Exploring the World of Embedded Systems: Here's All You Need to Know

As we observe the world around us, it becomes evident that our society increasingly relies on electronic devices that evolve with enhanced features and intelligence year after year. The computing power accessible to us today through these devices is equivalent to that of supercomputers from just a decade or even less ago. However, it is crucial to recognize that while the hardware has advanced significantly, the underlying software propels the IoT (Internet of Things) revolution.

In this post, we will delve into the realm of embedded systems and software, exploring the various methodologies employed in building these systems and software's profound influence on our daily lives. By gaining a deeper understanding of these concepts, we can appreciate the intricate workings of the technology surrounding us.

Definition of Embedded System

While a general-purpose computer typically encompasses a wide range of functionalities, including a screen, keyboard, and internet connectivity, embedded systems differ in appearance and purpose.

An embedded system is a compact electronic device, both small and large, designed to perform a specialized or limited set of functions. It incorporates integrated software that operates on microcontrollers and microprocessors. Unlike general-purpose computers, embedded systems may lack a screen and keyboard. Additionally, they can be either programmable or non-programmable, serving either as standalone devices or as components within larger systems.

Embedded systems are prevalent in everyday electronics, ranging from TV remote controls and microwave ovens to complex automotive sensor networks and advanced robotic equipment manufacturing. These devices use embedded software engineering to ensure proper functioning and efficient performance.

History of Embedded Systems

Embedded computer systems have indeed come a long way since the introduction of the Apollo Guidance Computer (AGC) in the 1960s. The AGC was a groundbreaking embedded system that played a crucial role in the Apollo spacecraft's navigation, guidance, and control. It introduced the concept of embedded operating systems in the field.

Over the years, embedded computer systems have become increasingly complex, requiring more advanced microcontroller technology. The evolution from 8-bit to 16-bit and eventually 32-bit microcontrollers has allowed greater processing power, memory capacity, and connectivity options. This advancement in microcontroller technology has enabled the development of more sophisticated embedded systems capable of handling complex tasks and supporting a wide range of applications. As embedded systems grow in complexity, operating systems have become essential for managing embedded software effectively.

How Does an Embedded System Work?

Many people often wonder about the inner workings of embedded systems due to their widespread use and the opportunities they provide for embedded software developers. Unlike a desktop PC that loads and runs various applications, an embedded system is designed to perform specific tasks and typically focuses on running a single application on a device.

Embedded operating systems have a limited scope of functions but must be highly reliable and seamlessly run on devices with specific sizes, processing power, and requirements. The success of the end product's functionality relies heavily on the performance of the embedded operating system. Several notable embedded operating systems have emerged as popular choices for commercial and industrial applications:

• Embedded Linux
• Wind River VxWorks
• QNX
• Android

These embedded operating systems provide developers with the tools, frameworks, and APIs to build and deploy applications specific to the targeted devices and industries. They offer various features such as task scheduling, memory management, device drivers, and networking protocols to support the development of reliable and efficient embedded solutions. As technology advances, embedded systems are becoming increasingly complex, requiring more sophisticated operating systems to handle the growing demands of modern applications.

Characteristics of Embedded Systems

Embedded systems exhibit several common characteristics that distinguish them from general-purpose computing devices. These features include:

• They are designed to perform specific functions or tasks repeatedly. 
• They are expected to perform their functions deterministically and reliably, consistently meeting strict timing requirements.
• They are typically built around microprocessors or microcontrollers, which provide the necessary computational power and control capabilities.
• They may operate without an operating system (bare metal) or use specialized operating systems like real-time operating systems (RTOS). 
• They work with limited resources, including memory, processing power, and energy. They are optimized to achieve maximum efficiency and reliability within these constraints.
• Depending on the application, they may or may not have user interfaces like keyboards or screens. Some may rely on other devices for user interaction, while others may operate autonomously.
• Embedded system designs are consciously devised with environmental factors in mind. They may be subjected to harsh conditions, such as extreme temperatures, humidity, or vibrations.

