Embedded System || Introduction || Lesson-1

In this blog we will see
1. what is embedded system
2. Blocks of embedded system
3. Application domain of embedded system with example.

1. What is embedded system ?

Embedded means "Hidden Inside". What is embedded system ?

Embedded system, is a system of hardware and software is embedded into a larger system.

(e.g. washing machine is larger system containing mechanical parts and to perform functionalities of washing machine a electronic system of hardware and software is embedded into it, which will control larger system)

Embedded system is designed to perform a specific taskse.g. Embedded system present in Washing machine designed to perform tasks related to washing cloths only, it will not perform task of Digital Camera.

Embedded can be independent system e.g. digital calculator or part of larger system e.g. car having different embedded systems like one for controlling headlight or one for window control.

1.1 How does embedded system performs dedicated tasks ?

To perform dedicated task, embedded system uses a Micro-controller or micro-processor, piece of code is present inside micro-controller or micro-processor i.e. Embedded Software, this software is nothing but set of instructions to micro-controller or micro-processor to perform a task by controlling hardware. (Refer fig.1)

Embedded software contains logic to perform a task. Embedded  software is written by using Embedded C language. e.g. in case of washing machine, software has logic to perform task of washing clothes, if you press button start washing machine will start cleaning clothes.

Note : Micro-controller or micro-processois main processing unit of embedded system. 

Fig. 1 Embedded System

1.2 Application Areas of Embedded System :

Where embedded system is used in this world, Embedded system is used in many fields such as :

1. Medical : Health Monitoring devices e.g a device  (embedded system) which has a dedicated task to monitor patients heart rate and display it on screen.

2. Home Appliances : Embedded system is present in micro-wave oven which is designed to perform tasks related to heating the food.

3. Automotive : Many embedded systems are present in car e.g. Headlight control unit which is designed to control headlight based on inputs given by user with the help of switch. HAs dedicated tasks related to Turn ON/OFF headlights.

4. Aerospace : Many embedded systems are present in Airplane.  Embedded system is used to control engines of Airplane or another embedded system has dedicated task of control of wheels of airplane or shows position of aircraft.

5.Consumer Electronics : Embedded system used inside of digital camera, which has dedicated tasks related to click photos.

Fig.2 Embedded System Application Domains

2.  General View of an Embedded System :

Fig.3 Shows general view of an Embedded system. Important blocks of embedded system are :

1. Input : Inputs required in embedded system to provide user request (e.g. in case of Digital camera, a button to click photo) inputs to embedded system are connected to micro-controller / micro-processor based on inputs embedded system will perform some action (embedded software present inside Digital Camera will take a photo and save it in memory) this is output part of embedded system.

Inputs are provided from Sensors.

2. Outputs : Outputs are actions based on inputs, e.g. control of motor in case of washing machine or LED on-off  in bike headlamp. Actions are performed by embedded software.

Outputs are provided in form of an action.
Also it may be provided on screen as a feedback to user.

Fig. 3 General View of an Embedded system

3. Hardware Components : Hardware components are important part of embedded system. Main part of hardware is Micro-controller/ Micro-processor rest hardware is build around it. e.g. Sensors (to provide input), motors or LEDs (for output), LCD screen, switches, power supply, also electronic components like  diode, resistors, capacitor...etc

4. Software Component : Software components are brain of embedded system. Logic of task is defined in software component i.e. for input X perform action Y e.g. lets consider headlamp control unit , if switch is ON then turn Headlamp ON. Software is present inside micro-controller or micro-processor.

e.g Consider a washing machine, user of washing machine will press buttons present on washing machine to select water level, wash cycle and spin cycle, these buttons are connected to micro-controller or micro-processor and provides input to micro-controller or micro-processor. 

Based on inputs, software inside micro-controller or micro-processor, will calculate washing time and take action (filling water in machine, washing and drying clothes) and control other hardware part, such as motor to rotate drum and dry the clothes within time and displays information on screen and plays sound to indicate task (washing clothes) is done  i.e. output. 

4. Summary :

In this lesson you have learnt about what is embedded system, structure of embedded system, application domains and hardware-software part of embedded system. In next lesson we will discuss about micro-controllers.

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