What is an embedded system?

Abstract image of a glowing processor being inserted onto a black motherboard
(Image credit: Shutterstock)

A microcontroller that sits inside a device to control a specific function within it is what we know as an embedded system. This could be, for example, your home’s central heating which is considered to be a type of embedded system.

Embedded systems feature prominently in consumer products and many household machines like toasters, washing machines and microwaves, but they are an essential part of most modern technologies.

Usually, embedded devices are not programmable as they are often designed with a single function in mind. However, depending on what the device is, the software can be upgraded. For example, fitness trackers can be upgraded by connecting them to a laptop or PC.

Because of this, embedded systems must be reliable, since a fault will probably result in the failure of a wider system function or an app, and fixing this can be a challenge.

Hardware foundations of an embedded system

Even though embedded systems used to be based on simple microprocessors, modern ones are usually designed from microcontrollers that come with a specific amount of built-in memory. The difference is that microprocessors only contain a central processing unit, which means that ROM and RAM must be added externally.

These systems appear in a number of forms, with some being stand-alone systems that don’t even have a host, like a video games console. They run certain tasks to a fixed schedule and are a real-time embedded system. A “Network-embedded” system is another example which, as you can probably guess from the name, is a device with a network connection like a mobile phone.

Key features of an embedded system

Embedded systems are typically designed to perform a single repeated function, although it’s true that some can be designed to control the entirety of an operating system. However, regardless of the function involved, they will very rarely be required to do anything more than this task – this makes it an exceptionally reliable component.

They’re described as ‘embedded’ because the component is fixed, and is critical to the overall operation of the system. Those that aren’t critical are described as modular, and can be swapped in and out to allow for new functionality.

Embedded systems are also characterised by their reactive nature. They communicate entirely through sensors or actuators, and if the right response isn’t provided in real-time, the response is considered incorrect and they will not function.

A microprocessor found inside a smartphone

(Image credit: Shutterstock)

Examples of embedded systems

Examples of embedded systems aren’t hard to find – chances are that you interact with at least a few of such devices on a daily basis. This is because embedded systems are seen in an overwhelming majority of consumer products, from something as small as your Fitbit watch, to your home’s central heating system.

Imagine a typical morning: you are woken up by your alarm clock and make your way to the kitchen, where you set your smart coffee machine to make you an espresso and throw some clothes in the washing machine. You take your car to work, and check the best route according to your GPS navigation system. During lunch break, you heat up your meal in the office microwave. An electronic calculator helps you work out some numbers which you need for a work report, which is in turn sent to your boss thanks to the Wi-Fi provided by your office router. At the end of the day, you check your watch to see whether you can get away with leaving five minutes early. On the way home, you stop by the gym, where your fitness tracker helps you determine your heart rate and the number of calories burnt during your workout. At home, you find some time at the end of the day to play video games on your console because, apparently, it can help level up your career.

All of the devices mentioned above are examples of embedded systems in everyday life. Although they might have different uses and are often sold in different stores, the mechanics behind them are actually pretty similar.

What are the benefits of an embedded system?

Embedded systems usually only have a single function, which means they are able to operate using very little power. They’re also usually very small, and can be crammed in alongside other components relatively easily. Combine all of this with the fact they’re relatively cheap, embedded systems are a hugely efficient means of controlling devices.

As you might have guessed, embedded systems are also incredibly low maintenance, and rarely require direct management, whether that’s changes at the hardware level or in programming.

A component that’s incredibly small, cheap, easy to maintain, and fantastic at doing a single task repeatedly, is the perfect fit for any ‘fire and forget’ devices – those that are required to operate with little fuss and intervention. A handy example of this are the entertainment systems in passenger planes, which were able to function using Windows XP for far longer than a commercial laptop.

What are the downsides of an embedded system?

Despite their invaluable benefits, embedded systems also come with some disadvantages that you should be aware of prior to investing in them. In that way, you can eliminate the element of surprise if something goes wrong, and even opt for a backup plan in case your business is reliant on an embedded system.

For one thing, it’s important to know that embedded systems tend to be difficult to upgrade to a new software or even fix in the event of a malfunction. This is due to the ‘embedded’ part of their nature, which translates to crucial parts being situated deep within the overall machine, and even the smallest change will massively impact the rest of the system.


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This means that embedded systems often are hard to successfully debug or fix, which often makes it necessary to deconstruct the entire device, removing the majority of components just to replace one part. In fact, the process can be so convoluted and tiresome that it’s often simpler and cheaper to simply replace the entire machine, which can still entail higher costs than anticipated for something which originally seemed like a ‘quick fix’.

However, the embedded systems’ component interdependability also means that, in some cases, tweaks can be applied to other, more accessible parts, which will then bring the device back to life or original purpose. This is why it’s important to have an understanding of how your embedded system works, as well as a trusted specialist who will be able to recognise the root cause of the problem.

Clare Hopping
Freelance writer

Clare is the founder of Blue Cactus Digital, a digital marketing company that helps ethical and sustainability-focused businesses grow their customer base.

Prior to becoming a marketer, Clare was a journalist, working at a range of mobile device-focused outlets including Know Your Mobile before moving into freelance life.

As a freelance writer, she drew on her expertise in mobility to write features and guides for ITPro, as well as regularly writing news stories on a wide range of topics.