Components of Embedded Systems

Embedded systems consist of various components that work together to perform specific tasks. These components can be categorized into hardware and software elements:

Hardware Components

Hardware components play a crucial role in the functionality and performance of embedded systems. Here are the critical hardware components commonly found in embedded systems:

• Power Supply: The power supply provides the necessary electrical power to the embedded system. It can be sourced from batteries or wall adapters and should be stable and efficient to ensure continuous operation.
• Processor: The processor, also known as the central processing unit (CPU), acts as the brain of the embedded system. It determines the system's performance and capabilities. Processors can be microprocessors (general-purpose CPUs) or microcontrollers (integrated CPUs with peripherals).
• Memory: Embedded systems utilize different types of memory. RAM (Random Access Memory) temporarily stores data and variables during runtime, while ROM (Read-Only Memory) stores permanent data, such as firmware and program code. Flash memory is often used for non-volatile storage.
• Timers and Counters: They are essential for timekeeping and generating delays in an embedded system. They control events, measure time intervals, and synchronize operations.
• Communication Ports: They enable the embedded system to exchange data with other devices or systems. Standard communication interfaces include USB (Universal Serial Bus), UART (serial communication), RS-485 (serial communication over long distances), and Ethernet (network communication).
• Input and Output: Embedded systems require input and output capabilities to interact with the external environment. Input devices, such as sensors or user interfaces (buttons, switches), provide data to the system, while output devices, such as displays, LEDs, or actuators, convey information or trigger actions.
• Application-Specific Circuits: Depending on the application, embedded systems may incorporate additional circuits tailored to specific functionalities. These circuits can include ADCs (analog-to-digital converters), DACs (digital-to-analog converters), specialized sensor interfaces, or motor controllers.

Software Components

Various software components and tools come into play when designing an embedded system. Here are the critical software components commonly used:

• Assembler: Converts assembly language code into machine or object code that the target microprocessor or microcontroller can execute.
• Emulator: Enables execution and testing of embedded system software on a host system, simulating the behavior of the target hardware for debugging and issue resolution.
• Compiler: Translates high-level programming languages (e.g., C++ or C) into machine or object code that the embedded system can execute, performing optimizations and generating executable code.
• Integrated Development Environment (IDE): Provides a comprehensive development environment with features like code editing, compiling, debugging, and project management tools to facilitate the development process.
• Software Libraries: Pre-written code modules or functions that offer commonly used functionality or specific hardware interactions, aiding code simplification, size reduction, and reuse.
• Real-Time Operating System (RTOS): Specialized operating system designed for embedded systems with deterministic and real-time behavior, providing task scheduling, resource management, and inter-task communication capabilities.
• Middleware: Software components that bridge the gap between the operating system and application software, offering additional functionality and services such as communication protocols, data management, and networking capabilities.

Types of Embedded Systems

There are several types of embedded systems, each with its functional requirements. They include:

• Mobile Embedded Systems: These are small, lightweight systems designed for mobile devices. Examples include wearable devices, digital cameras, and smartphones.
• Networked Embedded Systems: These systems connect to a network and communicate with other devices. They often provide output or data to other devices through the network. Examples include point-of-sale (POS) systems, surveillance cameras, and home automation systems.
• Standalone Embedded Systems: Standalone embedded systems operate independently of a host system. They are self-contained and perform specific functions without relying on external devices. Examples include digital thermostats, calculators, and microwave ovens.
• Real-Time Embedded Systems: They are designed to respond to events or process data within strict timing constraints. They must produce the desired result within a predetermined timeframe. These systems are commonly used in industrial automation, healthcare, and military applications. Examples include medical monitoring devices, control systems for manufacturing machines, and flight control systems.

Conclusion

The world of embedded systems offers a fascinating and ever-expanding realm of possibilities. These systems have become integral to our modern lives with their compact size, specialized functions, and integration into various devices and industries. From mobile devices to networked systems and real-time applications, embedded systems have revolutionized how we interact with technology.

Skill-Lync offers comprehensive courses that cover the fundamental concepts, hardware, software, and practical skills needed to design and develop an embedded system. Talk to our experts to get a free demo of our embedded systems course.