Whilst the technology and expertise involved to build embedded systems may not be particularly complex, without these fixed systems many of the systems and devices that we rely on without realising would stop working effectively. If you’re an engineer or an employer in the embedded systems industry, it’s important to know what embedded systems are actually used for and what kind of projects they are likely to be involved in.
In this article, we answer questions like ‘What are embedded systems?’, ‘What is embedded software?’ and ‘Why are embedded systems important?’ to give an overview of what this kind of technology involves and is used for.
What is an Embedded System?
Embedded systems are a type of computer system that usually forms part of a larger system, device or piece of electronic equipment. They consist of a microcontroller that performs a specific function within a product and can be found in almost every modern piece of technology that we use today.
An embedded system is a reactive component, designed only to operate if it receives a specific signal in real-time. It communicates with the other components around it using sensors and actuators and will only perform its designated function if it receives the right response.
While an embedded system is often committed to only performing one task, it should not be confused with a dedicated system. The system gets its name from the fact that it is a fixed component inside a machine or device and cannot be moved, in comparison to a modular component which can be swapped out for something that has a different function.
A key feature of an embedded system is that it is small, low-cost and does not need a lot of power to operate. They are usually only made up of a power supply, communication ports, a processor and memory storage, and require minimal software to run and interact with other components, thanks to the fact that they usually only perform one, simple function.
Embedded System Components
The majority of embedded systems are quite simple, with a structure consisting of three different elements.
The first of these is the embedded system hardware, which is based around microprocessors and microcontrollers. A microprocessor is a CPU that uses external chips for memory and peripheral interfaces, and a microcontroller contains similar chips but these are inside the component instead of externally connected.
Other hardware in an embedded system includes sensors, actuators and A-D or D-A converters.
This hardware works in tandem with software and firmware that controls the specific function the embedded system performs. This software will be dependent on the processor speed and memory, but is usually very simple.
The final key component of an embedded system is a real-time operating system, which most but not all systems have. RTOS performs tasks and sends data about these tasks in real-time, whilst also setting and implementing rules about how long certain tasks should take.
The Purpose of Embedded Systems
The purpose of embedded systems is to control a specific function within a device. They are usually designed to only perform this function repeatedly, but more developed embedded systems can control entire operating systems.
Some more complex embedded systems can also perform several different functions, but these are still relatively simple tasks that do not require a large amount of processing power.
A key characteristic of embedded systems is that they aren’t usually programmable, so once they have been set up to perform a specific function they operate reliably and do not need to be tampered with. However, the software on some devices with embedded systems can be upgraded which means that programmed functions can be refined.
By being designed and programmed to only have one purpose, the functions of embedded systems make them reliable electronic component that does not need very much maintenance and is pretty easy to add to a device. Whilst they are a critical part of a system, they are very unlikely to malfunction and do not need reprogramming so are an essential part of many devices that are required just to function without intervention, like household appliances.
Types of Embedded Systems
Whilst most of these components are very similar in their design and purpose, there are several different categories of embedded systems that have different characteristics and require different levels of skill to design and install. You can get embedded systems that fit into multiple of these categories, such as mobile embedded systems that are also independent.
Real-Time Embedded System
The majority of embedded systems operate with real-time software, meaning that they give their required output function within a specified time interval. They are most commonly used in devices or systems that are time-critical and require a very reliable system to ensure functions are carried out when needed.
Network Embedded System
A network embedded system works in a device or machine that is connected to a network that provides output to other systems. They’re frequently found in home security systems where a small device is required to perform a simple function or respond to a specific input and then inform a wider, more complex system connected by a network.
Mobile Embedded System
Mobile embedded systems are any embedded systems used in small devices that are designed to be portable. As well as smartphones, they are found in digital cameras, watches and music players and are usually very simple and require minimal power and memory.
Independent Embedded System
An embedded system that is described as independent or stand-alone works by itself and does not require a host system, such as a computer, to carry out its function. It collects input data, processes this data and performs the required function without needing to connect to any other network or system. Common examples include temperature measurement devices or appliances like microwaves.
Where Embedded Systems are Used
The application of embedded systems is vast, from incredibly simple sets of components in small, stand-alone devices to more complex, reliable systems within wider machinery and networks that serve an overall purpose. Here are some of the most common examples of the use of embedded systems.
Modern automotive vehicles contain plenty of computers and embedded systems that are in charge of carrying out various specific functions within the vehicle. These tasks work together to make the car run but are all controlled on an individual level by embedded systems that are responding to different data and operating at different times. This reduces the cost of building each vehicle and also means that one small failure won’t affect the whole system.
Mobile phones consist of multiple different embedded systems that manage the operating system, camera, audio player, microphone and graphical user interface. The small size and power input that embedded systems need make them the best choice for devices like smartphones, as they don’t take up much space and are relatively economical to run alongside lots of other hardware and software.
As well as mobile phones, embedded systems are used in devices such as personal organisers, smartwatches and music players. Again, the small size of the system makes them a good choice for these devices, along with the fact that lots of different functions can be controlled at once without affecting each other. Smartwatches are also a good example of how software can be updated on an embedded system that cannot otherwise be reprogrammed, as users can sync their device to a computer and update the overall system.
More complex embedded systems are often used in medical equipment that requires repeated functions like sensing and mechanism control. Whilst there is often more nuanced digital function required when dealing with human health, certain embedded systems can ensure that time-sensitive functions are carried out or they’re used in user interfaces that link to more complex systems.
Automation is a big part of most industrial machinery, and embedded systems are key to getting machines to perform accurate, repeated actions. Sensors and other monitoring equipment are controlled by embedded systems, or occasionally a piece of industrial equipment is an entire embedded system itself.
There are a variety of different embedded systems involved in payment devices and systems that improve the security of money and personal detail transfer and make payments faster. Used in ATMs and point of sale (POS) systems, embedded systems control keypads, user interfaces, and security networks in payment transfers and withdrawals.
All kinds of communication processes involve embedded systems, from simple components of phones and other devices right the way up to aspects of telecommunication networks. A lot of satellite technology also makes use of embedded systems, although this kind of technology tends to be more complex than the systems you’ll find in phones or routers.
Home appliances are one of the biggest areas where embedded systems are used. Everything from microwaves to washing machines is often operated with multiple different embedded systems controlling everything from how long a machine runs to the user interface and when alarms are triggered. By individually controlling a range of functions, the appliances are very reliable and also don’t require a huge amount of processing power to efficiently operate.
A lot of home or corporate security systems use embedded systems to operate, allowing for relatively small and simple devices to be set up and manage the security of an entire building. The importance of embedded systems in security devices is critical, because it allows several different systems to monitor different elements of security through sensors and then report back to the embedded system’s microcontroller that will activate an alarm if something is detected.
A lot of the electronic equipment and devices used in the military and defence industries rely on embedded systems to efficiently operate. Areas such as surveillance, communication, data acquisition and storage all involve embedded systems in the equipment, and there is also a large sector of the engineering industry dedicated to improving the security of embedded system software to protect the information handled by these systems.
The use of embedded systems is widespread, and the technology and components that make up these systems are continuing to grow more advanced and refined. The benefits of having a system that performs a repeated function and does not require a huge amount of power or memory are great, and as the demand for automation in many areas increases, it is likely that the demand for embedded systems will only increase as well.
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