systems.
5. What industries rely heavily on embedded systems?
Embedded systems are essential in industries such as automotive, healthcare, industrial automation, telecommunications, and consumer electronics.
6. What is the role of real-time operating systems (RTOS) in embedded systems?
An RTOS ensures that tasks are completed within strict time constraints, providing the responsiveness needed for real-time applications like industrial control and automotive safety systems.
7. Can an embedded system be updated or upgraded?
Yes, some embedded systems can be updated or upgraded through firmware updates, although many are designed to run without significant changes for long periods.
8. What are the future trends in embedded systems?
Future trends include the integration of artificial intelligence (AI), machine learning, and the Internet of Things (IoT), driving advancements in smart devices, automation, and connected infrastructure.
