Embedded Systems – What Are They and How Do They Work

Embedded Systems – What Are They and How Do They Work

An embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints.

It is embedded as part of a complete device often including hardware and mechanical parts. Embedded systems control many devices in common use today.

This article provides an in-depth overview of embedded systems – explaining fundamentals like what an embedded system is, how it works, its components, communication protocols, applications, benefits, and design methodology.

Table of Contents

What is an Embedded System?

An embedded system is a computer system with a dedicated function within a larger electrical or mechanical system. It is embedded as part of a complete device often including hardware and mechanical parts.

Embedded Systems
Embedded Systems

Embedded systems comprise a single-chip microprocessor or microcontroller dedicated to performing one task or a few tasks. The software is embedded into read-only memory and enables the system to run a sequence of programmed instructions.

A common example of an embedded system is the anti-lock braking system (ABS) in automobiles. The key component of ABS is a small embedded system designed to detect wheel skidding and regulate brake pressure accordingly to optimize braking while maintaining wheel traction.

Other examples include home appliances like smart refrigerators, smart thermostats, smart door locks; consumer devices like fitness trackers, smart watches, e-readers; medical devices like blood analyzers, MRI scanners; industrial machines, robots; aviation and transportation systems like flight control, traffic signals, train control networks; etc. The applications of embedded devices are virtually limitless.

What is an Embedded System

How Does an Embedded System Work?

An embedded system is designed to perform predefined specialized computing functions within a larger system. It comprises three main components – the hardware, the embedded OS software, and the application software.

The hardware consists of the microprocessor/microcontroller along with the motherboard circuitry and associated interfaces like communication ports and user input/output interfaces. The embedded OS is the low-level software managing the hardware, I/O, scheduling tasks, memory allocation etc. The application software houses the specialized program logic implementing functions specific to the target device.

The OS software and application software are hosted in memory (ROM, RAM etc.) connected to the microprocessor and get executed sequentially by the CPU. The embedded system then electrically interfaces sensors, transducers, input buttons etc. and digital outputs like display screens, actuators etc. allowing it to monitor parameters via inputs and control behavior via outputs. All synchronized via real-time software coded with the system control logic.

How an Embedded System Communicates with the Outside World?

How an Embedded System Communicates with the Outside World
How an Embedded System Communicates with the Outside World

For any useful functionality, an embedded system needs to receive inputs from sensors and send outputs to actuators. Different standard digital communication buses and protocols enable information exchange with the outside world.

Some examples include:

●Serial buses like UART, SPI, I2C for short distance chip-to-chip communication
●USB, Ethernet for connecting peripheral devices
●Internet protocols like TCP/IP via WiFi/Ethernet for web connectivity
●Industrial buses like CANBUS, Modbus for factory sensor/actuator networks
●Audio/Video interfaces like HDMI, Bluetooth A2DP for multimedia
●Telecom protocols like GSM, LTE for wireless communication

The embedded firmware implements the specific protocol stacks required for the target system. The hardware interfaces like USB ports, GPIO lines enable connection to external peripherals.

What are the benefits of Embedded Systems?

Specialized Functionality
Embedded systems enable devices to deliver intelligent, precise and responsive functionality. Custom logic tailored for an exact purpose – unlike generic computing.

Real-Time Performance
Hard real-time response where delay cannot be tolerated – unlike time-shared generic OS.

Reliability
Critical systems require dependable and fault-tolerant performance. Watchdog timers and I/O diagnostics improve reliability.

Optimized Resources
With resource constraints, embedded systems are highly size, cost and power efficient versus alternatives.

Connectivity
Modern networked systems also provide web, mobile and cloud connectivity for remote monitoring and control.

Where to Use Embedded Systems?

Where to Use Embedded Systems
Where to Use Embedded Systems

Consumer Electronics
Embedded systems feature in most modern consumer electronic devices like smartphones, wearables, home automation systems, game consoles, etc. They enable responsive digital control and enhanced user experiences.

Industrial Automation
Running entire automated factory assembly lines, machine tools, robotic arms etc. Precision real-time motor control maximizes efficiency.

Automotive
Embedded computers regulate nearly all functions in automobiles – engine control units, transmission controllers, brake systems, advanced driver assistance systems etc.

Avionics
Flight management systems, aircraft control surfaces, in-flight entertainment systems etc. are managed by embedded computers for added reliability and flight optimization.

Medical Devices
X-ray machines, MRI scanners, lab diagnostic equipment, surgical tools etc. – embedded firmware controls therapeutic devices, enhancing healthcare.

Defense Systems
Modern weapon systems like missiles and radars depend on rugged, reliable embedded control solutions for precise response in extreme environments.

Transportation
Trains, traffic signals, logistic networks etc. use real-time connectivity and control for safe, efficient large-scale transportation infrastructure.

How to Use an Embedded System?

Learn Purposes
Research the embedded product’s intended functionality to appropriately integrate it into projects.

Consult Documentation
Thoroughly study technical manuals on hardware specifications, software libraries, interface protocols etc. before attempting integration.

Hardware Connections
Using pin diagrams and schematics, correctly wire power sources, actuators, sensors and peripheral devices to I/O interfaces.

Software Integration
Utilize firmware libraries, drivers and APIs appropriately in the application code development phase.

Validation Testing
Rigorously test pre-production prototypes simulating real-world operating conditions to validate functional performance.

Compliance Testing
Execute standardized tests mandated by regulatory bodies to achieve certifications like CE, FCC etc. where required.

Regular Maintenance
Periodically service equipment and troubleshoot issues to sustain dependable functionality post-deployment.

How to Design an Embedded System?

How to Design an Embedded System
How to Design an Embedded System

Requirements Analysis
Capture functional, and non-functional requirements and constraints of the target application via stakeholder input.

System Specification
Translate requirements into detailed technical specifications covering architecture, components, interfaces etc.

Design Process
With the product requirements analysis and system specification complete, the detailed design process involves:

Hardware Design
Create circuit schematics and PCB layouts – select microcontroller, peripherals and interfaces to meet specs.

Software Architecture
Define modular embedded application software architecture and interfaces based on functionality goals.

OS Selection
Choose a real-time operating system – bare metal vs Linux/RTOS etc. per complexity, performance, timeline and budget needs.

Programming
Code application and interface firmware as per architecture in languages like C, C++, Assembly etc. based on OS.

Enclosure Design
Model mechanical housing, human interface elements, cables/connectors etc. for robust product ergonomics.

Testing & Validation
Verify key functional performance metrics through rigorous lab tests on prototypes before launch.

Manufacturing
With design finalized, scale production via PCB assembly, parts procurement, final assembly, quality checks etc.

Conclusion

Embedded systems have revolutionized automation, machinery, instrumentation, transportation and consumer products delivering more intelligent, responsive and reliable functionality than ever.

From real-time control in mission critical defense systems to smart ambient connectivity in home appliances, embedded computing permeates nearly all digital machines.

With costs coming down and tools maturing, engineers continue finding innovative applications leveraging programmable embedded devices across industries.

FAQ

An embedded system is a computer system with a dedicated function within a larger electrical or mechanical system. It is embedded as part of a complete device often including hardware and mechanical parts.

  • Specialized Functionality
  • Real-Time Performance
  • Reliability
  • Optimized Resources
  • Connectivity
  • Consumer Electronics
  • Industrial Automation
  • Automotive
  • Avionics
  • Medical Devices
  • Defense Systems
  • Transportation

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