Embedded System – A General Overview

No wonder we are hugely surrounded by computing systems. Look around; there are infinite examples of computing systems like – a digital camera, an electric trimmer, infotainment systems in car, smart refrigerator, washing machine, smart phone etc.

A computing system is one that can take an input (from the real world) does some processing based on that input and gives an output automatically. I am sure you could relate how all the above examples are computing systems. To elaborate more I take a simple example of ‘Auto Flash’ in digital camera. Now when you select this option, the camera automatically decide whether to ON or OFF the flash during the click depending upon the light or illumination present in the area. So the amount of light present in the area serves as input to the camera based on which it does processing. Thus, digital camera is a computing system.

All computing systems are composed of 'Embedded Systems' that perform the computing task for them. Embedded System is an electronic system composed of hardware & software and is programmed to perform certain specific task in a whole system.

Embedded System & Computer (Similarity & Difference)

Embedded System is a computer, just like computer it is composed of input, output and central processing unit. It is a combination of hardware & software and can be programmed (and reprogrammed) just like computer.

However a difference is that Embedded System is designed (programmed) to do specific task (it is not general purpose like computer). And thus as a result it has limited computing speed/capabilities (varies from application to application), limited memory, limited input/output ports etc. In embedded systems the central processing unit, memory, input/output ports etc are available on a single chip and we call it a Microcontroller.

So we conclude that an embedded system is a strip down version of a computer designed for specific application and has microcontroller as a central processing unit.

Why an embedded system is called an embedded system?

Embedded system is ‘embedded’ into a whole electrical and/or mechanical system and performs the computing task. You do not see it, you cannot touch it, you can just use it! For example embedded system is embedded into your fully automatic washing machine and automatically turns it off when clothes are washed; during power cuts it retains the settings and starts from where it left when power resumes, washes your clothes automatically based on the various different settings you have given as input. Similarly embedded systems are present in every modern-day car and give you a comfort of automatically connecting your mobile phone with car infotainment system, give you a comfort of cruise controls, automatic warning systems, alerts and what not!

Building an embedded system

Getting started with building embedded systems is quite very simple; But having said that it should also be comprehend that embedded systems are used in many mission critical applications, industrial applications, aerospace applications etc and can be very-very complex to design.

However the fact remains that the basic block diagram of a simple embedded system is similar to any complex embedded system. So if one can build simple embedded systems/applications he/she can very well build complex applications as well.

To getting started, these days there are lots of low cost microcontroller based hardware boards that are available in the market. They come with basic input/output peripherals, provision to connect lots of external input/output devices and provision to connect to computer through USB cable for programming and debugging. So you have complete hardware platform available to you. A few examples of such boards are Arduino, TI launchpad, Freedom board, Discovery board (pictures below). At software level you have various software programs (IDEs) where you can program these boards using C programming language.

Building embedded system is very fascinating! These days even school children are trying their hands with arduino. There are lots of hobbyists who build embedded systems for fun and learning. On a more serious front, it is not an understatement that in future every device that will run on electrical power will have an embedded system in it for sure. We are already seeing it become true. All the modern day electronic devices, gadgets, appliance that we use today feature embedded systems and it is just a matter of time when all our conventional devices will be replaced by these smart devices!

By Sagar Juneja - Research Associate, Chitkara University, H.P.